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1 /*
2  * Javassist, a Java-bytecode translator toolkit.
3  * Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved.
4  *
5  * The contents of this file are subject to the Mozilla Public License Version
6  * 1.1 (the "License"); you may not use this file except in compliance with
7  * the License.  Alternatively, the contents of this file may be used under
8  * the terms of the GNU Lesser General Public License Version 2.1 or later.
9  *
10  * Software distributed under the License is distributed on an "AS IS" basis,
11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12  * for the specific language governing rights and limitations under the
13  * License.
14  */
15 
16 package javassist;
17 
18 import java.io.BufferedOutputStream;
19 import java.io.ByteArrayOutputStream;
20 import java.io.DataOutputStream;
21 import java.io.File;
22 import java.io.FileOutputStream;
23 import java.io.IOException;
24 import java.io.OutputStream;
25 import java.net.URL;
26 import java.security.ProtectionDomain;
27 import java.util.Collection;
28 import javassist.bytecode.ClassFile;
29 import javassist.bytecode.Descriptor;
30 import javassist.bytecode.Opcode;
31 import javassist.expr.ExprEditor;
32 
33 /* Note:
34  *
35  * This class is an abstract class and several methods just return null
36  * or throw an exception.  Those methods are overridden in subclasses
37  * of this class.  Read the source code of CtClassType if you are
38  * interested in the implementation of Javassist.
39  *
40  * Subclasses of CtClass are CtClassType, CtPrimitiveType, and CtArray.
41  */
42 
43 /**
44  * An instance of <code>CtClass</code> represents a class.
45  * It is obtained from <code>ClassPool</code>.
46  *
47  * @see ClassPool#get(String)
48  */
49 public abstract class CtClass {
50     protected String qualifiedName;
51 
52     /**
53      * The version number of this release.
54      */
55     public static final String version = "3.14.0.GA";
56 
57     /**
58      * Prints the version number and the copyright notice.
59      *
60      * <p>The following command invokes this method:
61      *
62      * <ul><pre>java -jar javassist.jar</pre></ul>
63      */
main(String[] args)64     public static void main(String[] args) {
65         System.out.println("Javassist version " + CtClass.version);
66         System.out.println("Copyright (C) 1999-2010 Shigeru Chiba."
67                            + " All Rights Reserved.");
68     }
69 
70     static final String javaLangObject = "java.lang.Object";
71 
72     /**
73      * The <code>CtClass</code> object representing
74      * the <code>boolean</code> type.
75      */
76     public static CtClass booleanType;
77 
78     /**
79      * The <code>CtClass</code> object representing
80      * the <code>char</code> type.
81      */
82     public static CtClass charType;
83 
84     /**
85      * The <code>CtClass</code> object representing
86      * the <code>byte</code> type.
87      */
88     public static CtClass byteType;
89 
90     /**
91      * The <code>CtClass</code> object representing
92      * the <code>short</code> type.
93      */
94     public static CtClass shortType;
95 
96     /**
97      * The <code>CtClass</code> object representing
98      * the <code>int</code> type.
99      */
100     public static CtClass intType;
101 
102     /**
103      * The <code>CtClass</code> object representing
104      * the <code>long</code> type.
105      */
106     public static CtClass longType;
107 
108     /**
109      * The <code>CtClass</code> object representing
110      * the <code>float</code> type.
111      */
112     public static CtClass floatType;
113 
114     /**
115      * The <code>CtClass</code> object representing
116      * the <code>double</code> type.
117      */
118     public static CtClass doubleType;
119 
120     /**
121      * The <code>CtClass</code> object representing
122      * the <code>void</code> type.
123      */
124     public static CtClass voidType;
125 
126     static CtClass[] primitiveTypes;
127 
128     static {
129         primitiveTypes = new CtClass[9];
130 
131         booleanType =
132             new CtPrimitiveType("boolean", 'Z', "java.lang.Boolean",
133                                 "booleanValue", "()Z", Opcode.IRETURN,
134                                 Opcode.T_BOOLEAN, 1);
135         primitiveTypes[0] = booleanType;
136 
137         charType = new CtPrimitiveType("char", 'C', "java.lang.Character",
138                                        "charValue", "()C", Opcode.IRETURN,
139                                        Opcode.T_CHAR, 1);
140         primitiveTypes[1] = charType;
141 
142         byteType = new CtPrimitiveType("byte", 'B', "java.lang.Byte",
143                                        "byteValue", "()B", Opcode.IRETURN,
144                                        Opcode.T_BYTE, 1);
145         primitiveTypes[2] = byteType;
146 
147         shortType = new CtPrimitiveType("short", 'S', "java.lang.Short",
148                                         "shortValue", "()S", Opcode.IRETURN,
149                                         Opcode.T_SHORT, 1);
150         primitiveTypes[3] = shortType;
151 
152         intType = new CtPrimitiveType("int", 'I', "java.lang.Integer",
153                                       "intValue", "()I", Opcode.IRETURN,
154                                       Opcode.T_INT, 1);
155         primitiveTypes[4] = intType;
156 
157         longType = new CtPrimitiveType("long", 'J', "java.lang.Long",
158                                        "longValue", "()J", Opcode.LRETURN,
159                                        Opcode.T_LONG, 2);
160         primitiveTypes[5] = longType;
161 
162         floatType = new CtPrimitiveType("float", 'F', "java.lang.Float",
163                                         "floatValue", "()F", Opcode.FRETURN,
164                                         Opcode.T_FLOAT, 1);
165         primitiveTypes[6] = floatType;
166 
167         doubleType = new CtPrimitiveType("double", 'D', "java.lang.Double",
168                                          "doubleValue", "()D", Opcode.DRETURN,
169                                          Opcode.T_DOUBLE, 2);
170         primitiveTypes[7] = doubleType;
171 
172         voidType = new CtPrimitiveType("void", 'V', "java.lang.Void",
173                                        null, null, Opcode.RETURN, 0, 0);
174         primitiveTypes[8] = voidType;
175     }
176 
CtClass(String name)177     protected CtClass(String name) {
178         qualifiedName = name;
179     }
180 
181     /**
182      * Converts the object to a string.
183      */
toString()184     public String toString() {
185         StringBuffer buf = new StringBuffer(getClass().getName());
186         buf.append("@");
187         buf.append(Integer.toHexString(hashCode()));
188         buf.append("[");
189         extendToString(buf);
190         buf.append("]");
191         return buf.toString();
192     }
193 
194     /**
195      * Implemented in subclasses to add to the {@link #toString()} result.
196      * Subclasses should put a space before each token added to the buffer.
197      */
extendToString(StringBuffer buffer)198     protected void extendToString(StringBuffer buffer) {
199         buffer.append(getName());
200     }
201 
202     /**
203      * Returns a <code>ClassPool</code> for this class.
204      */
getClassPool()205     public ClassPool getClassPool() { return null; }
206 
207     /**
208      * Returns a class file for this class.
209      *
210      * <p>This method is not available if <code>isFrozen()</code>
211      * is true.
212      */
getClassFile()213     public ClassFile getClassFile() {
214         checkModify();
215         return getClassFile2();
216     }
217 
218     /**
219      * Returns a class file for this class (read only).
220      * Normal applications do not need calling this method.  Use
221      * <code>getClassFile()</code>.
222      *
223      * <p>The <code>ClassFile</code> object obtained by this method
224      * is read only.  Changes to this object might not be reflected
225      * on a class file generated by <code>toBytecode()</code>,
226      * <code>toClass()</code>, etc.
227      *
228      * <p>This method is available even if <code>isFrozen()</code>
229      * is true.  However, if the class is frozen, it might be also
230      * pruned.
231      *
232      * @see CtClass#getClassFile()
233      * @see CtClass#isFrozen()
234      * @see CtClass#prune()
235      */
getClassFile2()236     public ClassFile getClassFile2() { return null; }
237 
238     /**
239      * Undocumented method.  Do not use; internal-use only.
240      */
getAccessorMaker()241     public javassist.compiler.AccessorMaker getAccessorMaker() {
242         return null;
243     }
244 
245     /**
246      * Returns the uniform resource locator (URL) of the class file.
247      */
getURL()248     public URL getURL() throws NotFoundException {
249         throw new NotFoundException(getName());
250     }
251 
252     /**
253      * Returns true if the definition of the class has been modified.
254      */
isModified()255     public boolean isModified() { return false; }
256 
257     /**
258      * Returns true if the class has been loaded or written out
259      * and thus it cannot be modified any more.
260      *
261      * @see #defrost()
262      * @see #detach()
263      */
isFrozen()264     public boolean isFrozen() { return true; }
265 
266     /**
267      * Makes the class frozen.
268      *
269      * @see #isFrozen()
270      * @see #defrost()
271      * @since 3.6
272      */
freeze()273     public void freeze() {}
274 
275     /* Note: this method is overridden by CtClassType
276      */
checkModify()277     void checkModify() throws RuntimeException {
278         if (isFrozen())
279             throw new RuntimeException(getName() + " class is frozen");
280 
281         // isModified() must return true after this method is invoked.
282     }
283 
284     /**
285      * Defrosts the class so that the class can be modified again.
286      *
287      * <p>To avoid changes that will be never reflected,
288      * the class is frozen to be unmodifiable if it is loaded or
289      * written out.  This method should be called only in a case
290      * that the class will be reloaded or written out later again.
291      *
292      * <p>If <code>defrost()</code> will be called later, pruning
293      * must be disallowed in advance.
294      *
295      * @see #isFrozen()
296      * @see #stopPruning(boolean)
297      * @see #detach()
298      */
defrost()299     public void defrost() {
300         throw new RuntimeException("cannot defrost " + getName());
301     }
302 
303     /**
304      * Returns <code>true</code> if this object represents a primitive
305      * Java type: boolean, byte, char, short, int, long, float, double,
306      * or void.
307      */
isPrimitive()308     public boolean isPrimitive() { return false; }
309 
310     /**
311      * Returns <code>true</code> if this object represents an array type.
312      */
isArray()313     public boolean isArray() {
314         return false;
315     }
316 
317     /**
318      * If this object represents an array, this method returns the component
319      * type of the array.  Otherwise, it returns <code>null</code>.
320      */
getComponentType()321     public CtClass getComponentType() throws NotFoundException {
322         return null;
323     }
324 
325     /**
326      * Returns <code>true</code> if this class extends or implements
327      * <code>clazz</code>.  It also returns <code>true</code> if
328      * this class is the same as <code>clazz</code>.
329      */
subtypeOf(CtClass clazz)330     public boolean subtypeOf(CtClass clazz) throws NotFoundException {
331         return this == clazz || getName().equals(clazz.getName());
332     }
333 
334     /**
335      * Obtains the fully-qualified name of the class.
336      */
getName()337     public String getName() { return qualifiedName; }
338 
339     /**
340      * Obtains the not-qualified class name.
341      */
getSimpleName()342     public final String getSimpleName() {
343         String qname = qualifiedName;
344         int index = qname.lastIndexOf('.');
345         if (index < 0)
346             return qname;
347         else
348             return qname.substring(index + 1);
349     }
350 
351     /**
352      * Obtains the package name.  It may be <code>null</code>.
353      */
getPackageName()354     public final String getPackageName() {
355         String qname = qualifiedName;
356         int index = qname.lastIndexOf('.');
357         if (index < 0)
358             return null;
359         else
360             return qname.substring(0, index);
361     }
362 
363     /**
364      * Sets the class name
365      *
366      * @param name      fully-qualified name
367      */
setName(String name)368     public void setName(String name) {
369         checkModify();
370         if (name != null)
371             qualifiedName = name;
372     }
373 
374     /**
375      * Substitutes <code>newName</code> for all occurrences of a class
376      * name <code>oldName</code> in the class file.
377      *
378      * @param oldName           replaced class name
379      * @param newName           substituted class name
380      */
replaceClassName(String oldName, String newName)381     public void replaceClassName(String oldName, String newName) {
382         checkModify();
383     }
384 
385     /**
386      * Changes class names appearing in the class file according to the
387      * given <code>map</code>.
388      *
389      * <p>All the class names appearing in the class file are tested
390      * with <code>map</code> to determine whether each class name is
391      * replaced or not.  Thus this method can be used for collecting
392      * all the class names in the class file.  To do that, first define
393      * a subclass of <code>ClassMap</code> so that <code>get()</code>
394      * records all the given parameters.  Then, make an instance of
395      * that subclass as an empty hash-table.  Finally, pass that instance
396      * to this method.  After this method finishes, that instance would
397      * contain all the class names appearing in the class file.
398      *
399      * @param map       the hashtable associating replaced class names
400      *                  with substituted names.
401      */
replaceClassName(ClassMap map)402     public void replaceClassName(ClassMap map) {
403         checkModify();
404     }
405 
406     /**
407      * Returns a collection of the names of all the classes
408      * referenced in this class.
409      * That collection includes the name of this class.
410      *
411      * <p>This method may return <code>null</code>.
412      *
413      * @return a <code>Collection&lt;String&gt;</code> object.
414      */
getRefClasses()415     public synchronized Collection getRefClasses() {
416         ClassFile cf = getClassFile2();
417         if (cf != null) {
418             ClassMap cm = new ClassMap() {
419                 public void put(String oldname, String newname) {
420                     put0(oldname, newname);
421                 }
422 
423                 public Object get(Object jvmClassName) {
424                     String n = toJavaName((String)jvmClassName);
425                     put0(n, n);
426                     return null;
427                 }
428 
429                 public void fix(String name) {}
430             };
431             cf.getRefClasses(cm);
432             return cm.values();
433         }
434         else
435             return null;
436     }
437 
438     /**
439      * Determines whether this object represents a class or an interface.
440      * It returns <code>true</code> if this object represents an interface.
441      */
isInterface()442     public boolean isInterface() {
443         return false;
444     }
445 
446     /**
447      * Determines whether this object represents an annotation type.
448      * It returns <code>true</code> if this object represents an annotation type.
449      *
450      * @since 3.2
451      */
isAnnotation()452     public boolean isAnnotation() {
453         return false;
454     }
455 
456     /**
457      * Determines whether this object represents an enum.
458      * It returns <code>true</code> if this object represents an enum.
459      *
460      * @since 3.2
461      */
isEnum()462     public boolean isEnum() {
463         return false;
464     }
465 
466     /**
467      * Returns the modifiers for this class, encoded in an integer.
468      * For decoding, use <code>javassist.Modifier</code>.
469      *
470      * <p>If the class is a static nested class (a.k.a. static inner class),
471      * the returned modifiers include <code>Modifier.STATIC</code>.
472      *
473      * @see Modifier
474      */
getModifiers()475     public int getModifiers() {
476         return 0;
477     }
478 
479     /**
480      * Returns true if the class has the specified annotation class.
481      *
482      * @param clz the annotation class.
483      * @return <code>true</code> if the annotation is found, otherwise <code>false</code>.
484      * @since 3.11
485      */
hasAnnotation(Class clz)486     public boolean hasAnnotation(Class clz) {
487         return false;
488     }
489 
490     /**
491      * Returns the annotation if the class has the specified annotation class.
492      * For example, if an annotation <code>@Author</code> is associated
493      * with this class, an <code>Author</code> object is returned.
494      * The member values can be obtained by calling methods on
495      * the <code>Author</code> object.
496      *
497      * @param clz the annotation class.
498      * @return the annotation if found, otherwise <code>null</code>.
499      * @since 3.11
500      */
getAnnotation(Class clz)501     public Object getAnnotation(Class clz) throws ClassNotFoundException {
502         return null;
503     }
504 
505     /**
506      * Returns the annotations associated with this class.
507      * For example, if an annotation <code>@Author</code> is associated
508      * with this class, the returned array contains an <code>Author</code>
509      * object.  The member values can be obtained by calling methods on
510      * the <code>Author</code> object.
511      *
512      * @return an array of annotation-type objects.
513      * @see CtMember#getAnnotations()
514      * @since 3.1
515      */
getAnnotations()516     public Object[] getAnnotations() throws ClassNotFoundException {
517         return new Object[0];
518     }
519 
520     /**
521      * Returns the annotations associated with this class.
522      * This method is equivalent to <code>getAnnotations()</code>
523      * except that, if any annotations are not on the classpath,
524      * they are not included in the returned array.
525      *
526      * @return an array of annotation-type objects.
527      * @see #getAnnotations()
528      * @see CtMember#getAvailableAnnotations()
529      * @since 3.3
530      */
getAvailableAnnotations()531     public Object[] getAvailableAnnotations(){
532        return new Object[0];
533     }
534 
535     /**
536      * Returns an array of nested classes declared in the class.
537      * Nested classes are inner classes, anonymous classes, local classes,
538      * and static nested classes.
539      *
540      * @since 3.2
541      */
getNestedClasses()542     public CtClass[] getNestedClasses() throws NotFoundException {
543         return new CtClass[0];
544     }
545 
546     /**
547      * Sets the modifiers.
548      *
549      * <p>If the class is a nested class, this method also modifies
550      * the class declaring that nested class (i.e. the enclosing
551      * class is modified).
552      *
553      * @param mod       modifiers encoded by
554      *                  <code>javassist.Modifier</code>
555      * @see Modifier
556      */
setModifiers(int mod)557     public void setModifiers(int mod) {
558         checkModify();
559     }
560 
561     /**
562      * Determines whether the class directly or indirectly extends
563      * the given class.  If this class extends a class A and
564      * the class A extends a class B, then subclassof(B) returns true.
565      *
566      * <p>This method returns true if the given class is identical to
567      * the class represented by this object.
568      */
subclassOf(CtClass superclass)569     public boolean subclassOf(CtClass superclass) {
570         return false;
571     }
572 
573     /**
574      * Obtains the class object representing the superclass of the
575      * class.
576      * It returns null if this object represents the
577      * <code>java.lang.Object</code> class and thus it does not have
578      * the super class.
579      *
580      * <p>If this object represents an interface, this method
581      * always returns the <code>java.lang.Object</code> class.
582      * To obtain the super interfaces
583      * extended by that interface, call <code>getInterfaces()</code>.
584      */
getSuperclass()585     public CtClass getSuperclass() throws NotFoundException {
586         return null;
587     }
588 
589     /**
590      * Changes a super class unless this object represents an interface.
591      * The new super class must be compatible with the old one; for example,
592      * it should inherit from the old super class.
593      *
594      * <p>If this object represents an interface, this method is equivalent
595      * to <code>addInterface()</code>; it appends <code>clazz</code> to
596      * the list of the super interfaces extended by that interface.
597      * Note that an interface can extend multiple super interfaces.
598      *
599      * @see #replaceClassName(String, String)
600      * @see #replaceClassName(ClassMap)
601      */
setSuperclass(CtClass clazz)602     public void setSuperclass(CtClass clazz) throws CannotCompileException {
603         checkModify();
604     }
605 
606     /**
607      * Obtains the class objects representing the interfaces implemented
608      * by the class or, if this object represents an interface, the interfaces
609      * extended by that interface.
610      */
getInterfaces()611     public CtClass[] getInterfaces() throws NotFoundException {
612         return new CtClass[0];
613     }
614 
615     /**
616      * Sets implemented interfaces.  If this object represents an interface,
617      * this method sets the interfaces extended by that interface.
618      *
619      * @param list              a list of the <code>CtClass</code> objects
620      *                          representing interfaces, or
621      *                          <code>null</code> if the class implements
622      *                          no interfaces.
623      */
setInterfaces(CtClass[] list)624     public void setInterfaces(CtClass[] list) {
625         checkModify();
626     }
627 
628     /**
629      * Adds an interface.
630      *
631      * @param anInterface       the added interface.
632      */
addInterface(CtClass anInterface)633     public void addInterface(CtClass anInterface) {
634         checkModify();
635     }
636 
637     /**
638      * If this class is a member class or interface of another class,
639      * then the class enclosing this class is returned.
640      *
641      * @return null if this class is a top-level class or an anonymous class.
642      */
getDeclaringClass()643     public CtClass getDeclaringClass() throws NotFoundException {
644         return null;
645     }
646 
647     /**
648      * Returns the immediately enclosing method of this class.
649      * This method works only with JDK 1.5 or later.
650      *
651      * @return null if this class is not a local class or an anonymous
652      * class.
653      */
getEnclosingMethod()654     public CtMethod getEnclosingMethod() throws NotFoundException {
655         return null;
656     }
657 
658     /**
659      * Makes a new public nested class.  If this method is called,
660      * the <code>CtClass</code>, which encloses the nested class, is modified
661      * since a class file includes a list of nested classes.
662      *
663      * <p>The current implementation only supports a static nested class.
664      * <code>isStatic</code> must be true.
665      *
666      * @param name          the simple name of the nested class.
667      * @param isStatic      true if the nested class is static.
668      */
makeNestedClass(String name, boolean isStatic)669     public CtClass makeNestedClass(String name, boolean isStatic) {
670         throw new RuntimeException(getName() + " is not a class");
671     }
672 
673     /**
674      * Returns an array containing <code>CtField</code> objects
675      * representing all the non-private fields of the class.
676      * That array includes non-private fields inherited from the
677      * superclasses.
678      */
getFields()679     public CtField[] getFields() { return new CtField[0]; }
680 
681     /**
682      * Returns the field with the specified name.  The returned field
683      * may be a private field declared in a super class or interface.
684      */
getField(String name)685     public CtField getField(String name) throws NotFoundException {
686         return getField(name, null);
687     }
688 
689     /**
690      * Returns the field with the specified name and type.  The returned field
691      * may be a private field declared in a super class or interface.
692      * Unlike Java, the JVM allows a class to have
693      * multiple fields with the same name but different types.
694      *
695      * @param name      the field name.
696      * @param desc      the type descriptor of the field.  It is available by
697      *                  {@link CtField#getSignature()}.
698      * @see CtField#getSignature()
699      */
getField(String name, String desc)700     public CtField getField(String name, String desc) throws NotFoundException {
701         throw new NotFoundException(name);
702     }
703 
704     /**
705      * @return null     if the specified field is not found.
706      */
getField2(String name, String desc)707     CtField getField2(String name, String desc) { return null; }
708 
709     /**
710      * Gets all the fields declared in the class.  The inherited fields
711      * are not included.
712      *
713      * <p>Note: the result does not include inherited fields.
714      */
getDeclaredFields()715     public CtField[] getDeclaredFields() { return new CtField[0]; }
716 
717     /**
718      * Retrieves the field with the specified name among the fields
719      * declared in the class.
720      *
721      * <p>Note: this method does not search the super classes.
722      */
getDeclaredField(String name)723     public CtField getDeclaredField(String name) throws NotFoundException {
724         throw new NotFoundException(name);
725     }
726 
727     /**
728      * Retrieves the field with the specified name and type among the fields
729      * declared in the class.  Unlike Java, the JVM allows a class to have
730      * multiple fields with the same name but different types.
731      *
732      * <p>Note: this method does not search the super classes.
733      *
734      * @param name      the field name.
735      * @param desc      the type descriptor of the field.  It is available by
736      *                  {@link CtField#getSignature()}.
737      * @see CtField#getSignature()
738      */
getDeclaredField(String name, String desc)739     public CtField getDeclaredField(String name, String desc) throws NotFoundException {
740         throw new NotFoundException(name);
741     }
742 
743     /**
744      * Gets all the constructors and methods declared in the class.
745      */
getDeclaredBehaviors()746     public CtBehavior[] getDeclaredBehaviors() {
747         return new CtBehavior[0];
748     }
749 
750     /**
751      * Returns an array containing <code>CtConstructor</code> objects
752      * representing all the non-private constructors of the class.
753      */
getConstructors()754     public CtConstructor[] getConstructors() {
755         return new CtConstructor[0];
756     }
757 
758     /**
759      * Returns the constructor with the given signature,
760      * which is represented by a character string
761      * called method descriptor.
762      * For details of the method descriptor, see the JVM specification
763      * or <code>javassist.bytecode.Descriptor</code>.
764      *
765      * @param desc      method descriptor
766      * @see javassist.bytecode.Descriptor
767      */
getConstructor(String desc)768     public CtConstructor getConstructor(String desc)
769         throws NotFoundException
770     {
771         throw new NotFoundException("no such constructor");
772     }
773 
774     /**
775      * Gets all the constructors declared in the class.
776      *
777      * @see javassist.CtConstructor
778      */
getDeclaredConstructors()779     public CtConstructor[] getDeclaredConstructors() {
780         return new CtConstructor[0];
781     }
782 
783     /**
784      * Returns a constructor receiving the specified parameters.
785      *
786      * @param params    parameter types.
787      */
getDeclaredConstructor(CtClass[] params)788     public CtConstructor getDeclaredConstructor(CtClass[] params)
789         throws NotFoundException
790     {
791         String desc = Descriptor.ofConstructor(params);
792         return getConstructor(desc);
793     }
794 
795     /**
796      * Gets the class initializer (static constructor)
797      * declared in the class.
798      * This method returns <code>null</code> if
799      * no class initializer is not declared.
800      *
801      * @see #makeClassInitializer()
802      * @see javassist.CtConstructor
803      */
getClassInitializer()804     public CtConstructor getClassInitializer() {
805         return null;
806     }
807 
808     /**
809      * Returns an array containing <code>CtMethod</code> objects
810      * representing all the non-private methods of the class.
811      * That array includes non-private methods inherited from the
812      * superclasses.
813      */
getMethods()814     public CtMethod[] getMethods() {
815         return new CtMethod[0];
816     }
817 
818     /**
819      * Returns the method with the given name and signature.
820      * The returned method may be declared in a super class.
821      * The method signature is represented by a character string
822      * called method descriptor,
823      * which is defined in the JVM specification.
824      *
825      * @param name      method name
826      * @param desc      method descriptor
827      * @see CtBehavior#getSignature()
828      * @see javassist.bytecode.Descriptor
829      */
getMethod(String name, String desc)830     public CtMethod getMethod(String name, String desc)
831         throws NotFoundException
832     {
833         throw new NotFoundException(name);
834     }
835 
836     /**
837      * Gets all methods declared in the class.  The inherited methods
838      * are not included.
839      *
840      * @see javassist.CtMethod
841      */
getDeclaredMethods()842     public CtMethod[] getDeclaredMethods() {
843         return new CtMethod[0];
844     }
845 
846     /**
847      * Retrieves the method with the specified name and parameter types
848      * among the methods declared in the class.
849      *
850      * <p>Note: this method does not search the superclasses.
851      *
852      * @param name              method name
853      * @param params            parameter types
854      * @see javassist.CtMethod
855      */
getDeclaredMethod(String name, CtClass[] params)856     public CtMethod getDeclaredMethod(String name, CtClass[] params)
857         throws NotFoundException
858     {
859         throw new NotFoundException(name);
860     }
861 
862     /**
863      * Retrieves the method with the specified name among the methods
864      * declared in the class.  If there are multiple methods with
865      * the specified name, then this method returns one of them.
866      *
867      * <p>Note: this method does not search the superclasses.
868      *
869      * @see javassist.CtMethod
870      */
getDeclaredMethod(String name)871     public CtMethod getDeclaredMethod(String name) throws NotFoundException {
872         throw new NotFoundException(name);
873     }
874 
875     /**
876      * Makes an empty class initializer (static constructor).
877      * If the class already includes a class initializer,
878      * this method returns it.
879      *
880      * @see #getClassInitializer()
881      */
makeClassInitializer()882     public CtConstructor makeClassInitializer()
883         throws CannotCompileException
884     {
885         throw new CannotCompileException("not a class");
886     }
887 
888     /**
889      * Adds a constructor.  To add a class initializer (static constructor),
890      * call <code>makeClassInitializer()</code>.
891      *
892      * @see #makeClassInitializer()
893      */
addConstructor(CtConstructor c)894     public void addConstructor(CtConstructor c)
895         throws CannotCompileException
896     {
897         checkModify();
898     }
899 
900     /**
901      * Removes a constructor declared in this class.
902      *
903      * @param c     removed constructor.
904      * @throws NotFoundException   if the constructor is not found.
905      */
removeConstructor(CtConstructor c)906     public void removeConstructor(CtConstructor c) throws NotFoundException {
907         checkModify();
908     }
909 
910     /**
911      * Adds a method.
912      */
addMethod(CtMethod m)913     public void addMethod(CtMethod m) throws CannotCompileException {
914         checkModify();
915     }
916 
917     /**
918      * Removes a method declared in this class.
919      *
920      * @param m     removed method.
921      * @throws NotFoundException   if the method is not found.
922      */
removeMethod(CtMethod m)923     public void removeMethod(CtMethod m) throws NotFoundException {
924         checkModify();
925      }
926 
927     /**
928      * Adds a field.
929      *
930      * <p>The <code>CtField</code> belonging to another
931      * <code>CtClass</code> cannot be directly added to this class.
932      * Only a field created for this class can be added.
933      *
934      * @see javassist.CtField#CtField(CtField,CtClass)
935      */
addField(CtField f)936     public void addField(CtField f) throws CannotCompileException {
937         addField(f, (CtField.Initializer)null);
938     }
939 
940     /**
941      * Adds a field with an initial value.
942      *
943      * <p>The <code>CtField</code> belonging to another
944      * <code>CtClass</code> cannot be directly added to this class.
945      * Only a field created for this class can be added.
946      *
947      * <p>The initial value is given as an expression written in Java.
948      * Any regular Java expression can be used for specifying the initial
949      * value.  The followings are examples.
950      *
951      * <ul><pre>
952      * cc.addField(f, "0")               // the initial value is 0.
953      * cc.addField(f, "i + 1")           // i + 1.
954      * cc.addField(f, "new Point()");    // a Point object.
955      * </pre></ul>
956      *
957      * <p>Here, the type of variable <code>cc</code> is <code>CtClass</code>.
958      * The type of <code>f</code> is <code>CtField</code>.
959      *
960      * <p>Note: do not change the modifier of the field
961      * (in particular, do not add or remove <code>static</code>
962      * to/from the modifier)
963      * after it is added to the class by <code>addField()</code>.
964      *
965      * @param init      an expression for the initial value.
966      *
967      * @see javassist.CtField.Initializer#byExpr(String)
968      * @see javassist.CtField#CtField(CtField,CtClass)
969      */
addField(CtField f, String init)970     public void addField(CtField f, String init)
971         throws CannotCompileException
972     {
973         checkModify();
974     }
975 
976     /**
977      * Adds a field with an initial value.
978      *
979      * <p>The <code>CtField</code> belonging to another
980      * <code>CtClass</code> cannot be directly added to this class.
981      * Only a field created for this class can be added.
982      *
983      * <p>For example,
984      *
985      * <ul><pre>
986      * CtClass cc = ...;
987      * addField(new CtField(CtClass.intType, "i", cc),
988      *          CtField.Initializer.constant(1));
989      * </pre></ul>
990      *
991      * <p>This code adds an <code>int</code> field named "i".  The
992      * initial value of this field is 1.
993      *
994      * @param init      specifies the initial value of the field.
995      *
996      * @see javassist.CtField#CtField(CtField,CtClass)
997      */
addField(CtField f, CtField.Initializer init)998     public void addField(CtField f, CtField.Initializer init)
999         throws CannotCompileException
1000     {
1001         checkModify();
1002     }
1003 
1004     /**
1005      * Removes a field declared in this class.
1006      *
1007      * @param f     removed field.
1008      * @throws NotFoundException   if the field is not found.
1009      */
removeField(CtField f)1010     public void removeField(CtField f) throws NotFoundException {
1011         checkModify();
1012     }
1013 
1014     /**
1015      * Obtains an attribute with the given name.
1016      * If that attribute is not found in the class file, this
1017      * method returns null.
1018      *
1019      * <p>This is a convenient method mainly for obtaining
1020      * a user-defined attribute.  For dealing with attributes, see the
1021      * <code>javassist.bytecode</code> package.  For example, the following
1022      * expression returns all the attributes of a class file.
1023      *
1024      * <ul><pre>
1025      * getClassFile().getAttributes()
1026      * </pre></ul>
1027      *
1028      * @param name              attribute name
1029      * @see javassist.bytecode.AttributeInfo
1030      */
getAttribute(String name)1031     public byte[] getAttribute(String name) {
1032         return null;
1033     }
1034 
1035     /**
1036      * Adds a named attribute.
1037      * An arbitrary data (smaller than 64Kb) can be saved in the class
1038      * file.  Some attribute name are reserved by the JVM.
1039      * The attributes with the non-reserved names are ignored when a
1040      * class file is loaded into the JVM.
1041      * If there is already an attribute with
1042      * the same name, this method substitutes the new one for it.
1043      *
1044      * <p>This is a convenient method mainly for adding
1045      * a user-defined attribute.  For dealing with attributes, see the
1046      * <code>javassist.bytecode</code> package.  For example, the following
1047      * expression adds an attribute <code>info</code> to a class file.
1048      *
1049      * <ul><pre>
1050      * getClassFile().addAttribute(info)
1051      * </pre></ul>
1052      *
1053      * @param name      attribute name
1054      * @param data      attribute value
1055      * @see javassist.bytecode.AttributeInfo
1056      */
setAttribute(String name, byte[] data)1057     public void setAttribute(String name, byte[] data) {
1058         checkModify();
1059     }
1060 
1061     /**
1062      * Applies the given converter to all methods and constructors
1063      * declared in the class.  This method calls <code>instrument()</code>
1064      * on every <code>CtMethod</code> and <code>CtConstructor</code> object
1065      * in the class.
1066      *
1067      * @param converter         specifies how to modify.
1068      */
instrument(CodeConverter converter)1069     public void instrument(CodeConverter converter)
1070         throws CannotCompileException
1071     {
1072         checkModify();
1073     }
1074 
1075     /**
1076      * Modifies the bodies of all methods and constructors
1077      * declared in the class.  This method calls <code>instrument()</code>
1078      * on every <code>CtMethod</code> and <code>CtConstructor</code> object
1079      * in the class.
1080      *
1081      * @param editor            specifies how to modify.
1082      */
instrument(ExprEditor editor)1083     public void instrument(ExprEditor editor)
1084         throws CannotCompileException
1085     {
1086         checkModify();
1087     }
1088 
1089     /**
1090      * Converts this class to a <code>java.lang.Class</code> object.
1091      * Once this method is called, further modifications are not
1092      * allowed any more.
1093      * To load the class, this method uses the context class loader
1094      * of the current thread.  If the program is running on some application
1095      * server, the context class loader might be inappropriate to load the
1096      * class.
1097      *
1098      * <p>This method is provided for convenience.  If you need more
1099      * complex functionality, you should write your own class loader.
1100      *
1101      * <p>Note: this method calls <code>toClass()</code>
1102      * in <code>ClassPool</code>.
1103      *
1104      * <p><b>Warining:</b> A Class object returned by this method may not
1105      * work with a security manager or a signed jar file because a
1106      * protection domain is not specified.
1107      *
1108      * @see #toClass(java.lang.ClassLoader,ProtectionDomain)
1109      * @see ClassPool#toClass(CtClass)
1110      */
toClass()1111     public Class toClass() throws CannotCompileException {
1112         return getClassPool().toClass(this);
1113     }
1114 
1115     /**
1116      * Converts this class to a <code>java.lang.Class</code> object.
1117      * Once this method is called, further modifications are not allowed
1118      * any more.
1119      *
1120      * <p>The class file represented by this <code>CtClass</code> is
1121      * loaded by the given class loader to construct a
1122      * <code>java.lang.Class</code> object.  Since a private method
1123      * on the class loader is invoked through the reflection API,
1124      * the caller must have permissions to do that.
1125      *
1126      * <p>An easy way to obtain <code>ProtectionDomain</code> object is
1127      * to call <code>getProtectionDomain()</code>
1128      * in <code>java.lang.Class</code>.  It returns the domain that
1129      * the class belongs to.
1130      *
1131      * <p>This method is provided for convenience.  If you need more
1132      * complex functionality, you should write your own class loader.
1133      *
1134      * <p>Note: this method calls <code>toClass()</code>
1135      * in <code>ClassPool</code>.
1136      *
1137      * @param loader        the class loader used to load this class.
1138      *                      If it is null, the class loader returned by
1139      *                      {@link ClassPool#getClassLoader()} is used.
1140      * @param domain        the protection domain that the class belongs to.
1141      *                      If it is null, the default domain created
1142      *                      by <code>java.lang.ClassLoader</code> is used.
1143      * @see ClassPool#toClass(CtClass,java.lang.ClassLoader)
1144      * @since 3.3
1145      */
toClass(ClassLoader loader, ProtectionDomain domain)1146     public Class toClass(ClassLoader loader, ProtectionDomain domain)
1147         throws CannotCompileException
1148     {
1149         ClassPool cp = getClassPool();
1150         if (loader == null)
1151             loader = cp.getClassLoader();
1152 
1153         return cp.toClass(this, loader, domain);
1154     }
1155 
1156     /**
1157      * Converts this class to a <code>java.lang.Class</code> object.
1158      *
1159      * <p><b>Warining:</b> A Class object returned by this method may not
1160      * work with a security manager or a signed jar file because a
1161      * protection domain is not specified.
1162      *
1163      * @deprecated      Replaced by {@link #toClass(ClassLoader,ProtectionDomain)}
1164      */
toClass(ClassLoader loader)1165     public final Class toClass(ClassLoader loader)
1166         throws CannotCompileException
1167     {
1168         return getClassPool().toClass(this, loader);
1169     }
1170 
1171     /**
1172      * Removes this <code>CtClass</code> object from the
1173      * <code>ClassPool</code>.
1174      * After this method is called, any method cannot be called on the
1175      * removed <code>CtClass</code> object.
1176      *
1177      * <p>If <code>get()</code> in <code>ClassPool</code> is called
1178      * with the name of the removed method,
1179      * the <code>ClassPool</code> will read the class file again
1180      * and constructs another <code>CtClass</code> object representing
1181      * the same class.
1182      */
detach()1183     public void detach() {
1184         ClassPool cp = getClassPool();
1185         CtClass obj = cp.removeCached(getName());
1186         if (obj != this)
1187             cp.cacheCtClass(getName(), obj, false);
1188     }
1189 
1190     /**
1191      * Disallows (or allows) automatically pruning this <code>CtClass</code>
1192      * object.
1193      *
1194      * <p>
1195      * Javassist can automatically prune a <code>CtClass</code> object
1196      * when <code>toBytecode()</code> (or <code>toClass()</code>,
1197      * <code>writeFile()</code>) is called.
1198      * Since a <code>ClassPool</code> holds all instances of <code>CtClass</code>
1199      * even after <code>toBytecode()</code> (or <code>toClass()</code>,
1200      * <code>writeFile()</code>) is called, pruning may significantly
1201      * save memory consumption.
1202      *
1203      * <p>If <code>ClassPool.doPruning</code> is true, the automatic pruning
1204      * is on by default.  Otherwise, it is off.  The default value of
1205      * <code>ClassPool.doPruning</code> is false.
1206      *
1207      * @param stop      disallow pruning if true.  Otherwise, allow.
1208      * @return the previous status of pruning.  true if pruning is already stopped.
1209      *
1210      * @see #detach()
1211      * @see #prune()
1212      * @see ClassPool#doPruning
1213      */
stopPruning(boolean stop)1214     public boolean stopPruning(boolean stop) { return true; }
1215 
1216     /**
1217      * Discards unnecessary attributes, in particular,
1218      * <code>CodeAttribute</code>s (method bodies) of the class,
1219      * to minimize the memory footprint.
1220      * After calling this method, the class is read only.
1221      * It cannot be modified any more.
1222      * Furthermore, <code>toBytecode()</code>,
1223      * <code>writeFile()</code>, <code>toClass()</code>,
1224      * or <code>instrument()</code> cannot be called.
1225      * However, the method names and signatures in the class etc.
1226      * are still accessible.
1227      *
1228      * <p><code>toBytecode()</code>, <code>writeFile()</code>, and
1229      * <code>toClass()</code> internally call this method if
1230      * automatic pruning is on.
1231      *
1232      * <p>According to some experiments, pruning does not really reduce
1233      * memory consumption.  Only about 20%.  Since pruning takes time,
1234      * it might not pay off.  So the automatic pruning is off by default.
1235      *
1236      * @see #stopPruning(boolean)
1237      * @see #detach()
1238      * @see ClassPool#doPruning
1239      *
1240      * @see #toBytecode()
1241      * @see #toClass()
1242      * @see #writeFile()
1243      * @see #instrument(CodeConverter)
1244      * @see #instrument(ExprEditor)
1245      */
prune()1246     public void prune() {}
1247 
1248     /* Called by get() in ClassPool.
1249      * CtClassType overrides this method.
1250      */
incGetCounter()1251     void incGetCounter() {}
1252 
1253     /**
1254      * If this method is called, the class file will be
1255      * rebuilt when it is finally generated by
1256      * <code>toBytecode()</code> and <code>writeFile()</code>.
1257      * For a performance reason, the symbol table of the
1258      * class file may contain unused entries, for example,
1259      * after a method or a filed is deleted.
1260      * This method
1261      * removes those unused entries.  This removal will
1262      * minimize the size of the class file.
1263      *
1264      * @since 3.8.1
1265      */
rebuildClassFile()1266     public void rebuildClassFile() {}
1267 
1268     /**
1269      * Converts this class to a class file.
1270      * Once this method is called, further modifications are not
1271      * possible any more.
1272      *
1273      * @return the contents of the class file.
1274      */
toBytecode()1275     public byte[] toBytecode() throws IOException, CannotCompileException {
1276         ByteArrayOutputStream barray = new ByteArrayOutputStream();
1277         DataOutputStream out = new DataOutputStream(barray);
1278         try {
1279             toBytecode(out);
1280         }
1281         finally {
1282             out.close();
1283         }
1284 
1285         return barray.toByteArray();
1286     }
1287 
1288     /**
1289      * Writes a class file represented by this <code>CtClass</code>
1290      * object in the current directory.
1291      * Once this method is called, further modifications are not
1292      * possible any more.
1293      *
1294      * @see #debugWriteFile()
1295      */
writeFile()1296     public void writeFile()
1297         throws NotFoundException, IOException, CannotCompileException
1298     {
1299         writeFile(".");
1300     }
1301 
1302     /**
1303      * Writes a class file represented by this <code>CtClass</code>
1304      * object on a local disk.
1305      * Once this method is called, further modifications are not
1306      * possible any more.
1307      *
1308      * @param directoryName     it must end without a directory separator.
1309      * @see #debugWriteFile(String)
1310      */
writeFile(String directoryName)1311     public void writeFile(String directoryName)
1312         throws CannotCompileException, IOException
1313     {
1314         String classname = getName();
1315         String filename = directoryName + File.separatorChar
1316             + classname.replace('.', File.separatorChar) + ".class";
1317         int pos = filename.lastIndexOf(File.separatorChar);
1318         if (pos > 0) {
1319             String dir = filename.substring(0, pos);
1320             if (!dir.equals("."))
1321                 new File(dir).mkdirs();
1322         }
1323 
1324         DataOutputStream out
1325             = new DataOutputStream(new BufferedOutputStream(
1326                                 new DelayedFileOutputStream(filename)));
1327         try {
1328             toBytecode(out);
1329         }
1330         finally {
1331             out.close();
1332         }
1333     }
1334 
1335     /**
1336      * Writes a class file as <code>writeFile()</code> does although this
1337      * method does not prune or freeze the class after writing the class
1338      * file.  Note that, once <code>writeFile()</code> or <code>toBytecode()</code>
1339      * is called, it cannot be called again since the class is pruned and frozen.
1340      * This method would be useful for debugging.
1341      */
debugWriteFile()1342     public void debugWriteFile() {
1343         debugWriteFile(".");
1344     }
1345 
1346     /**
1347      * Writes a class file as <code>writeFile()</code> does although this
1348      * method does not prune or freeze the class after writing the class
1349      * file.  Note that, once <code>writeFile()</code> or <code>toBytecode()</code>
1350      * is called, it cannot be called again since the class is pruned and frozen.
1351      * This method would be useful for debugging.
1352      *
1353      * @param directoryName     it must end without a directory separator.
1354      */
debugWriteFile(String directoryName)1355     public void debugWriteFile(String directoryName) {
1356         try {
1357             boolean p = stopPruning(true);
1358             writeFile(directoryName);
1359             defrost();
1360             stopPruning(p);
1361         }
1362         catch (Exception e) {
1363             throw new RuntimeException(e);
1364         }
1365     }
1366 
1367     static class DelayedFileOutputStream extends OutputStream {
1368         private FileOutputStream file;
1369         private String filename;
1370 
DelayedFileOutputStream(String name)1371         DelayedFileOutputStream(String name) {
1372             file = null;
1373             filename = name;
1374         }
1375 
init()1376         private void init() throws IOException {
1377             if (file == null)
1378                 file = new FileOutputStream(filename);
1379         }
1380 
write(int b)1381         public void write(int b) throws IOException {
1382             init();
1383             file.write(b);
1384         }
1385 
write(byte[] b)1386         public void write(byte[] b) throws IOException {
1387             init();
1388             file.write(b);
1389         }
1390 
write(byte[] b, int off, int len)1391         public void write(byte[] b, int off, int len) throws IOException {
1392             init();
1393             file.write(b, off, len);
1394 
1395         }
1396 
flush()1397         public void flush() throws IOException {
1398             init();
1399             file.flush();
1400         }
1401 
close()1402         public void close() throws IOException {
1403             init();
1404             file.close();
1405         }
1406     }
1407 
1408     /**
1409      * Converts this class to a class file.
1410      * Once this method is called, further modifications are not
1411      * possible any more.
1412      *
1413      * <p>This method dose not close the output stream in the end.
1414      *
1415      * @param out       the output stream that a class file is written to.
1416      */
toBytecode(DataOutputStream out)1417     public void toBytecode(DataOutputStream out)
1418         throws CannotCompileException, IOException
1419     {
1420         throw new CannotCompileException("not a class");
1421     }
1422 
1423     /**
1424      * Makes a unique member name.  This method guarantees that
1425      * the returned name is not used as a prefix of any methods
1426      * or fields visible in this class.
1427      * If the returned name is XYZ, then any method or field names
1428      * in this class do not start with XYZ.
1429      *
1430      * @param prefix        the prefix of the member name.
1431      */
makeUniqueName(String prefix)1432     public String makeUniqueName(String prefix) {
1433         throw new RuntimeException("not available in " + getName());
1434     }
1435 
1436     /* Invoked from ClassPool#compress().
1437      * This method is overridden by CtClassType.
1438      */
compress()1439     void compress() {}
1440 }
1441