ClassUtil (jackson-databind 2.8.0 API)

java.lang.Object
- com.fasterxml.jackson.databind.util.ClassUtil

public final class ClassUtil
extends Object

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`ClassUtil.Ctor` Value class used for caching Constructor declarations; used because caching done by JDK appears to be somewhat inefficient for some use cases.

Constructor Summary

Constructors
Constructor and Description

ClassUtil()

Constructors
Constructor and Description
`ClassUtil()`

Method Summary

Methods
Modifier and Type	Method and Description
`static String`	`canBeABeanType(Class<?> type)`
`static void`	`checkAndFixAccess(Member member)` Deprecated. Since 2.7 call variant that takes boolean flag.
`static void`	`checkAndFixAccess(Member member, boolean force)` Method that is called if a `Member` may need forced access, to force a field, method or constructor to be accessible: this is done by calling `AccessibleObject.setAccessible(boolean)`.
`static void`	`closeOnFailAndThrowAsIAE(JsonGenerator g, Closeable toClose, Exception fail)` Helper method that encapsulate logic in trying to close given `Closeable` in case of failure; useful mostly in forcing flush()ing as otherwise error conditions tend to be hard to diagnose.
`static void`	`closeOnFailAndThrowAsIAE(JsonGenerator g, Exception fail)` Helper method that encapsulate logic in trying to close output generator in case of failure; useful mostly in forcing flush()ing as otherwise error conditions tend to be hard to diagnose.
`static <T> T`	`createInstance(Class<T> cls, boolean canFixAccess)` Method that can be called to try to create an instantiate of specified type.
`static Object`	`defaultValue(Class<?> cls)` Helper method used to get default value for wrappers used for primitive types (0 for Integer etc)
`static <T> Iterator<T>`	`emptyIterator()`
`static Class<?>`	`findClass(String className)` Deprecated. Since 2.6, use method in `TypeFactory`.
`static Annotation[]`	`findClassAnnotations(Class<?> cls)`
`static <T> Constructor<T>`	`findConstructor(Class<T> cls, boolean canFixAccess)`
`static Class<? extends Enum<?>>`	`findEnumType(Class<?> cls)` Helper method that can be used to dynamically figure out formal enumeration type (class) for given class of an enumeration value.
`static Class<? extends Enum<?>>`	`findEnumType(Enum<?> en)` Helper method that can be used to dynamically figure out formal enumeration type (class) for given enumeration.
`static Class<? extends Enum<?>>`	`findEnumType(EnumMap<?,?> m)` Helper method that can be used to dynamically figure out enumeration type of given `EnumSet`, without having access to its declaration.
`static Class<? extends Enum<?>>`	`findEnumType(EnumSet<?> s)` Helper method that can be used to dynamically figure out enumeration type of given `EnumSet`, without having access to its declaration.
`static <T extends Annotation> Enum<?>`	`findFirstAnnotatedEnumValue(Class<Enum<?>> enumClass, Class<T> annotationClass)` A method that will look for the first Enum value annotated with the given Annotation.
`static List<Class<?>>`	`findRawSuperTypes(Class<?> cls, Class<?> endBefore, boolean addClassItself)`
`static List<Class<?>>`	`findSuperClasses(Class<?> cls, Class<?> endBefore, boolean addClassItself)` Method for finding all super classes (but not super interfaces) of given class, starting with the immediate super class and ending in the most distant one.
`static List<Class<?>>`	`findSuperTypes(Class<?> cls, Class<?> endBefore)` Deprecated.
`static List<Class<?>>`	`findSuperTypes(Class<?> cls, Class<?> endBefore, List<Class<?>> result)` Deprecated.
`static List<JavaType>`	`findSuperTypes(JavaType type, Class<?> endBefore, boolean addClassItself)` Method that will find all sub-classes and implemented interfaces of a given class or interface.
`static String`	`getClassDescription(Object classOrInstance)` Helper method used to construct appropriate description when passed either type (Class) or an instance; in latter case, class of instance is to be used.
`static ClassUtil.Ctor[]`	`getConstructors(Class<?> cls)`
`static Field[]`	`getDeclaredFields(Class<?> cls)`
`static Method[]`	`getDeclaredMethods(Class<?> cls)`
`static Class<?>`	`getDeclaringClass(Class<?> cls)`
`static Class<?>`	`getEnclosingClass(Class<?> cls)`
`static Type[]`	`getGenericInterfaces(Class<?> cls)`
`static Type`	`getGenericSuperclass(Class<?> cls)`
`static Class<?>`	`getOuterClass(Class<?> type)` Method for finding enclosing class for non-static inner classes
`static String`	`getPackageName(Class<?> cls)`
`static Throwable`	`getRootCause(Throwable t)` Method that can be used to find the "root cause", innermost of chained (wrapped) exceptions.
`static boolean`	`hasEnclosingMethod(Class<?> cls)`
`static boolean`	`hasGetterSignature(Method m)` Deprecated. Since 2.6 not used; may be removed before 3.x
`static boolean`	`isBogusClass(Class<?> cls)`
`static boolean`	`isCollectionMapOrArray(Class<?> type)`
`static boolean`	`isConcrete(Class<?> type)` Helper method that checks if given class is a concrete one; that is, not an interface or abstract class.
`static boolean`	`isConcrete(Member member)`
`static boolean`	`isJacksonStdImpl(Class<?> implClass)`
`static boolean`	`isJacksonStdImpl(Object impl)` Method that can be called to determine if given Object is the default implementation Jackson uses; as opposed to a custom serializer installed by a module or calling application.
`static String`	`isLocalType(Class<?> type, boolean allowNonStatic)`
`static boolean`	`isNonStaticInnerClass(Class<?> cls)`
`static boolean`	`isObjectOrPrimitive(Class<?> cls)`
`static boolean`	`isProxyType(Class<?> type)` Helper method used to weed out dynamic Proxy types; types that do not expose concrete method API that we could use to figure out automatic Bean (property) based serialization.
`static Class<?>`	`primitiveType(Class<?> type)` Method that can be used to find primitive type for given class if (but only if) it is either wrapper type or primitive type; returns `null` if type is neither.
`static void`	`throwAsIAE(Throwable t)` Method that will wrap 't' as an `IllegalArgumentException` if it is a checked exception; otherwise (runtime exception or error) throw as is
`static void`	`throwAsIAE(Throwable t, String msg)` Method that will wrap 't' as an `IllegalArgumentException` (and with specified message) if it is a checked exception; otherwise (runtime exception or error) throw as is
`static void`	`throwRootCause(Throwable t)` Method that will unwrap root causes of given Throwable, and throw the innermost `Exception` or `Error` as is.
`static Throwable`	`throwRootCauseIfIOE(Throwable t)` Method that works like `throwRootCause(java.lang.Throwable)` if (and only if) root cause is an `IOException`; otherwise returns root cause
`static void`	`unwrapAndThrowAsIAE(Throwable t)` Method that will locate the innermost exception for given Throwable; and then wrap it as an `IllegalArgumentException` if it is a checked exception; otherwise (runtime exception or error) throw as is
`static void`	`unwrapAndThrowAsIAE(Throwable t, String msg)` Method that will locate the innermost exception for given Throwable; and then wrap it as an `IllegalArgumentException` if it is a checked exception; otherwise (runtime exception or error) throw as is
`static Class<?>`	`wrapperType(Class<?> primitiveType)` Helper method for finding wrapper type for given primitive type (why isn't there one in JDK?)

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ClassUtil
```
public ClassUtil()
```
- Method Detail
  - emptyIterator
```
public static <T> Iterator<T> emptyIterator()
```
    Since:
    
    2.7
  - findSuperTypes
```
public static List<JavaType> findSuperTypes(JavaType type,
                            Class<?> endBefore,
                            boolean addClassItself)
```
    Method that will find all sub-classes and implemented interfaces of a given class or interface. Classes are listed in order of precedence, starting with the immediate super-class, followed by interfaces class directly declares to implemented, and then recursively followed by parent of super-class and so forth. Note that Object.class is not included in the list regardless of whether endBefore argument is defined or not.
    
    Parameters:
    endBefore - Super-type to NOT include in results, if any; when encountered, will be ignored (and no super types are checked).
    Since:
    
    2.7
  - findRawSuperTypes
```
public static List<Class<?>> findRawSuperTypes(Class<?> cls,
                               Class<?> endBefore,
                               boolean addClassItself)
```
    Since:
    
    2.7
  - findSuperClasses
```
public static List<Class<?>> findSuperClasses(Class<?> cls,
                              Class<?> endBefore,
                              boolean addClassItself)
```
    Method for finding all super classes (but not super interfaces) of given class, starting with the immediate super class and ending in the most distant one. Class itself is included if addClassItself is true.
    
    Since:
    
    2.7
  - findSuperTypes
```
@Deprecated
public static List<Class<?>> findSuperTypes(Class<?> cls,
                                       Class<?> endBefore)
```
    Deprecated.
  - findSuperTypes
```
@Deprecated
public static List<Class<?>> findSuperTypes(Class<?> cls,
                                       Class<?> endBefore,
                                       List<Class<?>> result)
```
    Deprecated.
  - canBeABeanType
```
public static String canBeABeanType(Class<?> type)
```
    Returns:
    Null if class might be a bean; type String (that identifies why it's not a bean) if not
  - isLocalType
```
public static String isLocalType(Class<?> type,
                 boolean allowNonStatic)
```
  - getOuterClass
```
public static Class<?> getOuterClass(Class<?> type)
```
    Method for finding enclosing class for non-static inner classes
  - isProxyType
```
public static boolean isProxyType(Class<?> type)
```
    Helper method used to weed out dynamic Proxy types; types that do not expose concrete method API that we could use to figure out automatic Bean (property) based serialization.
  - isConcrete
```
public static boolean isConcrete(Class<?> type)
```
    Helper method that checks if given class is a concrete one; that is, not an interface or abstract class.
  - isConcrete
```
public static boolean isConcrete(Member member)
```
  - isCollectionMapOrArray
```
public static boolean isCollectionMapOrArray(Class<?> type)
```
  - getClassDescription
```
public static String getClassDescription(Object classOrInstance)
```
    Helper method used to construct appropriate description when passed either type (Class) or an instance; in latter case, class of instance is to be used.
  - findClass
```
@Deprecated
public static Class<?> findClass(String className)
                          throws ClassNotFoundException
```
    Deprecated. Since 2.6, use method in TypeFactory.
    
    Throws:
    
    ClassNotFoundException
  - getPackageName
```
public static String getPackageName(Class<?> cls)
```
    Since:
    
    2.7
  - hasEnclosingMethod
```
public static boolean hasEnclosingMethod(Class<?> cls)
```
    Since:
    
    2.7
  - getDeclaredFields
```
public static Field[] getDeclaredFields(Class<?> cls)
```
    Since:
    
    2.7
  - getDeclaredMethods
```
public static Method[] getDeclaredMethods(Class<?> cls)
```
    Since:
    
    2.7
  - findClassAnnotations
```
public static Annotation[] findClassAnnotations(Class<?> cls)
```
    Since:
    
    2.7
  - getConstructors
```
public static ClassUtil.Ctor[] getConstructors(Class<?> cls)
```
    Since:
    
    2.7
  - getDeclaringClass
```
public static Class<?> getDeclaringClass(Class<?> cls)
```
    Since:
    
    2.7
  - getGenericSuperclass
```
public static Type getGenericSuperclass(Class<?> cls)
```
    Since:
    
    2.7
  - getGenericInterfaces
```
public static Type[] getGenericInterfaces(Class<?> cls)
```
    Since:
    
    2.7
  - getEnclosingClass
```
public static Class<?> getEnclosingClass(Class<?> cls)
```
    Since:
    
    2.7
  - hasGetterSignature
```
@Deprecated
public static boolean hasGetterSignature(Method m)
```
    Deprecated. Since 2.6 not used; may be removed before 3.x
  - getRootCause
```
public static Throwable getRootCause(Throwable t)
```
    Method that can be used to find the "root cause", innermost of chained (wrapped) exceptions.
  - throwRootCause
```
public static void throwRootCause(Throwable t)
                           throws Exception
```
    Method that will unwrap root causes of given Throwable, and throw the innermost Exception or Error as is. This is useful in cases where mandatory wrapping is added, which is often done by Reflection API.
    
    Throws:
    
    Exception
  - throwRootCauseIfIOE
```
public static Throwable throwRootCauseIfIOE(Throwable t)
                                     throws IOException
```
    Method that works like throwRootCause(java.lang.Throwable) if (and only if) root cause is an IOException; otherwise returns root cause
    
    Throws:
    
    IOException
    Since:
    
    2.8
  - throwAsIAE
```
public static void throwAsIAE(Throwable t)
```
    Method that will wrap 't' as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
  - throwAsIAE
```
public static void throwAsIAE(Throwable t,
              String msg)
```
    Method that will wrap 't' as an IllegalArgumentException (and with specified message) if it is a checked exception; otherwise (runtime exception or error) throw as is
  - unwrapAndThrowAsIAE
```
public static void unwrapAndThrowAsIAE(Throwable t)
```
    Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
  - unwrapAndThrowAsIAE
```
public static void unwrapAndThrowAsIAE(Throwable t,
                       String msg)
```
    Method that will locate the innermost exception for given Throwable; and then wrap it as an IllegalArgumentException if it is a checked exception; otherwise (runtime exception or error) throw as is
  - closeOnFailAndThrowAsIAE
```
public static void closeOnFailAndThrowAsIAE(JsonGenerator g,
                            Exception fail)
                                     throws IOException
```
    Helper method that encapsulate logic in trying to close output generator in case of failure; useful mostly in forcing flush()ing as otherwise error conditions tend to be hard to diagnose. However, it is often the case that output state may be corrupt so we need to be prepared for secondary exception without masking original one.
    
    Throws:
    
    IOException
    Since:
    
    2.8
  - closeOnFailAndThrowAsIAE
```
public static void closeOnFailAndThrowAsIAE(JsonGenerator g,
                            Closeable toClose,
                            Exception fail)
                                     throws IOException
```
    Helper method that encapsulate logic in trying to close given Closeable in case of failure; useful mostly in forcing flush()ing as otherwise error conditions tend to be hard to diagnose. However, it is often the case that output state may be corrupt so we need to be prepared for secondary exception without masking original one.
    
    Throws:
    
    IOException
    Since:
    
    2.8
  - createInstance
```
public static <T> T createInstance(Class<T> cls,
                   boolean canFixAccess)
                        throws IllegalArgumentException
```
    Method that can be called to try to create an instantiate of specified type. Instantiation is done using default no-argument constructor.
    
    Parameters:
    canFixAccess - Whether it is possible to try to change access rights of the default constructor (in case it is not publicly accessible) or not.
    
    Throws:
    
    IllegalArgumentException - If instantiation fails for any reason; except for cases where constructor throws an unchecked exception (which will be passed as is)
  - findConstructor
```
public static <T> Constructor<T> findConstructor(Class<T> cls,
                                 boolean canFixAccess)
                                      throws IllegalArgumentException
```
    Throws:
    
    IllegalArgumentException
  - defaultValue
```
public static Object defaultValue(Class<?> cls)
```
    Helper method used to get default value for wrappers used for primitive types (0 for Integer etc)
  - wrapperType
```
public static Class<?> wrapperType(Class<?> primitiveType)
```
    Helper method for finding wrapper type for given primitive type (why isn't there one in JDK?)
  - primitiveType
```
public static Class<?> primitiveType(Class<?> type)
```
    Method that can be used to find primitive type for given class if (but only if) it is either wrapper type or primitive type; returns `null` if type is neither.
    
    Since:
    
    2.7
  - checkAndFixAccess
```
@Deprecated
public static void checkAndFixAccess(Member member)
```
    Deprecated. Since 2.7 call variant that takes boolean flag.
    Equivalent to call:
```
   checkAndFixAccess(member, false);
```
  - checkAndFixAccess
```
public static void checkAndFixAccess(Member member,
                     boolean force)
```
    Method that is called if a Member may need forced access, to force a field, method or constructor to be accessible: this is done by calling AccessibleObject.setAccessible(boolean).
    
    Parameters:
    member - Accessor to call setAccessible() on.
    force - Whether to always try to make accessor accessible (true), or only if needed as per access rights (false)
    Since:
    
    2.7
  - findEnumType
```
public static Class<? extends Enum<?>> findEnumType(EnumSet<?> s)
```
    Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration. Code is needed to work around design flaw in JDK.
  - findEnumType
```
public static Class<? extends Enum<?>> findEnumType(EnumMap<?,?> m)
```
    Helper method that can be used to dynamically figure out enumeration type of given EnumSet, without having access to its declaration. Code is needed to work around design flaw in JDK.
  - findEnumType
```
public static Class<? extends Enum<?>> findEnumType(Enum<?> en)
```
    Helper method that can be used to dynamically figure out formal enumeration type (class) for given enumeration. This is either class of enum instance (for "simple" enumerations), or its superclass (for enums with instance fields or methods)
  - findEnumType
```
public static Class<? extends Enum<?>> findEnumType(Class<?> cls)
```
    Helper method that can be used to dynamically figure out formal enumeration type (class) for given class of an enumeration value. This is either class of enum instance (for "simple" enumerations), or its superclass (for enums with instance fields or methods)
  - findFirstAnnotatedEnumValue
```
public static <T extends Annotation> Enum<?> findFirstAnnotatedEnumValue(Class<Enum<?>> enumClass,
                                                         Class<T> annotationClass)
```
    A method that will look for the first Enum value annotated with the given Annotation.
    If there's more than one value annotated, the first one found will be returned. Which one exactly is used is undetermined.
    
    Parameters:
    enumClass - The Enum class to scan for a value with the given annotation
    annotationClass - The annotation to look for.
    
    Returns:
    the Enum value annotated with the given Annotation or null if none is found.
    
    Throws:
    
    IllegalArgumentException - if there's a reflection issue accessing the Enum
    Since:
    
    2.8
  - isJacksonStdImpl
```
public static boolean isJacksonStdImpl(Object impl)
```
    Method that can be called to determine if given Object is the default implementation Jackson uses; as opposed to a custom serializer installed by a module or calling application. Determination is done using JacksonStdImpl annotation on handler (serializer, deserializer etc) class.
  - isJacksonStdImpl
```
public static boolean isJacksonStdImpl(Class<?> implClass)
```
  - isBogusClass
```
public static boolean isBogusClass(Class<?> cls)
```
  - isNonStaticInnerClass
```
public static boolean isNonStaticInnerClass(Class<?> cls)
```
  - isObjectOrPrimitive
```
public static boolean isObjectOrPrimitive(Class<?> cls)
```
    Since:
    
    2.7

Class ClassUtil

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ClassUtil

Method Detail

emptyIterator

findSuperTypes

findRawSuperTypes

findSuperClasses

findSuperTypes

findSuperTypes

canBeABeanType

isLocalType

getOuterClass

isProxyType

isConcrete

isConcrete

isCollectionMapOrArray

getClassDescription

findClass

getPackageName

hasEnclosingMethod

getDeclaredFields

getDeclaredMethods

findClassAnnotations

getConstructors

getDeclaringClass

getGenericSuperclass

getGenericInterfaces

getEnclosingClass

hasGetterSignature

getRootCause

throwRootCause

throwRootCauseIfIOE

throwAsIAE

throwAsIAE

unwrapAndThrowAsIAE

unwrapAndThrowAsIAE

closeOnFailAndThrowAsIAE

closeOnFailAndThrowAsIAE

createInstance

findConstructor

defaultValue

wrapperType

primitiveType

checkAndFixAccess

checkAndFixAccess

findEnumType

findEnumType

findEnumType

findEnumType

findFirstAnnotatedEnumValue

isJacksonStdImpl

isJacksonStdImpl

isBogusClass

isNonStaticInnerClass

isObjectOrPrimitive