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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 package com.google.protobuf;
32 
33 import java.lang.reflect.Method;
34 import java.lang.reflect.Modifier;
35 import java.util.HashMap;
36 import java.util.Iterator;
37 import java.util.List;
38 import java.util.Map;
39 import java.util.Set;
40 import java.util.TreeSet;
41 
42 /** Helps generate {@link String} representations of {@link MessageLite} protos. */
43 final class MessageLiteToString {
44 
45   private static final String LIST_SUFFIX = "List";
46   private static final String BUILDER_LIST_SUFFIX = "OrBuilderList";
47   private static final String MAP_SUFFIX = "Map";
48   private static final String BYTES_SUFFIX = "Bytes";
49 
50   /**
51    * Returns a {@link String} representation of the {@link MessageLite} object. The first line of
52    * the {@code String} representation representation includes a comment string to uniquely identify
53    * the object instance. This acts as an indicator that this should not be relied on for
54    * comparisons.
55    *
56    * <p>For use by generated code only.
57    */
toString(MessageLite messageLite, String commentString)58   static String toString(MessageLite messageLite, String commentString) {
59     StringBuilder buffer = new StringBuilder();
60     buffer.append("# ").append(commentString);
61     reflectivePrintWithIndent(messageLite, buffer, 0);
62     return buffer.toString();
63   }
64 
65   /**
66    * Reflectively prints the {@link MessageLite} to the buffer at given {@code indent} level.
67    *
68    * @param buffer the buffer to write to
69    * @param indent the number of spaces to indent the proto by
70    */
reflectivePrintWithIndent( MessageLite messageLite, StringBuilder buffer, int indent)71   private static void reflectivePrintWithIndent(
72       MessageLite messageLite, StringBuilder buffer, int indent) {
73     // Build a map of method name to method. We're looking for methods like getFoo(), hasFoo(),
74     // getFooList() and getFooMap() which might be useful for building an object's string
75     // representation.
76     Map<String, Method> nameToNoArgMethod = new HashMap<String, Method>();
77     Map<String, Method> nameToMethod = new HashMap<String, Method>();
78     Set<String> getters = new TreeSet<String>();
79     for (Method method : messageLite.getClass().getDeclaredMethods()) {
80       nameToMethod.put(method.getName(), method);
81       if (method.getParameterTypes().length == 0) {
82         nameToNoArgMethod.put(method.getName(), method);
83 
84         if (method.getName().startsWith("get")) {
85           getters.add(method.getName());
86         }
87       }
88     }
89 
90     for (String getter : getters) {
91       String suffix = getter.replaceFirst("get", "");
92       if (suffix.endsWith(LIST_SUFFIX)
93           && !suffix.endsWith(BUILDER_LIST_SUFFIX)
94           // Sometimes people have fields named 'list' that aren't repeated.
95           && !suffix.equals(LIST_SUFFIX)) {
96         String camelCase =
97             suffix.substring(0, 1).toLowerCase()
98                 + suffix.substring(1, suffix.length() - LIST_SUFFIX.length());
99         // Try to reflectively get the value and toString() the field as if it were repeated. This
100         // only works if the method names have not been proguarded out or renamed.
101         Method listMethod = nameToNoArgMethod.get(getter);
102         if (listMethod != null && listMethod.getReturnType().equals(List.class)) {
103           printField(
104               buffer,
105               indent,
106               camelCaseToSnakeCase(camelCase),
107               GeneratedMessageLite.invokeOrDie(listMethod, messageLite));
108           continue;
109         }
110       }
111       if (suffix.endsWith(MAP_SUFFIX)
112           // Sometimes people have fields named 'map' that aren't maps.
113           && !suffix.equals(MAP_SUFFIX)) {
114         String camelCase =
115             suffix.substring(0, 1).toLowerCase()
116                 + suffix.substring(1, suffix.length() - MAP_SUFFIX.length());
117         // Try to reflectively get the value and toString() the field as if it were a map. This only
118         // works if the method names have not been proguarded out or renamed.
119         Method mapMethod = nameToNoArgMethod.get(getter);
120         if (mapMethod != null
121             && mapMethod.getReturnType().equals(Map.class)
122             // Skip the deprecated getter method with no prefix "Map" when the field name ends with
123             // "map".
124             && !mapMethod.isAnnotationPresent(Deprecated.class)
125             // Skip the internal mutable getter method.
126             && Modifier.isPublic(mapMethod.getModifiers())) {
127           printField(
128               buffer,
129               indent,
130               camelCaseToSnakeCase(camelCase),
131               GeneratedMessageLite.invokeOrDie(mapMethod, messageLite));
132           continue;
133         }
134       }
135 
136       Method setter = nameToMethod.get("set" + suffix);
137       if (setter == null) {
138         continue;
139       }
140       if (suffix.endsWith(BYTES_SUFFIX)
141           && nameToNoArgMethod.containsKey(
142               "get" + suffix.substring(0, suffix.length() - "Bytes".length()))) {
143         // Heuristic to skip bytes based accessors for string fields.
144         continue;
145       }
146 
147       String camelCase = suffix.substring(0, 1).toLowerCase() + suffix.substring(1);
148 
149       // Try to reflectively get the value and toString() the field as if it were optional. This
150       // only works if the method names have not been proguarded out or renamed.
151       Method getMethod = nameToNoArgMethod.get("get" + suffix);
152       Method hasMethod = nameToNoArgMethod.get("has" + suffix);
153       // TODO(dweis): Fix proto3 semantics.
154       if (getMethod != null) {
155         Object value = GeneratedMessageLite.invokeOrDie(getMethod, messageLite);
156         final boolean hasValue =
157             hasMethod == null
158                 ? !isDefaultValue(value)
159                 : (Boolean) GeneratedMessageLite.invokeOrDie(hasMethod, messageLite);
160         // TODO(dweis): This doesn't stop printing oneof case twice: value and enum style.
161         if (hasValue) {
162           printField(buffer, indent, camelCaseToSnakeCase(camelCase), value);
163         }
164         continue;
165       }
166     }
167 
168     if (messageLite instanceof GeneratedMessageLite.ExtendableMessage) {
169       Iterator<Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object>> iter =
170           ((GeneratedMessageLite.ExtendableMessage<?, ?>) messageLite).extensions.iterator();
171       while (iter.hasNext()) {
172         Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object> entry = iter.next();
173         printField(buffer, indent, "[" + entry.getKey().getNumber() + "]", entry.getValue());
174       }
175     }
176 
177     if (((GeneratedMessageLite<?, ?>) messageLite).unknownFields != null) {
178       ((GeneratedMessageLite<?, ?>) messageLite).unknownFields.printWithIndent(buffer, indent);
179     }
180   }
181 
isDefaultValue(Object o)182   private static boolean isDefaultValue(Object o) {
183     if (o instanceof Boolean) {
184       return !((Boolean) o);
185     }
186     if (o instanceof Integer) {
187       return ((Integer) o) == 0;
188     }
189     if (o instanceof Float) {
190       return ((Float) o) == 0f;
191     }
192     if (o instanceof Double) {
193       return ((Double) o) == 0d;
194     }
195     if (o instanceof String) {
196       return o.equals("");
197     }
198     if (o instanceof ByteString) {
199       return o.equals(ByteString.EMPTY);
200     }
201     if (o instanceof MessageLite) { // Can happen in oneofs.
202       return o == ((MessageLite) o).getDefaultInstanceForType();
203     }
204     if (o instanceof java.lang.Enum<?>) { // Catches oneof enums.
205       return ((java.lang.Enum<?>) o).ordinal() == 0;
206     }
207 
208     return false;
209   }
210 
211   /**
212    * Formats a text proto field.
213    *
214    * <p>For use by generated code only.
215    *
216    * @param buffer the buffer to write to
217    * @param indent the number of spaces the proto should be indented by
218    * @param name the field name (in lower underscore case)
219    * @param object the object value of the field
220    */
printField(StringBuilder buffer, int indent, String name, Object object)221   static final void printField(StringBuilder buffer, int indent, String name, Object object) {
222     if (object instanceof List<?>) {
223       List<?> list = (List<?>) object;
224       for (Object entry : list) {
225         printField(buffer, indent, name, entry);
226       }
227       return;
228     }
229     if (object instanceof Map<?, ?>) {
230       Map<?, ?> map = (Map<?, ?>) object;
231       for (Map.Entry<?, ?> entry : map.entrySet()) {
232         printField(buffer, indent, name, entry);
233       }
234       return;
235     }
236 
237     buffer.append('\n');
238     for (int i = 0; i < indent; i++) {
239       buffer.append(' ');
240     }
241     buffer.append(name);
242 
243     if (object instanceof String) {
244       buffer.append(": \"").append(TextFormatEscaper.escapeText((String) object)).append('"');
245     } else if (object instanceof ByteString) {
246       buffer.append(": \"").append(TextFormatEscaper.escapeBytes((ByteString) object)).append('"');
247     } else if (object instanceof GeneratedMessageLite) {
248       buffer.append(" {");
249       reflectivePrintWithIndent((GeneratedMessageLite<?, ?>) object, buffer, indent + 2);
250       buffer.append("\n");
251       for (int i = 0; i < indent; i++) {
252         buffer.append(' ');
253       }
254       buffer.append("}");
255     } else if (object instanceof Map.Entry<?, ?>) {
256       buffer.append(" {");
257       Map.Entry<?, ?> entry = (Map.Entry<?, ?>) object;
258       printField(buffer, indent + 2, "key", entry.getKey());
259       printField(buffer, indent + 2, "value", entry.getValue());
260       buffer.append("\n");
261       for (int i = 0; i < indent; i++) {
262         buffer.append(' ');
263       }
264       buffer.append("}");
265     } else {
266       buffer.append(": ").append(object.toString());
267     }
268   }
269 
camelCaseToSnakeCase(String camelCase)270   private static final String camelCaseToSnakeCase(String camelCase) {
271     StringBuilder builder = new StringBuilder();
272     for (int i = 0; i < camelCase.length(); i++) {
273       char ch = camelCase.charAt(i);
274       if (Character.isUpperCase(ch)) {
275         builder.append("_");
276       }
277       builder.append(Character.toLowerCase(ch));
278     }
279     return builder.toString();
280   }
281 }
282