1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2013 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.nano; 32 33 import java.lang.reflect.Array; 34 import java.lang.reflect.Field; 35 import java.lang.reflect.InvocationTargetException; 36 import java.lang.reflect.Method; 37 import java.lang.reflect.Modifier; 38 import java.util.Map; 39 40 /** 41 * Static helper methods for printing nano protos. 42 * 43 * @author flynn@google.com Andrew Flynn 44 */ 45 public final class MessageNanoPrinter { 46 // Do not allow instantiation MessageNanoPrinter()47 private MessageNanoPrinter() {} 48 49 private static final String INDENT = " "; 50 private static final int MAX_STRING_LEN = 200; 51 52 /** 53 * Returns an text representation of a MessageNano suitable for debugging. The returned string 54 * is mostly compatible with Protocol Buffer's TextFormat (as provided by non-nano protocol 55 * buffers) -- groups (which are deprecated) are output with an underscore name (e.g. foo_bar 56 * instead of FooBar) and will thus not parse. 57 * 58 * <p>Employs Java reflection on the given object and recursively prints primitive fields, 59 * groups, and messages.</p> 60 */ print(T message)61 public static <T extends MessageNano> String print(T message) { 62 if (message == null) { 63 return ""; 64 } 65 66 StringBuffer buf = new StringBuffer(); 67 try { 68 print(null, message, new StringBuffer(), buf); 69 } catch (IllegalAccessException e) { 70 return "Error printing proto: " + e.getMessage(); 71 } catch (InvocationTargetException e) { 72 return "Error printing proto: " + e.getMessage(); 73 } 74 return buf.toString(); 75 } 76 77 /** 78 * Function that will print the given message/field into the StringBuffer. 79 * Meant to be called recursively. 80 * 81 * @param identifier the identifier to use, or {@code null} if this is the root message to 82 * print. 83 * @param object the value to print. May in fact be a primitive value or byte array and not a 84 * message. 85 * @param indentBuf the indentation each line should begin with. 86 * @param buf the output buffer. 87 */ print(String identifier, Object object, StringBuffer indentBuf, StringBuffer buf)88 private static void print(String identifier, Object object, 89 StringBuffer indentBuf, StringBuffer buf) throws IllegalAccessException, 90 InvocationTargetException { 91 if (object == null) { 92 // This can happen if... 93 // - we're about to print a message, String, or byte[], but it not present; 94 // - we're about to print a primitive, but "reftype" optional style is enabled, and 95 // the field is unset. 96 // In both cases the appropriate behavior is to output nothing. 97 } else if (object instanceof MessageNano) { // Nano proto message 98 int origIndentBufLength = indentBuf.length(); 99 if (identifier != null) { 100 buf.append(indentBuf).append(deCamelCaseify(identifier)).append(" <\n"); 101 indentBuf.append(INDENT); 102 } 103 Class<?> clazz = object.getClass(); 104 105 // Proto fields follow one of two formats: 106 // 107 // 1) Public, non-static variables that do not begin or end with '_' 108 // Find and print these using declared public fields 109 for (Field field : clazz.getFields()) { 110 int modifiers = field.getModifiers(); 111 String fieldName = field.getName(); 112 if ("cachedSize".equals(fieldName)) { 113 // TODO(bduff): perhaps cachedSize should have a more obscure name. 114 continue; 115 } 116 117 if ((modifiers & Modifier.PUBLIC) == Modifier.PUBLIC 118 && (modifiers & Modifier.STATIC) != Modifier.STATIC 119 && !fieldName.startsWith("_") 120 && !fieldName.endsWith("_")) { 121 Class<?> fieldType = field.getType(); 122 Object value = field.get(object); 123 124 if (fieldType.isArray()) { 125 Class<?> arrayType = fieldType.getComponentType(); 126 127 // bytes is special since it's not repeated, but is represented by an array 128 if (arrayType == byte.class) { 129 print(fieldName, value, indentBuf, buf); 130 } else { 131 int len = value == null ? 0 : Array.getLength(value); 132 for (int i = 0; i < len; i++) { 133 Object elem = Array.get(value, i); 134 print(fieldName, elem, indentBuf, buf); 135 } 136 } 137 } else { 138 print(fieldName, value, indentBuf, buf); 139 } 140 } 141 } 142 143 // 2) Fields that are accessed via getter methods (when accessors 144 // mode is turned on) 145 // Find and print these using getter methods. 146 for (Method method : clazz.getMethods()) { 147 String name = method.getName(); 148 // Check for the setter accessor method since getters and hazzers both have 149 // non-proto-field name collisions (hashCode() and getSerializedSize()) 150 if (name.startsWith("set")) { 151 String subfieldName = name.substring(3); 152 153 Method hazzer = null; 154 try { 155 hazzer = clazz.getMethod("has" + subfieldName); 156 } catch (NoSuchMethodException e) { 157 continue; 158 } 159 // If hazzer does't exist or returns false, no need to continue 160 if (!(Boolean) hazzer.invoke(object)) { 161 continue; 162 } 163 164 Method getter = null; 165 try { 166 getter = clazz.getMethod("get" + subfieldName); 167 } catch (NoSuchMethodException e) { 168 continue; 169 } 170 171 print(subfieldName, getter.invoke(object), indentBuf, buf); 172 } 173 } 174 if (identifier != null) { 175 indentBuf.setLength(origIndentBufLength); 176 buf.append(indentBuf).append(">\n"); 177 } 178 } else if (object instanceof Map) { 179 Map<?,?> map = (Map<?,?>) object; 180 identifier = deCamelCaseify(identifier); 181 182 for (Map.Entry<?,?> entry : map.entrySet()) { 183 buf.append(indentBuf).append(identifier).append(" <\n"); 184 int origIndentBufLength = indentBuf.length(); 185 indentBuf.append(INDENT); 186 print("key", entry.getKey(), indentBuf, buf); 187 print("value", entry.getValue(), indentBuf, buf); 188 indentBuf.setLength(origIndentBufLength); 189 buf.append(indentBuf).append(">\n"); 190 } 191 } else { 192 // Non-null primitive value 193 identifier = deCamelCaseify(identifier); 194 buf.append(indentBuf).append(identifier).append(": "); 195 if (object instanceof String) { 196 String stringMessage = sanitizeString((String) object); 197 buf.append("\"").append(stringMessage).append("\""); 198 } else if (object instanceof byte[]) { 199 appendQuotedBytes((byte[]) object, buf); 200 } else { 201 buf.append(object); 202 } 203 buf.append("\n"); 204 } 205 } 206 207 /** 208 * Converts an identifier of the format "FieldName" into "field_name". 209 */ deCamelCaseify(String identifier)210 private static String deCamelCaseify(String identifier) { 211 StringBuffer out = new StringBuffer(); 212 for (int i = 0; i < identifier.length(); i++) { 213 char currentChar = identifier.charAt(i); 214 if (i == 0) { 215 out.append(Character.toLowerCase(currentChar)); 216 } else if (Character.isUpperCase(currentChar)) { 217 out.append('_').append(Character.toLowerCase(currentChar)); 218 } else { 219 out.append(currentChar); 220 } 221 } 222 return out.toString(); 223 } 224 225 /** 226 * Shortens and escapes the given string. 227 */ sanitizeString(String str)228 private static String sanitizeString(String str) { 229 if (!str.startsWith("http") && str.length() > MAX_STRING_LEN) { 230 // Trim non-URL strings. 231 str = str.substring(0, MAX_STRING_LEN) + "[...]"; 232 } 233 return escapeString(str); 234 } 235 236 /** 237 * Escape everything except for low ASCII code points. 238 */ escapeString(String str)239 private static String escapeString(String str) { 240 int strLen = str.length(); 241 StringBuilder b = new StringBuilder(strLen); 242 for (int i = 0; i < strLen; i++) { 243 char original = str.charAt(i); 244 if (original >= ' ' && original <= '~' && original != '"' && original != '\'') { 245 b.append(original); 246 } else { 247 b.append(String.format("\\u%04x", (int) original)); 248 } 249 } 250 return b.toString(); 251 } 252 253 /** 254 * Appends a quoted byte array to the provided {@code StringBuffer}. 255 */ appendQuotedBytes(byte[] bytes, StringBuffer builder)256 private static void appendQuotedBytes(byte[] bytes, StringBuffer builder) { 257 if (bytes == null) { 258 builder.append("\"\""); 259 return; 260 } 261 262 builder.append('"'); 263 for (int i = 0; i < bytes.length; ++i) { 264 int ch = bytes[i] & 0xff; 265 if (ch == '\\' || ch == '"') { 266 builder.append('\\').append((char) ch); 267 } else if (ch >= 32 && ch < 127) { 268 builder.append((char) ch); 269 } else { 270 builder.append(String.format("\\%03o", ch)); 271 } 272 } 273 builder.append('"'); 274 } 275 } 276