/* * Copyright 2008 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.google.gwt.user.server.rpc.impl; import com.google.gwt.user.client.rpc.CustomFieldSerializer; import com.google.gwt.user.client.rpc.SerializationException; import com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter; import com.google.gwt.user.server.Base64Utils; import com.google.gwt.user.server.rpc.SerializationPolicy; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectOutputStream; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.util.ArrayList; import java.util.IdentityHashMap; import java.util.List; import java.util.ListIterator; import java.util.Map; import java.util.Set; /** * For internal use only. Used for server call serialization. This class is * carefully matched with the client-side version. */ public final class ServerSerializationStreamWriter extends AbstractSerializationStreamWriter { /** * Builds a string that evaluates into an array containing the given elements. * This class exists to work around a bug in IE6/7 that limits the size of * array literals. */ public static class LengthConstrainedArray { public static final int MAXIMUM_ARRAY_LENGTH = 1 << 15; private static final String POSTLUDE = "])"; private static final String PRELUDE = "].concat(["; private final StringBuffer buffer; private int count = 0; private boolean needsComma = false; private int total = 0; public LengthConstrainedArray() { buffer = new StringBuffer(); } public LengthConstrainedArray(int capacityGuess) { buffer = new StringBuffer(capacityGuess); } public void addToken(CharSequence token) { total++; if (count++ == MAXIMUM_ARRAY_LENGTH) { if (total == MAXIMUM_ARRAY_LENGTH + 1) { buffer.append(PRELUDE); } else { buffer.append("],["); } count = 0; needsComma = false; } if (needsComma) { buffer.append(","); } else { needsComma = true; } buffer.append(token); } public void addToken(int i) { addToken(String.valueOf(i)); } @Override public String toString() { if (total > MAXIMUM_ARRAY_LENGTH) { return "[" + buffer.toString() + POSTLUDE; } else { return "[" + buffer.toString() + "]"; } } } /** * Enumeration used to provided typed instance writers. */ private enum ValueWriter { BOOLEAN { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeBoolean(((Boolean) instance).booleanValue()); } }, BYTE { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeByte(((Byte) instance).byteValue()); } }, CHAR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeChar(((Character) instance).charValue()); } }, DOUBLE { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeDouble(((Double) instance).doubleValue()); } }, FLOAT { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeFloat(((Float) instance).floatValue()); } }, INT { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeInt(((Integer) instance).intValue()); } }, LONG { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeLong(((Long) instance).longValue()); } }, OBJECT { @Override void write(ServerSerializationStreamWriter stream, Object instance) throws SerializationException { stream.writeObject(instance); } }, SHORT { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeShort(((Short) instance).shortValue()); } }, STRING { @Override void write(ServerSerializationStreamWriter stream, Object instance) { stream.writeString((String) instance); } }; abstract void write(ServerSerializationStreamWriter stream, Object instance) throws SerializationException; } /** * Enumeration used to provided typed vector writers. */ private enum VectorWriter { BOOLEAN_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { boolean[] vector = (boolean[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeBoolean(vector[i]); } } }, BYTE_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { byte[] vector = (byte[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeByte(vector[i]); } } }, CHAR_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { char[] vector = (char[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeChar(vector[i]); } } }, DOUBLE_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { double[] vector = (double[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeDouble(vector[i]); } } }, FLOAT_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { float[] vector = (float[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeFloat(vector[i]); } } }, INT_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { int[] vector = (int[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeInt(vector[i]); } } }, LONG_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { long[] vector = (long[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeLong(vector[i]); } } }, OBJECT_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) throws SerializationException { Object[] vector = (Object[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeObject(vector[i]); } } }, SHORT_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { short[] vector = (short[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeShort(vector[i]); } } }, STRING_VECTOR { @Override void write(ServerSerializationStreamWriter stream, Object instance) { String[] vector = (String[]) instance; stream.writeInt(vector.length); for (int i = 0, n = vector.length; i < n; ++i) { stream.writeString(vector[i]); } } }; abstract void write(ServerSerializationStreamWriter stream, Object instance) throws SerializationException; } /** * Map of {@link Class} objects to {@link ValueWriter}s. */ private static final Map<Class<?>, ValueWriter> CLASS_TO_VALUE_WRITER = new IdentityHashMap<Class<?>, ValueWriter>(); /** * Map of {@link Class} vector objects to {@link VectorWriter}s. */ private static final Map<Class<?>, VectorWriter> CLASS_TO_VECTOR_WRITER = new IdentityHashMap<Class<?>, VectorWriter>(); /** * Number of escaped JS Chars. */ private static final int NUMBER_OF_JS_ESCAPED_CHARS = 128; /** * A list of any characters that need escaping when printing a JavaScript * string literal. Contains a 0 if the character does not need escaping, * otherwise contains the character to escape with. */ private static final char[] JS_CHARS_ESCAPED = new char[NUMBER_OF_JS_ESCAPED_CHARS]; /** * This defines the character used by JavaScript to mark the start of an * escape sequence. */ private static final char JS_ESCAPE_CHAR = '\\'; /** * This defines the character used to enclose JavaScript strings. */ private static final char JS_QUOTE_CHAR = '\"'; /** * Index into this array using a nibble, 4 bits, to get the corresponding * hexa-decimal character representation. */ private static final char NIBBLE_TO_HEX_CHAR[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; private static final char NON_BREAKING_HYPHEN = '\u2011'; static { /* * NOTE: The JS VM in IE6 & IE7 do not interpret \v correctly. They convert * JavaScript Vertical Tab character '\v' into 'v'. As such, we do not use * the short form of the unicode escape here. */ JS_CHARS_ESCAPED['\u0000'] = '0'; JS_CHARS_ESCAPED['\b'] = 'b'; JS_CHARS_ESCAPED['\t'] = 't'; JS_CHARS_ESCAPED['\n'] = 'n'; JS_CHARS_ESCAPED['\f'] = 'f'; JS_CHARS_ESCAPED['\r'] = 'r'; JS_CHARS_ESCAPED[JS_ESCAPE_CHAR] = JS_ESCAPE_CHAR; JS_CHARS_ESCAPED[JS_QUOTE_CHAR] = JS_QUOTE_CHAR; CLASS_TO_VECTOR_WRITER.put(boolean[].class, VectorWriter.BOOLEAN_VECTOR); CLASS_TO_VECTOR_WRITER.put(byte[].class, VectorWriter.BYTE_VECTOR); CLASS_TO_VECTOR_WRITER.put(char[].class, VectorWriter.CHAR_VECTOR); CLASS_TO_VECTOR_WRITER.put(double[].class, VectorWriter.DOUBLE_VECTOR); CLASS_TO_VECTOR_WRITER.put(float[].class, VectorWriter.FLOAT_VECTOR); CLASS_TO_VECTOR_WRITER.put(int[].class, VectorWriter.INT_VECTOR); CLASS_TO_VECTOR_WRITER.put(long[].class, VectorWriter.LONG_VECTOR); CLASS_TO_VECTOR_WRITER.put(Object[].class, VectorWriter.OBJECT_VECTOR); CLASS_TO_VECTOR_WRITER.put(short[].class, VectorWriter.SHORT_VECTOR); CLASS_TO_VECTOR_WRITER.put(String[].class, VectorWriter.STRING_VECTOR); CLASS_TO_VALUE_WRITER.put(boolean.class, ValueWriter.BOOLEAN); CLASS_TO_VALUE_WRITER.put(byte.class, ValueWriter.BYTE); CLASS_TO_VALUE_WRITER.put(char.class, ValueWriter.CHAR); CLASS_TO_VALUE_WRITER.put(double.class, ValueWriter.DOUBLE); CLASS_TO_VALUE_WRITER.put(float.class, ValueWriter.FLOAT); CLASS_TO_VALUE_WRITER.put(int.class, ValueWriter.INT); CLASS_TO_VALUE_WRITER.put(long.class, ValueWriter.LONG); CLASS_TO_VALUE_WRITER.put(Object.class, ValueWriter.OBJECT); CLASS_TO_VALUE_WRITER.put(short.class, ValueWriter.SHORT); CLASS_TO_VALUE_WRITER.put(String.class, ValueWriter.STRING); } /** * This method takes a string and outputs a JavaScript string literal. The * data is surrounded with quotes, and any contained characters that need to * be escaped are mapped onto their escape sequence. * * Assumptions: We are targeting a version of JavaScript that that is later * than 1.3 that supports unicode strings. */ public static String escapeString(String toEscape) { // make output big enough to escape every character (plus the quotes) char[] input = toEscape.toCharArray(); CharVector charVector = new CharVector(input.length * 2 + 2, input.length); charVector.add(JS_QUOTE_CHAR); for (int i = 0, n = input.length; i < n; ++i) { char c = input[i]; if (needsUnicodeEscape(c)) { unicodeEscape(c, charVector); } else { charVector.add(c); } } charVector.add(JS_QUOTE_CHAR); return String.valueOf(charVector.asArray(), 0, charVector.getSize()); } /** * Returns the {@link Class} instance to use for serialization. Enumerations * are serialized as their declaring class while all others are serialized * using their true class instance. */ private static Class<?> getClassForSerialization(Object instance) { assert (instance != null); if (instance instanceof Enum<?>) { Enum<?> e = (Enum<?>) instance; return e.getDeclaringClass(); } else { return instance.getClass(); } } /** * Returns <code>true</code> if the character requires the \\uXXXX unicode * character escape sequence. This is necessary if the raw character could be * consumed and/or interpreted as a special character when the JSON encoded * response is evaluated. For example, 0x2028 and 0x2029 are alternate line * endings for JS per ECMA-232, which are respected by Firefox and Mozilla. * <p> * Notes: * <ol> * <li>The following cases are a more conservative set of cases which are are * in the future proofing space as opposed to the required minimal set. We * could remove these and still pass our tests. * <ul> * <li>UNASSIGNED - 6359</li> * <li>NON_SPACING_MARK - 530</li> * <li>ENCLOSING_MARK - 10</li> * <li>COMBINING_SPACE_MARK - 131</li> * <li>SPACE_SEPARATOR - 19</li> * <li>CONTROL - 65</li> * <li>PRIVATE_USE - 6400</li> * <li>DASH_PUNCTUATION - 1</li> * <li>Total Characters Escaped: 13515</li> * </ul> * </li> * <li>The following cases are the minimal amount of escaping required to * prevent test failure. * <ul> * <li>LINE_SEPARATOR - 1</li> * <li>PARAGRAPH_SEPARATOR - 1</li> * <li>FORMAT - 32</li> * <li>SURROGATE - 2048</li> * <li>Total Characters Escaped: 2082</li></li> * </ul> </li> * </ol> * * @param ch character to check * @return <code>true</code> if the character requires the \\uXXXX unicode * character escape */ private static boolean needsUnicodeEscape(char ch) { switch (ch) { case ' ': // ASCII space gets caught in SPACE_SEPARATOR below, but does not // need to be escaped return false; case JS_QUOTE_CHAR: case JS_ESCAPE_CHAR: // these must be quoted or they will break the protocol return true; case NON_BREAKING_HYPHEN: // This can be expanded into a break followed by a hyphen return true; default: if (ch < ' ') { // Chrome 11 mangles control characters return true; } switch (Character.getType(ch)) { // Conservative case Character.COMBINING_SPACING_MARK: case Character.ENCLOSING_MARK: case Character.NON_SPACING_MARK: case Character.UNASSIGNED: case Character.PRIVATE_USE: case Character.SPACE_SEPARATOR: case Character.CONTROL: // Minimal case Character.LINE_SEPARATOR: case Character.FORMAT: case Character.PARAGRAPH_SEPARATOR: case Character.SURROGATE: return true; default: break; } break; } return false; } /** * Writes a safe escape sequence for a character. Some characters have a short * form, such as \n for U+000D, while others are represented as \\xNN or * \\uNNNN. * * @param ch character to unicode escape * @param charVector char vector to receive the unicode escaped representation */ private static void unicodeEscape(char ch, CharVector charVector) { charVector.add(JS_ESCAPE_CHAR); if (ch < NUMBER_OF_JS_ESCAPED_CHARS && JS_CHARS_ESCAPED[ch] != 0) { charVector.add(JS_CHARS_ESCAPED[ch]); } else if (ch < 256) { charVector.add('x'); charVector.add(NIBBLE_TO_HEX_CHAR[(ch >> 4) & 0x0F]); charVector.add(NIBBLE_TO_HEX_CHAR[ch & 0x0F]); } else { charVector.add('u'); charVector.add(NIBBLE_TO_HEX_CHAR[(ch >> 12) & 0x0F]); charVector.add(NIBBLE_TO_HEX_CHAR[(ch >> 8) & 0x0F]); charVector.add(NIBBLE_TO_HEX_CHAR[(ch >> 4) & 0x0F]); charVector.add(NIBBLE_TO_HEX_CHAR[ch & 0x0F]); } } private final SerializationPolicy serializationPolicy; private ArrayList<String> tokenList = new ArrayList<String>(); private int tokenListCharCount; public ServerSerializationStreamWriter(SerializationPolicy serializationPolicy) { this.serializationPolicy = serializationPolicy; } @Override public void prepareToWrite() { super.prepareToWrite(); tokenList.clear(); tokenListCharCount = 0; } public void serializeValue(Object value, Class<?> type) throws SerializationException { ValueWriter valueWriter = CLASS_TO_VALUE_WRITER.get(type); if (valueWriter != null) { valueWriter.write(this, value); } else { // Arrays of primitive or reference types need to go through writeObject. ValueWriter.OBJECT.write(this, value); } } /** * Build an array of JavaScript string literals that can be decoded by the * client via the eval function. * * NOTE: We build the array in reverse so the client can simply use the pop * function to remove the next item from the list. */ @Override public String toString() { // Build a JavaScript string (with escaping, of course). // We take a guess at how big to make to buffer to avoid numerous resizes. // int capacityGuess = 2 * tokenListCharCount + 2 * tokenList.size(); LengthConstrainedArray stream = new LengthConstrainedArray(capacityGuess); writePayload(stream); writeStringTable(stream); writeHeader(stream); return stream.toString(); } @Override public void writeLong(long value) { if (getVersion() == SERIALIZATION_STREAM_MIN_VERSION) { // Write longs as a pair of doubles for backwards compatibility double[] parts = getAsDoubleArray(value); assert parts != null && parts.length == 2; writeDouble(parts[0]); writeDouble(parts[1]); } else { StringBuilder sb = new StringBuilder(); sb.append('\''); sb.append(Base64Utils.toBase64(value)); sb.append('\''); append(sb.toString()); } } @Override protected void append(String token) { tokenList.add(token); if (token != null) { tokenListCharCount += token.length(); } } @Override protected String getObjectTypeSignature(Object instance) throws SerializationException { assert (instance != null); Class<?> clazz = getClassForSerialization(instance); if (hasFlags(FLAG_ELIDE_TYPE_NAMES)) { if (serializationPolicy instanceof TypeNameObfuscator) { return ((TypeNameObfuscator) serializationPolicy).getTypeIdForClass(clazz); } throw new SerializationException("The GWT module was compiled with RPC " + "type name elision enabled, but " + serializationPolicy.getClass().getName() + " does not implement " + TypeNameObfuscator.class.getName()); } else { return SerializabilityUtil.encodeSerializedInstanceReference(clazz, serializationPolicy); } } @Override protected void serialize(Object instance, String typeSignature) throws SerializationException { assert (instance != null); Class<?> clazz = getClassForSerialization(instance); try { serializationPolicy.validateSerialize(clazz); } catch (SerializationException e) { throw new SerializationException(e.getMessage() + ": instance = " + instance); } serializeImpl(instance, clazz); } /** * Serialize an instance that is an array. Will default to serializing the * instance as an Object vector if the instance is not a vector of primitives, * Strings or Object. * * @param instanceClass * @param instance * @throws SerializationException */ private void serializeArray(Class<?> instanceClass, Object instance) throws SerializationException { assert (instanceClass.isArray()); VectorWriter instanceWriter = CLASS_TO_VECTOR_WRITER.get(instanceClass); if (instanceWriter != null) { instanceWriter.write(this, instance); } else { VectorWriter.OBJECT_VECTOR.write(this, instance); } } private void serializeClass(Object instance, Class<?> instanceClass) throws SerializationException { assert (instance != null); Field[] serializableFields = SerializabilityUtil.applyFieldSerializationPolicy(instanceClass); /** * If clientFieldNames is non-null, identify any additional server-only fields and serialize * them separately. Java serialization is used to construct a byte array, which is encoded * as a String and written prior to the rest of the field data. */ Set<String> clientFieldNames = serializationPolicy.getClientFieldNamesForEnhancedClass(instanceClass); if (clientFieldNames != null) { List<Field> serverFields = new ArrayList<Field>(); for (Field declField : serializableFields) { assert (declField != null); // Identify server-only fields if (!clientFieldNames.contains(declField.getName())) { serverFields.add(declField); continue; } } // Serialize the server-only fields into a byte array and encode as a String try { ByteArrayOutputStream baos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(baos); oos.writeInt(serverFields.size()); for (Field f : serverFields) { oos.writeObject(f.getName()); f.setAccessible(true); Object fieldData = f.get(instance); oos.writeObject(fieldData); } oos.close(); byte[] serializedData = baos.toByteArray(); String encodedData = Base64Utils.toBase64(serializedData); writeString(encodedData); } catch (IllegalAccessException e) { throw new SerializationException(e); } catch (IOException e) { throw new SerializationException(e); } } // Write the client-visible field data for (Field declField : serializableFields) { if ((clientFieldNames != null) && !clientFieldNames.contains(declField.getName())) { // Skip server-only fields continue; } boolean isAccessible = declField.isAccessible(); boolean needsAccessOverride = !isAccessible && !Modifier.isPublic(declField.getModifiers()); if (needsAccessOverride) { // Override the access restrictions declField.setAccessible(true); } Object value; try { value = declField.get(instance); serializeValue(value, declField.getType()); } catch (IllegalArgumentException e) { throw new SerializationException(e); } catch (IllegalAccessException e) { throw new SerializationException(e); } } Class<?> superClass = instanceClass.getSuperclass(); if (serializationPolicy.shouldSerializeFields(superClass)) { serializeImpl(instance, superClass); } } private void serializeImpl(Object instance, Class<?> instanceClass) throws SerializationException { assert (instance != null); Class<?> customSerializer = SerializabilityUtil.hasCustomFieldSerializer(instanceClass); if (customSerializer != null) { // Use custom field serializer @SuppressWarnings("unchecked") CustomFieldSerializer<Object> customFieldSerializer = (CustomFieldSerializer<Object>) SerializabilityUtil.loadCustomFieldSerializer(customSerializer); if (customFieldSerializer == null) { serializeWithCustomSerializer(customSerializer, instance, instanceClass); } else { customFieldSerializer.serializeInstance(this, instance); } } else if (instanceClass.isArray()) { serializeArray(instanceClass, instance); } else if (instanceClass.isEnum()) { writeInt(((Enum<?>) instance).ordinal()); } else { // Regular class instance serializeClass(instance, instanceClass); } } private void serializeWithCustomSerializer(Class<?> customSerializer, Object instance, Class<?> instanceClass) throws SerializationException { try { assert (!instanceClass.isArray()); for (Method method : customSerializer.getMethods()) { if ("serialize".equals(method.getName())) { method.invoke(null, this, instance); return; } } throw new NoSuchMethodException("serialize"); } catch (SecurityException e) { throw new SerializationException(e); } catch (NoSuchMethodException e) { throw new SerializationException(e); } catch (IllegalArgumentException e) { throw new SerializationException(e); } catch (IllegalAccessException e) { throw new SerializationException(e); } catch (InvocationTargetException e) { throw new SerializationException(e); } } /** * Notice that the field are written in reverse order that the client can just * pop items out of the stream. */ private void writeHeader(LengthConstrainedArray stream) { stream.addToken(getFlags()); stream.addToken(getVersion()); } private void writePayload(LengthConstrainedArray stream) { ListIterator<String> tokenIterator = tokenList.listIterator(tokenList.size()); while (tokenIterator.hasPrevious()) { stream.addToken(tokenIterator.previous()); } } private void writeStringTable(LengthConstrainedArray stream) { LengthConstrainedArray tableStream = new LengthConstrainedArray(); for (String s : getStringTable()) { tableStream.addToken(escapeString(s)); } stream.addToken(tableStream.toString()); } }