THRIFT-2250 JSON and MemoryBuffer for JavaME

Patch: Henrique Mendonca

2 files changed, 985 insertions, 0 deletions

diff --git a/lib/javame/src/org/apache/thrift/protocol/TJSONProtocol.java b/lib/javame/src/org/apache/thrift/protocol/TJSONProtocol.java
new file mode 100644
index 000000000..fd92d453e
--- /dev/null
+++ b/lib/javame/src/org/apache/thrift/protocol/TJSONProtocol.java
@@ -0,0 +1,888 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 org.apache.thrift.protocol;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Stack;
+
+import org.apache.thrift.TByteArrayOutputStream;
+import org.apache.thrift.TException;
+import org.apache.thrift.transport.TTransport;
+
+/**
+ * JSON protocol implementation for thrift.
+ * This is a full-featured protocol supporting write and read.
+ * Please see the C++ class header for a detailed description of the
+ * protocol's wire format.
+ */
+public class TJSONProtocol extends TProtocol {
+
+  /**
+   * Factory for JSON protocol objects
+   */
+  public static class Factory implements TProtocolFactory {
+
+    public TProtocol getProtocol(TTransport trans) {
+      return new TJSONProtocol(trans);
+    }
+
+  }
+
+  private static final byte[]  COMMA            = new byte[] { ',' };
+  private static final byte[]  COLON            = new byte[] { ':' };
+  private static final byte[]  LBRACE           = new byte[] { '{' };
+  private static final byte[]  RBRACE           = new byte[] { '}' };
+  private static final byte[]  LBRACKET         = new byte[] { '[' };
+  private static final byte[]  RBRACKET         = new byte[] { ']' };
+  private static final byte[]  QUOTE            = new byte[] { '"' };
+  private static final byte[]  BACKSLASH        = new byte[] { '\\' };
+  private static final byte[]  ZERO             = new byte[] { '0' };
+
+  private static final byte[]  ESCSEQ           = new byte[] { '\\', 'u', '0', '0' };
+
+  private static final long    VERSION          = 1;
+
+  private static final byte[]  JSON_CHAR_TABLE  = {
+                                                /* 0 1 2 3 4 5 6 7 8 9 A B C D E F */
+                                                0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0, // 0
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1
+      1, 1, '"', 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 2
+                                                };
+
+  private static final String  ESCAPE_CHARS     = "\"\\bfnrt";
+
+  private static final byte[]  ESCAPE_CHAR_VALS = {
+                                                '"', '\\', '\b', '\f', '\n', '\r', '\t',
+                                                };
+
+  private static final int     DEF_STRING_SIZE  = 16;
+
+  private static final byte[]  NAME_BOOL        = new byte[] { 't', 'f' };
+  private static final byte[]  NAME_BYTE        = new byte[] { 'i', '8' };
+  private static final byte[]  NAME_I16         = new byte[] { 'i', '1', '6' };
+  private static final byte[]  NAME_I32         = new byte[] { 'i', '3', '2' };
+  private static final byte[]  NAME_I64         = new byte[] { 'i', '6', '4' };
+  private static final byte[]  NAME_DOUBLE      = new byte[] { 'd', 'b', 'l' };
+  private static final byte[]  NAME_STRUCT      = new byte[] { 'r', 'e', 'c' };
+  private static final byte[]  NAME_STRING      = new byte[] { 's', 't', 'r' };
+  private static final byte[]  NAME_MAP         = new byte[] { 'm', 'a', 'p' };
+  private static final byte[]  NAME_LIST        = new byte[] { 'l', 's', 't' };
+  private static final byte[]  NAME_SET         = new byte[] { 's', 'e', 't' };
+
+  private static final TStruct ANONYMOUS_STRUCT = new TStruct();
+
+  private static final byte[] getTypeNameForTypeID(byte typeID)
+                                                               throws TException {
+    switch (typeID) {
+    case TType.BOOL:
+      return NAME_BOOL;
+    case TType.BYTE:
+      return NAME_BYTE;
+    case TType.I16:
+      return NAME_I16;
+    case TType.I32:
+      return NAME_I32;
+    case TType.I64:
+      return NAME_I64;
+    case TType.DOUBLE:
+      return NAME_DOUBLE;
+    case TType.STRING:
+      return NAME_STRING;
+    case TType.STRUCT:
+      return NAME_STRUCT;
+    case TType.MAP:
+      return NAME_MAP;
+    case TType.SET:
+      return NAME_SET;
+    case TType.LIST:
+      return NAME_LIST;
+    default:
+      throw new TProtocolException(TProtocolException.NOT_IMPLEMENTED,
+          "Unrecognized type");
+    }
+  }
+
+  private static final byte getTypeIDForTypeName(byte[] name)
+                                                             throws TException {
+    byte result = TType.STOP;
+    if (name.length > 1) {
+      switch (name[0]) {
+      case 'd':
+        result = TType.DOUBLE;
+        break;
+      case 'i':
+        switch (name[1]) {
+        case '8':
+          result = TType.BYTE;
+          break;
+        case '1':
+          result = TType.I16;
+          break;
+        case '3':
+          result = TType.I32;
+          break;
+        case '6':
+          result = TType.I64;
+          break;
+        }
+        break;
+      case 'l':
+        result = TType.LIST;
+        break;
+      case 'm':
+        result = TType.MAP;
+        break;
+      case 'r':
+        result = TType.STRUCT;
+        break;
+      case 's':
+        if (name[1] == 't') {
+          result = TType.STRING;
+        }
+        else if (name[1] == 'e') {
+          result = TType.SET;
+        }
+        break;
+      case 't':
+        result = TType.BOOL;
+        break;
+      }
+    }
+    if (result == TType.STOP) {
+      throw new TProtocolException(TProtocolException.NOT_IMPLEMENTED,
+          "Unrecognized type");
+    }
+    return result;
+  }
+
+  // Base class for tracking JSON contexts that may require inserting/reading
+  // additional JSON syntax characters
+  // This base context does nothing.
+  protected class JSONBaseContext {
+    /**
+     * @throws TException
+     */
+    protected void write() throws TException {}
+
+    /**
+     * @throws TException
+     */
+    protected void read() throws TException {}
+
+    protected boolean escapeNum() {
+      return false;
+    }
+  }
+
+  // Context for JSON lists. Will insert/read commas before each item except
+  // for the first one
+  protected class JSONListContext extends JSONBaseContext {
+    private boolean first_ = true;
+
+    protected void write() throws TException {
+      if (first_) {
+        first_ = false;
+      } else {
+        trans_.write(COMMA);
+      }
+    }
+
+    protected void read() throws TException {
+      if (first_) {
+        first_ = false;
+      } else {
+        readJSONSyntaxChar(COMMA);
+      }
+    }
+  }
+
+  // Context for JSON records. Will insert/read colons before the value portion
+  // of each record pair, and commas before each key except the first. In
+  // addition, will indicate that numbers in the key position need to be
+  // escaped in quotes (since JSON keys must be strings).
+  protected class JSONPairContext extends JSONBaseContext {
+    private boolean first_ = true;
+    private boolean colon_ = true;
+
+    protected void write() throws TException {
+      if (first_) {
+        first_ = false;
+        colon_ = true;
+      } else {
+        trans_.write(colon_ ? COLON : COMMA);
+        colon_ = !colon_;
+      }
+    }
+
+    protected void read() throws TException {
+      if (first_) {
+        first_ = false;
+        colon_ = true;
+      } else {
+        readJSONSyntaxChar(colon_ ? COLON : COMMA);
+        colon_ = !colon_;
+      }
+    }
+
+    protected boolean escapeNum() {
+      return colon_;
+    }
+  }
+
+  // Holds up to one byte from the transport
+  protected class LookaheadReader {
+
+    private boolean hasData_;
+    private byte[]  data_ = new byte[1];
+
+    // Return and consume the next byte to be read, either taking it from the
+    // data buffer if present or getting it from the transport otherwise.
+    protected byte read() throws TException {
+      if (hasData_) {
+        hasData_ = false;
+      }
+      else {
+        trans_.readAll(data_, 0, 1);
+      }
+      return data_[0];
+    }
+
+    // Return the next byte to be read without consuming, filling the data
+    // buffer if it has not been filled already.
+    protected byte peek() throws TException {
+      if (!hasData_) {
+        trans_.readAll(data_, 0, 1);
+      }
+      hasData_ = true;
+      return data_[0];
+    }
+  }
+
+  // Stack of nested contexts of type JSONBaseContext that we may be in
+  private Stack           contextStack_ = new Stack();
+
+  // Current context that we are in
+  private JSONBaseContext context_      = new JSONBaseContext();
+
+  // Reader that manages a 1-byte buffer
+  private LookaheadReader reader_       = new LookaheadReader();
+
+  // Push a new JSON context onto the stack.
+  private void pushContext(JSONBaseContext c) {
+    contextStack_.push(context_);
+    context_ = c;
+  }
+
+  // Pop the last JSON context off the stack
+  private void popContext() {
+    context_ = (JSONBaseContext)contextStack_.pop();
+  }
+
+  /**
+   * Constructor
+   */
+  public TJSONProtocol(TTransport trans) {
+    super(trans);
+  }
+
+  public void reset() {
+    contextStack_.clear();
+    context_ = new JSONBaseContext();
+    reader_ = new LookaheadReader();
+  }
+
+  // Temporary buffer used by several methods
+  private byte[] tmpbuf_ = new byte[4];
+
+  // Read a byte that must match b[0]; otherwise an exception is thrown.
+  // Marked protected to avoid synthetic accessor in JSONListContext.read
+  // and JSONPairContext.read
+  protected void readJSONSyntaxChar(byte[] b) throws TException {
+    byte ch = reader_.read();
+    if (ch != b[0]) {
+      throw new TProtocolException(TProtocolException.INVALID_DATA,
+          "Unexpected character:" + (char)ch);
+    }
+  }
+
+  // Convert a byte containing a hex char ('0'-'9' or 'a'-'f') into its
+  // corresponding hex value
+  private static final byte hexVal(byte ch) throws TException {
+    if ((ch >= '0') && (ch <= '9')) {
+      return (byte)((char)ch - '0');
+    }
+    else if ((ch >= 'a') && (ch <= 'f')) {
+      return (byte)((char)ch - 'a' + 10);
+    }
+    else {
+      throw new TProtocolException(TProtocolException.INVALID_DATA,
+          "Expected hex character");
+    }
+  }
+
+  // Convert a byte containing a hex value to its corresponding hex character
+  private static final byte hexChar(byte val) {
+    val &= 0x0F;
+    if (val < 10) {
+      return (byte)((char)val + '0');
+    }
+    else {
+      return (byte)((char)(val - 10) + 'a');
+    }
+  }
+
+  // Write the bytes in array buf as a JSON characters, escaping as needed
+  private void writeJSONString(byte[] b) throws TException {
+    context_.write();
+    trans_.write(QUOTE);
+    int len = b.length;
+    for (int i = 0; i < len; i++) {
+      if ((b[i] & 0x00FF) >= 0x30) {
+        if (b[i] == BACKSLASH[0]) {
+          trans_.write(BACKSLASH);
+          trans_.write(BACKSLASH);
+        }
+        else {
+          trans_.write(b, i, 1);
+        }
+      }
+      else {
+        tmpbuf_[0] = JSON_CHAR_TABLE[b[i]];
+        if (tmpbuf_[0] == 1) {
+          trans_.write(b, i, 1);
+        }
+        else if (tmpbuf_[0] > 1) {
+          trans_.write(BACKSLASH);
+          trans_.write(tmpbuf_, 0, 1);
+        }
+        else {
+          trans_.write(ESCSEQ);
+          tmpbuf_[0] = hexChar((byte)(b[i] >> 4));
+          tmpbuf_[1] = hexChar(b[i]);
+          trans_.write(tmpbuf_, 0, 2);
+        }
+      }
+    }
+    trans_.write(QUOTE);
+  }
+
+  // Write out number as a JSON value. If the context dictates so, it will be
+  // wrapped in quotes to output as a JSON string.
+  private void writeJSONInteger(long num) throws TException {
+    context_.write();
+    String str = Long.toString(num);
+    boolean escapeNum = context_.escapeNum();
+    if (escapeNum) {
+      trans_.write(QUOTE);
+    }
+    try {
+      byte[] buf = str.getBytes("UTF-8");
+      trans_.write(buf);
+    } catch (UnsupportedEncodingException uex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+    if (escapeNum) {
+      trans_.write(QUOTE);
+    }
+  }
+
+  // Write out a double as a JSON value. If it is NaN or infinity or if the
+  // context dictates escaping, write out as JSON string.
+  private void writeJSONDouble(double num) throws TException {
+    context_.write();
+    String str = Double.toString(num);
+    boolean special = false;
+    switch (str.charAt(0)) {
+    case 'N': // NaN
+    case 'I': // Infinity
+      special = true;
+      break;
+    case '-':
+      if (str.charAt(1) == 'I') { // -Infinity
+        special = true;
+      }
+      break;
+    }
+
+    boolean escapeNum = special || context_.escapeNum();
+    if (escapeNum) {
+      trans_.write(QUOTE);
+    }
+    try {
+      byte[] b = str.getBytes("UTF-8");
+      trans_.write(b, 0, b.length);
+    } catch (UnsupportedEncodingException uex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+    if (escapeNum) {
+      trans_.write(QUOTE);
+    }
+  }
+
+  // Write out contents of byte array b as a JSON string with base-64 encoded
+  // data
+  private void writeJSONBase64(byte[] b, int offset, int length) throws TException {
+    context_.write();
+    trans_.write(QUOTE);
+    int len = length;
+    int off = offset;
+    while (len >= 3) {
+      // Encode 3 bytes at a time
+      TBase64Utils.encode(b, off, 3, tmpbuf_, 0);
+      trans_.write(tmpbuf_, 0, 4);
+      off += 3;
+      len -= 3;
+    }
+    if (len > 0) {
+      // Encode remainder
+      TBase64Utils.encode(b, off, len, tmpbuf_, 0);
+      trans_.write(tmpbuf_, 0, len + 1);
+    }
+    trans_.write(QUOTE);
+  }
+
+  private void writeJSONObjectStart() throws TException {
+    context_.write();
+    trans_.write(LBRACE);
+    pushContext(new JSONPairContext());
+  }
+
+  private void writeJSONObjectEnd() throws TException {
+    popContext();
+    trans_.write(RBRACE);
+  }
+
+  private void writeJSONArrayStart() throws TException {
+    context_.write();
+    trans_.write(LBRACKET);
+    pushContext(new JSONListContext());
+  }
+
+  private void writeJSONArrayEnd() throws TException {
+    popContext();
+    trans_.write(RBRACKET);
+  }
+
+  public void writeMessageBegin(TMessage message) throws TException {
+    writeJSONArrayStart();
+    writeJSONInteger(VERSION);
+    try {
+      byte[] b = message.name.getBytes("UTF-8");
+      writeJSONString(b);
+    } catch (UnsupportedEncodingException uex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+    writeJSONInteger(message.type);
+    writeJSONInteger(message.seqid);
+  }
+
+  public void writeMessageEnd() throws TException {
+    writeJSONArrayEnd();
+  }
+
+  public void writeStructBegin(TStruct struct) throws TException {
+    writeJSONObjectStart();
+  }
+
+  public void writeStructEnd() throws TException {
+    writeJSONObjectEnd();
+  }
+
+  public void writeFieldBegin(TField field) throws TException {
+    writeJSONInteger(field.id);
+    writeJSONObjectStart();
+    writeJSONString(getTypeNameForTypeID(field.type));
+  }
+
+  public void writeFieldEnd() throws TException {
+    writeJSONObjectEnd();
+  }
+
+  public void writeFieldStop() {}
+
+  public void writeMapBegin(TMap map) throws TException {
+    writeJSONArrayStart();
+    writeJSONString(getTypeNameForTypeID(map.keyType));
+    writeJSONString(getTypeNameForTypeID(map.valueType));
+    writeJSONInteger(map.size);
+    writeJSONObjectStart();
+  }
+
+  public void writeMapEnd() throws TException {
+    writeJSONObjectEnd();
+    writeJSONArrayEnd();
+  }
+
+  public void writeListBegin(TList list) throws TException {
+    writeJSONArrayStart();
+    writeJSONString(getTypeNameForTypeID(list.elemType));
+    writeJSONInteger(list.size);
+  }
+
+  public void writeListEnd() throws TException {
+    writeJSONArrayEnd();
+  }
+
+  public void writeSetBegin(TSet set) throws TException {
+    writeJSONArrayStart();
+    writeJSONString(getTypeNameForTypeID(set.elemType));
+    writeJSONInteger(set.size);
+  }
+
+  public void writeSetEnd() throws TException {
+    writeJSONArrayEnd();
+  }
+
+  public void writeBool(boolean b) throws TException {
+    writeJSONInteger(b ? (long)1 : (long)0);
+  }
+
+  public void writeByte(byte b) throws TException {
+    writeJSONInteger(b);
+  }
+
+  public void writeI16(short i16) throws TException {
+    writeJSONInteger(i16);
+  }
+
+  public void writeI32(int i32) throws TException {
+    writeJSONInteger(i32);
+  }
+
+  public void writeI64(long i64) throws TException {
+    writeJSONInteger(i64);
+  }
+
+  public void writeDouble(double dub) throws TException {
+    writeJSONDouble(dub);
+  }
+
+  public void writeString(String str) throws TException {
+    try {
+      byte[] b = str.getBytes("UTF-8");
+      writeJSONString(b);
+    } catch (UnsupportedEncodingException uex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+  }
+
+  public void writeBinary(byte[] bin) throws TException {
+    writeJSONBase64(bin, 0, bin.length);
+  }
+
+  /**
+   * Reading methods.
+   */
+
+  // Read in a JSON string, unescaping as appropriate.. Skip reading from the
+  // context if skipContext is true.
+  private TByteArrayOutputStream readJSONString(boolean skipContext)
+                                                                    throws TException {
+    TByteArrayOutputStream arr = new TByteArrayOutputStream(DEF_STRING_SIZE);
+    if (!skipContext) {
+      context_.read();
+    }
+    readJSONSyntaxChar(QUOTE);
+    while (true) {
+      byte ch = reader_.read();
+      if (ch == QUOTE[0]) {
+        break;
+      }
+      if (ch == ESCSEQ[0]) {
+        ch = reader_.read();
+        if (ch == ESCSEQ[1]) {
+          readJSONSyntaxChar(ZERO);
+          readJSONSyntaxChar(ZERO);
+          trans_.readAll(tmpbuf_, 0, 2);
+          ch = (byte)((hexVal(tmpbuf_[0]) << 4) + hexVal(tmpbuf_[1]));
+        }
+        else {
+          int off = ESCAPE_CHARS.indexOf(ch);
+          if (off == -1) {
+            throw new TProtocolException(TProtocolException.INVALID_DATA,
+                "Expected control char");
+          }
+          ch = ESCAPE_CHAR_VALS[off];
+        }
+      }
+      arr.write(ch);
+    }
+    return arr;
+  }
+
+  // Return true if the given byte could be a valid part of a JSON number.
+  private boolean isJSONNumeric(byte b) {
+    switch (b) {
+    case '+':
+    case '-':
+    case '.':
+    case '0':
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+    case 'E':
+    case 'e':
+      return true;
+    }
+    return false;
+  }
+
+  // Read in a sequence of characters that are all valid in JSON numbers. Does
+  // not do a complete regex check to validate that this is actually a number.
+  private String readJSONNumericChars() throws TException {
+    StringBuffer strbuf = new StringBuffer();
+    while (true) {
+      byte ch = reader_.peek();
+      if (!isJSONNumeric(ch)) {
+        break;
+      }
+      strbuf.append((char)reader_.read());
+    }
+    return strbuf.toString();
+  }
+
+  // Read in a JSON number. If the context dictates, read in enclosing quotes.
+  private long readJSONInteger() throws TException {
+    context_.read();
+    if (context_.escapeNum()) {
+      readJSONSyntaxChar(QUOTE);
+    }
+    String str = readJSONNumericChars();
+    if (context_.escapeNum()) {
+      readJSONSyntaxChar(QUOTE);
+    }
+    try {
+      return Long.valueOf(str).longValue();
+    } catch (NumberFormatException ex) {
+      throw new TProtocolException(TProtocolException.INVALID_DATA,
+          "Bad data encounted in numeric data");
+    }
+  }
+
+  // Read in a JSON double value. Throw if the value is not wrapped in quotes
+  // when expected or if wrapped in quotes when not expected.
+  private double readJSONDouble() throws TException {
+    context_.read();
+    if (reader_.peek() == QUOTE[0]) {
+      TByteArrayOutputStream arr = readJSONString(true);
+      try {
+        double dub = Double.valueOf(arr.toString("UTF-8")).doubleValue();
+        if (!context_.escapeNum() && !Double.isNaN(dub) &&
+            !Double.isInfinite(dub)) {
+          // Throw exception -- we should not be in a string in this case
+          throw new TProtocolException(TProtocolException.INVALID_DATA,
+              "Numeric data unexpectedly quoted");
+        }
+        return dub;
+      } catch (UnsupportedEncodingException ex) {
+        throw new TException("JVM DOES NOT SUPPORT UTF-8");
+      }
+    }
+    else {
+      if (context_.escapeNum()) {
+        // This will throw - we should have had a quote if escapeNum == true
+        readJSONSyntaxChar(QUOTE);
+      }
+      try {
+        return Double.valueOf(readJSONNumericChars()).doubleValue();
+      } catch (NumberFormatException ex) {
+        throw new TProtocolException(TProtocolException.INVALID_DATA,
+            "Bad data encounted in numeric data");
+      }
+    }
+  }
+
+  // Read in a JSON string containing base-64 encoded data and decode it.
+  private byte[] readJSONBase64() throws TException {
+    TByteArrayOutputStream arr = readJSONString(false);
+    byte[] b = arr.get();
+    int len = arr.len();
+    int off = 0;
+    int size = 0;
+    while (len >= 4) {
+      // Decode 4 bytes at a time
+      TBase64Utils.decode(b, off, 4, b, size); // NB: decoded in place
+      off += 4;
+      len -= 4;
+      size += 3;
+    }
+    // Don't decode if we hit the end or got a single leftover byte (invalid
+    // base64 but legal for skip of regular string type)
+    if (len > 1) {
+      // Decode remainder
+      TBase64Utils.decode(b, off, len, b, size); // NB: decoded in place
+      size += len - 1;
+    }
+    // Sadly we must copy the byte[] (any way around this?)
+    byte[] result = new byte[size];
+    System.arraycopy(b, 0, result, 0, size);
+    return result;
+  }
+
+  private void readJSONObjectStart() throws TException {
+    context_.read();
+    readJSONSyntaxChar(LBRACE);
+    pushContext(new JSONPairContext());
+  }
+
+  private void readJSONObjectEnd() throws TException {
+    readJSONSyntaxChar(RBRACE);
+    popContext();
+  }
+
+  private void readJSONArrayStart() throws TException {
+    context_.read();
+    readJSONSyntaxChar(LBRACKET);
+    pushContext(new JSONListContext());
+  }
+
+  private void readJSONArrayEnd() throws TException {
+    readJSONSyntaxChar(RBRACKET);
+    popContext();
+  }
+
+  public TMessage readMessageBegin() throws TException {
+    readJSONArrayStart();
+    if (readJSONInteger() != VERSION) {
+      throw new TProtocolException(TProtocolException.BAD_VERSION,
+          "Message contained bad version.");
+    }
+    String name;
+    try {
+      name = readJSONString(false).toString("UTF-8");
+    } catch (UnsupportedEncodingException ex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+    byte type = (byte)readJSONInteger();
+    int seqid = (int)readJSONInteger();
+    return new TMessage(name, type, seqid);
+  }
+
+  public void readMessageEnd() throws TException {
+    readJSONArrayEnd();
+  }
+
+  public TStruct readStructBegin() throws TException {
+    readJSONObjectStart();
+    return ANONYMOUS_STRUCT;
+  }
+
+  public void readStructEnd() throws TException {
+    readJSONObjectEnd();
+  }
+
+  public TField readFieldBegin() throws TException {
+    byte ch = reader_.peek();
+    byte type;
+    short id = 0;
+    if (ch == RBRACE[0]) {
+      type = TType.STOP;
+    }
+    else {
+      id = (short)readJSONInteger();
+      readJSONObjectStart();
+      type = getTypeIDForTypeName(readJSONString(false).get());
+    }
+    return new TField("", type, id);
+  }
+
+  public void readFieldEnd() throws TException {
+    readJSONObjectEnd();
+  }
+
+  public TMap readMapBegin() throws TException {
+    readJSONArrayStart();
+    byte keyType = getTypeIDForTypeName(readJSONString(false).get());
+    byte valueType = getTypeIDForTypeName(readJSONString(false).get());
+    int size = (int)readJSONInteger();
+    readJSONObjectStart();
+    return new TMap(keyType, valueType, size);
+  }
+
+  public void readMapEnd() throws TException {
+    readJSONObjectEnd();
+    readJSONArrayEnd();
+  }
+
+  public TList readListBegin() throws TException {
+    readJSONArrayStart();
+    byte elemType = getTypeIDForTypeName(readJSONString(false).get());
+    int size = (int)readJSONInteger();
+    return new TList(elemType, size);
+  }
+
+  public void readListEnd() throws TException {
+    readJSONArrayEnd();
+  }
+
+  public TSet readSetBegin() throws TException {
+    readJSONArrayStart();
+    byte elemType = getTypeIDForTypeName(readJSONString(false).get());
+    int size = (int)readJSONInteger();
+    return new TSet(elemType, size);
+  }
+
+  public void readSetEnd() throws TException {
+    readJSONArrayEnd();
+  }
+
+  public boolean readBool() throws TException {
+    return (readJSONInteger() == 0 ? false : true);
+  }
+
+  public byte readByte() throws TException {
+    return (byte)readJSONInteger();
+  }
+
+  public short readI16() throws TException {
+    return (short)readJSONInteger();
+  }
+
+  public int readI32() throws TException {
+    return (int)readJSONInteger();
+  }
+
+  public long readI64() throws TException {
+    return readJSONInteger();
+  }
+
+  public double readDouble() throws TException {
+    return readJSONDouble();
+  }
+
+  public String readString() throws TException {
+    try {
+      return readJSONString(false).toString("UTF-8");
+    } catch (UnsupportedEncodingException ex) {
+      throw new TException("JVM DOES NOT SUPPORT UTF-8");
+    }
+  }
+
+  public byte[] readBinary() throws TException {
+    return readJSONBase64();
+  }
+
+}
diff --git a/lib/javame/src/org/apache/thrift/transport/TMemoryBuffer.java b/lib/javame/src/org/apache/thrift/transport/TMemoryBuffer.java
new file mode 100644
index 000000000..4ae1ab242
--- /dev/null
+++ b/lib/javame/src/org/apache/thrift/transport/TMemoryBuffer.java
@@ -0,0 +1,97 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 org.apache.thrift.transport;
+
+import org.apache.thrift.TByteArrayOutputStream;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Memory buffer-based implementation of the TTransport interface.
+ */
+public class TMemoryBuffer extends TTransport {
+  /**
+   * Create a TMemoryBuffer with an initial buffer size of <i>size</i>. The
+   * internal buffer will grow as necessary to accommodate the size of the data
+   * being written to it.
+   */
+  public TMemoryBuffer(int size) {
+    arr_ = new TByteArrayOutputStream(size);
+  }
+
+  public boolean isOpen() {
+    return true;
+  }
+
+  public void open() {
+    /* Do nothing */
+  }
+
+  public void close() {
+    /* Do nothing */
+  }
+
+  public int read(byte[] buf, int off, int len) {
+    byte[] src = arr_.get();
+    int amtToRead = (len > arr_.len() - pos_ ? arr_.len() - pos_ : len);
+    if (amtToRead > 0) {
+      System.arraycopy(src, pos_, buf, off, amtToRead);
+      pos_ += amtToRead;
+    }
+    return amtToRead;
+  }
+
+  public void write(byte[] buf, int off, int len) {
+    arr_.write(buf, off, len);
+  }
+
+  /**
+   * Output the contents of the memory buffer as a String, using the supplied
+   * encoding
+   * 
+   * @param enc the encoding to use
+   * @return the contents of the memory buffer as a String
+   */
+  public String toString(String enc) throws UnsupportedEncodingException {
+    return arr_.toString(enc);
+  }
+
+  public String inspect() {
+    String buf = "";
+    byte[] bytes = arr_.toByteArray();
+    for (int i = 0; i < bytes.length; i++) {
+      buf += (pos_ == i ? "==>" : "") + Integer.toHexString(bytes[i] & 0xff) + " ";
+    }
+    return buf;
+  }
+
+  // The contents of the buffer
+  private TByteArrayOutputStream arr_;
+
+  // Position to read next byte from
+  private int                    pos_;
+
+  public int length() {
+    return arr_.size();
+  }
+
+  public byte[] getArray() {
+    return arr_.get();
+  }
+}