/*
* 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.nio.ByteBuffer;
import java.util.Stack;
import org.apache.thrift.TException;
import org.apache.thrift.transport.TTransport;
/**
* JSON protocol implementation for thrift.
*
* This protocol is write-only and produces a simple output format
* suitable for parsing by scripting languages. It should not be
* confused with the full-featured TJSONProtocol.
*
*/
public class TSimpleJSONProtocol extends TProtocol {
/**
* Factory
*/
public static class Factory implements TProtocolFactory {
public TProtocol getProtocol(TTransport trans) {
return new TSimpleJSONProtocol(trans);
}
}
public static final byte[] COMMA = new byte[] {','};
public static final byte[] COLON = new byte[] {':'};
public static final byte[] LBRACE = new byte[] {'{'};
public static final byte[] RBRACE = new byte[] {'}'};
public static final byte[] LBRACKET = new byte[] {'['};
public static final byte[] RBRACKET = new byte[] {']'};
public static final char QUOTE = '"';
private static final TStruct ANONYMOUS_STRUCT = new TStruct();
private static final TField ANONYMOUS_FIELD = new TField();
private static final TMessage EMPTY_MESSAGE = new TMessage();
private static final TSet EMPTY_SET = new TSet();
private static final TList EMPTY_LIST = new TList();
private static final TMap EMPTY_MAP = new TMap();
protected class Context {
protected void write() throws TException {}
}
protected class ListContext extends Context {
protected boolean first_ = true;
protected void write() throws TException {
if (first_) {
first_ = false;
} else {
trans_.write(COMMA);
}
}
}
protected class StructContext extends Context {
protected boolean first_ = true;
protected boolean colon_ = true;
protected void write() throws TException {
if (first_) {
first_ = false;
colon_ = true;
} else {
trans_.write(colon_ ? COLON : COMMA);
colon_ = !colon_;
}
}
}
protected final Context BASE_CONTEXT = new Context();
/**
* Stack of nested contexts that we may be in.
*/
protected Stack<Context> writeContextStack_ = new Stack<Context>();
/**
* Current context that we are in
*/
protected Context writeContext_ = BASE_CONTEXT;
/**
* Push a new write context onto the stack.
*/
protected void pushWriteContext(Context c) {
writeContextStack_.push(writeContext_);
writeContext_ = c;
}
/**
* Pop the last write context off the stack
*/
protected void popWriteContext() {
writeContext_ = writeContextStack_.pop();
}
/**
* Constructor
*/
public TSimpleJSONProtocol(TTransport trans) {
super(trans);
}
public void writeMessageBegin(TMessage message) throws TException {
trans_.write(LBRACKET);
pushWriteContext(new ListContext());
writeString(message.name);
writeByte(message.type);
writeI32(message.seqid);
}
public void writeMessageEnd() throws TException {
popWriteContext();
trans_.write(RBRACKET);
}
public void writeStructBegin(TStruct struct) throws TException {
writeContext_.write();
trans_.write(LBRACE);
pushWriteContext(new StructContext());
}
public void writeStructEnd() throws TException {
popWriteContext();
trans_.write(RBRACE);
}
public void writeFieldBegin(TField field) throws TException {
// Note that extra type information is omitted in JSON!
writeString(field.name);
}
public void writeFieldEnd() {}
public void writeFieldStop() {}
public void writeMapBegin(TMap map) throws TException {
writeContext_.write();
trans_.write(LBRACE);
pushWriteContext(new StructContext());
// No metadata!
}
public void writeMapEnd() throws TException {
popWriteContext();
trans_.write(RBRACE);
}
public void writeListBegin(TList list) throws TException {
writeContext_.write();
trans_.write(LBRACKET);
pushWriteContext(new ListContext());
// No metadata!
}
public void writeListEnd() throws TException {
popWriteContext();
trans_.write(RBRACKET);
}
public void writeSetBegin(TSet set) throws TException {
writeContext_.write();
trans_.write(LBRACKET);
pushWriteContext(new ListContext());
// No metadata!
}
public void writeSetEnd() throws TException {
popWriteContext();
trans_.write(RBRACKET);
}
public void writeBool(boolean b) throws TException {
writeByte(b ? (byte)1 : (byte)0);
}
public void writeByte(byte b) throws TException {
writeI32(b);
}
public void writeI16(short i16) throws TException {
writeI32(i16);
}
public void writeI32(int i32) throws TException {
writeContext_.write();
_writeStringData(Integer.toString(i32));
}
public void _writeStringData(String s) throws TException {
try {
byte[] b = s.getBytes("UTF-8");
trans_.write(b);
} catch (UnsupportedEncodingException uex) {
throw new TException("JVM DOES NOT SUPPORT UTF-8");
}
}
public void writeI64(long i64) throws TException {
writeContext_.write();
_writeStringData(Long.toString(i64));
}
public void writeDouble(double dub) throws TException {
writeContext_.write();
_writeStringData(Double.toString(dub));
}
public void writeString(String str) throws TException {
writeContext_.write();
int length = str.length();
StringBuffer escape = new StringBuffer(length + 16);
escape.append(QUOTE);
for (int i = 0; i < length; ++i) {
char c = str.charAt(i);
switch (c) {
case '"':
case '\\':
escape.append('\\');
escape.append(c);
break;
case '\b':
escape.append('\\');
escape.append('b');
break;
case '\f':
escape.append('\\');
escape.append('f');
break;
case '\n':
escape.append('\\');
escape.append('n');
break;
case '\r':
escape.append('\\');
escape.append('r');
break;
case '\t':
escape.append('\\');
escape.append('t');
break;
default:
// Control characters! According to JSON RFC u0020 (space)
if (c < ' ') {
String hex = Integer.toHexString(c);
escape.append('\\');
escape.append('u');
for (int j = 4; j > hex.length(); --j) {
escape.append('0');
}
escape.append(hex);
} else {
escape.append(c);
}
break;
}
}
escape.append(QUOTE);
_writeStringData(escape.toString());
}
public void writeBinary(ByteBuffer bin) throws TException {
try {
// TODO(mcslee): Fix this
writeString(new String(bin.array(), bin.position() + bin.arrayOffset(), bin.limit() - bin.position() - bin.arrayOffset(), "UTF-8"));
} catch (UnsupportedEncodingException uex) {
throw new TException("JVM DOES NOT SUPPORT UTF-8");
}
}
/**
* Reading methods.
*/
public TMessage readMessageBegin() throws TException {
// TODO(mcslee): implement
return EMPTY_MESSAGE;
}
public void readMessageEnd() {}
public TStruct readStructBegin() {
// TODO(mcslee): implement
return ANONYMOUS_STRUCT;
}
public void readStructEnd() {}
public TField readFieldBegin() throws TException {
// TODO(mcslee): implement
return ANONYMOUS_FIELD;
}
public void readFieldEnd() {}
public TMap readMapBegin() throws TException {
// TODO(mcslee): implement
return EMPTY_MAP;
}
public void readMapEnd() {}
public TList readListBegin() throws TException {
// TODO(mcslee): implement
return EMPTY_LIST;
}
public void readListEnd() {}
public TSet readSetBegin() throws TException {
// TODO(mcslee): implement
return EMPTY_SET;
}
public void readSetEnd() {}
public boolean readBool() throws TException {
return (readByte() == 1);
}
public byte readByte() throws TException {
// TODO(mcslee): implement
return 0;
}
public short readI16() throws TException {
// TODO(mcslee): implement
return 0;
}
public int readI32() throws TException {
// TODO(mcslee): implement
return 0;
}
public long readI64() throws TException {
// TODO(mcslee): implement
return 0;
}
public double readDouble() throws TException {
// TODO(mcslee): implement
return 0;
}
public String readString() throws TException {
// TODO(mcslee): implement
return "";
}
public String readStringBody(int size) throws TException {
// TODO(mcslee): implement
return "";
}
public ByteBuffer readBinary() throws TException {
// TODO(mcslee): implement
return ByteBuffer.wrap(new byte[0]);
}
}