//========================================================================
//Copyright 2007-2009 David Yu dyuproject@gmail.com
//------------------------------------------------------------------------
//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.dyuproject.protostuff;
import java.io.IOException;
import org.codehaus.jackson.JsonGenerator;
/**
* An output used for writing data with json format.
*
* @author David Yu
* @created Nov 20, 2009
*/
public final class JsonOutput implements Output, StatefulOutput
{
private final JsonGenerator generator;
private Schema<?> schema;
private final boolean numeric;
private boolean lastRepeated;
private int lastNumber;
public JsonOutput(JsonGenerator generator)
{
this(generator, false);
}
public JsonOutput(JsonGenerator generator, boolean numeric)
{
this.generator = generator;
this.numeric = numeric;
}
public JsonOutput(JsonGenerator generator, boolean numeric, Schema<?> schema)
{
this(generator, numeric);
this.schema = schema;
}
/**
* Resets this output for re-use.
*/
public JsonOutput reset()
{
lastRepeated = false;
lastNumber = 0;
return this;
}
/**
* Before serializing a message/object tied to a schema, this should be called.
* This also resets the internal state of this output.
*/
public JsonOutput use(Schema<?> schema)
{
this.schema = schema;
return reset();
}
/**
* Returns whether the incoming messages' field names are numeric.
*/
public boolean isNumeric()
{
return numeric;
}
/**
* Gets the last field number written.
*/
public int getLastNumber()
{
return lastNumber;
}
/**
* Returns true if the last written field was a repeated field.
*/
public boolean isLastRepeated()
{
return lastRepeated;
}
public void updateLast(Schema<?> schema, Schema<?> lastSchema)
{
if(lastSchema != null && lastSchema == this.schema)
{
this.schema = schema;
}
}
public void writeBool(int fieldNumber, boolean value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeBoolean(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeBoolean(value);
}
else
generator.writeBooleanField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeByteArray(int fieldNumber, byte[] value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeBinary(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeBinary(value);
}
else
{
generator.writeFieldName(name);
generator.writeBinary(value);
}
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeByteRange(boolean utf8String, int fieldNumber, byte[] value,
int offset, int length, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
if(utf8String)
generator.writeUTF8String(value, offset, length);
else
generator.writeBinary(value, offset, length);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
if(utf8String)
generator.writeUTF8String(value, offset, length);
else
generator.writeBinary(value, offset, length);
}
else
{
generator.writeFieldName(name);
if(utf8String)
generator.writeUTF8String(value, offset, length);
else
generator.writeBinary(value, offset, length);
}
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeBytes(int fieldNumber, ByteString value, boolean repeated) throws IOException
{
writeByteArray(fieldNumber, value.getBytes(), repeated);
}
public void writeDouble(int fieldNumber, double value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeNumber(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeNumber(value);
}
else
generator.writeNumberField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeEnum(int fieldNumber, int value, boolean repeated) throws IOException
{
writeInt32(fieldNumber, value, repeated);
}
public void writeFixed32(int fieldNumber, int value, boolean repeated) throws IOException
{
writeInt32(fieldNumber, value, repeated);
}
public void writeFixed64(int fieldNumber, long value, boolean repeated) throws IOException
{
writeInt64(fieldNumber, value, repeated);
}
public void writeFloat(int fieldNumber, float value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeNumber(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeNumber(value);
}
else
generator.writeNumberField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeInt32(int fieldNumber, int value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeNumber(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeNumber(value);
}
else
generator.writeNumberField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeInt64(int fieldNumber, long value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeNumber(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeNumber(value);
}
else
generator.writeNumberField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeSFixed32(int fieldNumber, int value, boolean repeated) throws IOException
{
writeInt32(fieldNumber, value, repeated);
}
public void writeSFixed64(int fieldNumber, long value, boolean repeated) throws IOException
{
writeInt64(fieldNumber, value, repeated);
}
public void writeSInt32(int fieldNumber, int value, boolean repeated) throws IOException
{
writeInt32(fieldNumber, value, repeated);
}
public void writeSInt64(int fieldNumber, long value, boolean repeated) throws IOException
{
writeInt64(fieldNumber, value, repeated);
}
public void writeString(int fieldNumber, String value, boolean repeated) throws IOException
{
if(lastNumber == fieldNumber)
{
// repeated field
generator.writeString(value);
return;
}
final JsonGenerator generator = this.generator;
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
schema.getFieldName(fieldNumber);
if(repeated)
{
generator.writeArrayFieldStart(name);
generator.writeString(value);
}
else
generator.writeStringField(name, value);
lastNumber = fieldNumber;
lastRepeated = repeated;
}
public void writeUInt32(int fieldNumber, int value, boolean repeated) throws IOException
{
writeInt32(fieldNumber, value, repeated);
}
public void writeUInt64(int fieldNumber, long value, boolean repeated) throws IOException
{
writeInt64(fieldNumber, value, repeated);
}
public <T> void writeObject(final int fieldNumber, final T value, final Schema<T> schema,
final boolean repeated) throws IOException
{
final JsonGenerator generator = this.generator;
final Schema<?> lastSchema = this.schema;
if(lastNumber != fieldNumber)
{
if(lastRepeated)
generator.writeEndArray();
final String name = numeric ? Integer.toString(fieldNumber) :
lastSchema.getFieldName(fieldNumber);
if(repeated)
generator.writeArrayFieldStart(name);
else
generator.writeFieldName(name);
}
// reset
this.schema = schema;
lastNumber = 0;
lastRepeated = false;
generator.writeStartObject();
// recursive write
schema.writeTo(this, value);
if(lastRepeated)
generator.writeEndArray();
generator.writeEndObject();
// restore state
lastNumber = fieldNumber;
lastRepeated = repeated;
this.schema = lastSchema;
}
}