dubbo-serialization
dubbo-serialization是dubbo中实现序列化相关的代码。
共5种序列化方式，可从名字直接看出含义，这里不再赘述。
dubbo-serialization-fastjsondubbo-serialization-fstdubbo-serialization-hessian2dubbo-serialization-jdkdubbo-serialization-kryo
dubbo-serialization-api
dubbo-serialization-api是底层实现，上述5种序列化方式均封装dubbo-serialization-api。
其中SerializableClassRegistry和SerializationOptimizer两个接口，未在源码中找到实现和引用。
Cleanable
Cleanable是供Kryo序列化方式使用，源码如下：
package org.mon.serialize;public interface Cleanable {void cleanup();}
在KryoObjectInput中实现如下：
@Overridepublic void cleanup() {KryoUtils.release(kryo);kryo = null;}
DataInput
DataInput实现了基本类型的读取。
package org.mon.serialize;
import java.io.IOException;
/**
Data input.
*/
public interface DataInput {
/**
Read boolean.@return boolean.@throws IOException
*/
boolean readBool() throws IOException;
/**
Read byte.@return byte value.@throws IOException
*/
byte readByte() throws IOException;
/**
Read short integer.@return short.@throws IOException
*/
short readShort() throws IOException;
/**
Read integer.@return integer.@throws IOException
*/
int readInt() throws IOException;
/**
Read long.@return long.@throws IOException
*/
long readLong() throws IOException;
/**
Read float.@return float.@throws IOException
*/
float readFloat() throws IOException;
/**
Read double.@return double.@throws IOException
*/
double readDouble() throws IOException;
/**
Read UTF-8 string.@return string.@throws IOException
*/
String readUTF() throws IOException;
/**
Read byte array.@return byte array.@throws IOException
*/
byte[] readBytes() throws IOException;
}
DataOutput
DataOutput实现了基本类型的写入。
package org.mon.serialize;
import java.io.IOException;
/**
Data output.
*/
public interface DataOutput {
/**
Write boolean.@param v value.@throws IOException
*/
void writeBool(boolean v) throws IOException;
/**
Write byte.@param v value.@throws IOException
*/
void writeByte(byte v) throws IOException;
/**
Write short.@param v value.@throws IOException
*/
void writeShort(short v) throws IOException;
/**
Write integer.@param v value.@throws IOException
*/
void writeInt(int v) throws IOException;
/**
Write long.@param v value.@throws IOException
*/
void writeLong(long v) throws IOException;
/**
Write float.@param v value.@throws IOException
*/
void writeFloat(float v) throws IOException;
/**
Write double.@param v value.@throws IOException
*/
void writeDouble(double v) throws IOException;
/**
Write string.@param v value.@throws IOException
*/
void writeUTF(String v) throws IOException;
/**
Write byte array.@param v value.@throws IOException
*/
void writeBytes(byte[] v) throws IOException;
/**
Write byte array.@param v value.@param off offset.@param len length.@throws IOException
*/
void writeBytes(byte[] v, int off, int len) throws IOException;
/**
Flush buffer.@throws IOException
*/
void flushBuffer() throws IOException;
}
ObjectInput
ObjectInput实现了对象的读取，继承DataInput。
package org.mon.serialize;
import java.io.IOException;
import java.lang.reflect.Type;
/**
Object input.
*/
public interface ObjectInput extends DataInput {
/**
read object.@return object.
*/
Object readObject() throws IOException, ClassNotFoundException;
/**
read object.@param cls object type.@return object.
*/
T readObject(Class cls) throws IOException, ClassNotFoundException;
/**
read object.@param cls object type.@return object.
*/
T readObject(Class cls, Type type) throws IOException, ClassNotFoundException;
}
ObjectOutput
ObjectOutput实现了对象的写入，继承DataOutput。
package org.mon.serialize;
import java.io.IOException;
/**
Object output.
*/
public interface ObjectOutput extends DataOutput {
/**
write object.@param obj object.
*/
void writeObject(Object obj) throws IOException;
}
Serialization
Serialization序列化接口。
package org.mon.serialize;
import org.mon.URL;
import org.mon.extension.Adaptive;
import org.mon.extension.SPI;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
Serialization. (SPI, Singleton, ThreadSafe)
*/
@SPI(“hessian2”)
public interface Serialization {
/**
get content type id@return content type id
*/
byte getContentTypeId();
/**
get content type@return content type
*/
String getContentType();
/**
create serializer@param url@param output@return serializer@throws IOException
*/
@Adaptive
ObjectOutput serialize(URL url, OutputStream output) throws IOException;
/**
create deserializer@param url@param input@return deserializer@throws IOException
*/
@Adaptive
ObjectInput deserialize(URL url, InputStream input) throws IOException;
}
dubbo-serialization-fastjson
用最简单的dubbo-serialization-fastjson来实例分析。
FastJsonSerialization
package org.mon.serialize.fastjson;
import org.mon.URL;
import org.mon.serialize.ObjectInput;
import org.mon.serialize.ObjectOutput;
import org.mon.serialize.Serialization;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class FastJsonSerialization implements Serialization {
@Overridepublic byte getContentTypeId() {return 6;}@Overridepublic String getContentType() {return "text/json";}// 序列化@Overridepublic ObjectOutput serialize(URL url, OutputStream output) throws IOException {// 返回FastJsonObjectOutput实例return new FastJsonObjectOutput(output);}// 反序列化@Overridepublic ObjectInput deserialize(URL url, InputStream input) throws IOException {// 返回FastJsonObjectInput实例return new FastJsonObjectInput(input);}
}
FastJsonObjectInput
FastJsonObjectInput，文件读取，主要方法如下：
@Override
public Object readObject() throws IOException, ClassNotFoundException {
String json = readLine();
return JSON.parse(json);
}
@Override@SuppressWarnings("unchecked")public <T> T readObject(Class<T> cls, Type type) throws IOException, ClassNotFoundException {Object value = readObject(cls);return (T) PojoUtils.realize(value, cls, type);}private <T> T read(Class<T> cls) throws IOException {String json = readLine();return JSON.parseObject(json, cls);}
FastJsonObjectOutput
FastJsonObjectOutput，文件写入，主要方法如下：
@Overridepublic void writeObject(Object obj) throws IOException {SerializeWriter out = new SerializeWriter();JSONSerializer serializer = new JSONSerializer(out);serializer.config(SerializerFeature.WriteEnumUsingToString, true);serializer.write(obj);out.writeTo(writer);out.close(); // for reuse SerializeWriter bufwriter.println();writer.flush();}
