Netty自定义序列化协议

谁践踏了优雅 2021-12-14 12:03 370阅读 0赞

## 自定义序列化协议 ##

**序列化的目的就是想对象转化成字节数组byteArray**

**阶段一**  
使用流的形式

public class Test{
    public static void main(String[] args) throws IOException {
    		int id = 100;
    		int age = 22;
    		ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
    		arrayOutputStream.write(int2bytes(id));//序列化
    		arrayOutputStream.write(int2bytes(age));	
    		byte[] byteArray = arrayOutputStream.toByteArray();
    		//==================通过socket传输字节序列=================================
    		ByteArrayInputStream arrayInputStream = new ByteArrayInputStream(byteArray);
    		byte[] idBytes = new byte[4];//读取4个字节
    		arrayInputStream.read(idBytes);
    	        System.out.println("id:" + bytes2int(idBytes));//反序列化
    		byte[] ageBytes = new byte[4];
    		arrayInputStream.read(ageBytes);
    		System.out.println("age:" + bytes2int(ageBytes));		
    	}
    	
    /*
    * int 类型占4个字节  采用大端字节序列（高位在前面）
    */
    //序列化
    public static byte[] int2byte(int i)
    {
        byte[]bytes =new byte[4];
        bytes[0]=(byte)(i >> 3*8);
        bytes[1]=(byte)(i >> 2*8);
        bytes[2]=(byte)(i >> 1*8);
       bytes[3]=(byte)(i >> 0*8);
       return bytes;
    }
    //反序列化
    pulic static int byte2int(byte[]bytes)
    {
       return (bytes[0] << 3*8) |
    				(bytes[1] << 2*8) |
    				(bytes[2] << 1*8) |
    				(bytes[3] << 0*8);}
    }

阶段二  
使用byteBuff 完成序列化部分

*  可以对多种类型进行序列化、反序列化操作
 *  byteBuff要声明大小，且不能自动拓展
 *  \*\*\*\*OutputStream、\*\*\*InputStream具有自动扩容的方法

public static void main(String[] args) throws IOException {
    		
                int id = 100;
    		    nt age = 22;			
      	        ByteBuffer buffer = ByteBuffer.allocate(8);
                buffer.putInt(id);
                buffer.putInt(age);
    	    	byte[] byteArray = buffer.array();
    		//==================通过socket传输字节序列=================================   	
               ByteBuffer buffer2 = ByteBuffer.wrap(array);
    	       System.out.println("id:"+buffer2.getInt());
    		  System.out.println("age:"+buffer2.getInt());

**阶段三**  
使用Netty ChannelBuffer

*  可以自动扩容，并且可以对多种整型数据类型进行序列化、反序列化操作
 *  不能对操作String

public static void main(String[] args) {
    
    		ChannelBuffer buffer = ChannelBuffers.dynamicBuffer();
    		buffer.writeInt(101);
    		buffer.writeDouble(80.1);
    		byte[] bytes = new byte[buffer.writerIndex()];
    		buffer.readBytes(bytes);
    		System.out.println(Arrays.toString(bytes));
    		"abc".getBytes();	
    		//================================================
    		ChannelBuffer wrappedBuffer = ChannelBuffers.wrappedBuffer(bytes);
    		System.out.println(wrappedBuffer.readInt());
    		System.out.println(wrappedBuffer.readDouble());
    		
    	}

**阶段四**  
Netty ChannelBuffer对进行集成处理

*  在阶段三的基础上支持String、List等数据类型
 *  实现对类对象的序列化
 *  继承Serializer抽象类（借助Netty自定义的序列化规则）
 *  重写read()、write()时属性顺序要一致
 *  如果属性是对象的话（如，Resource），同样也要继承Serializer抽象类

public class Player extends Serializer{
    	
    	private long playerId;
    	
    	private int age;
    	
    	private List<Integer> skills = new ArrayList<>();
    	
    	private Resource resource = new Resource();
    	
    	public Resource getResource() {
    		return resource;
    	}
    
    	public void setResource(Resource resource) {
    		this.resource = resource;
    	}
    
    	public long getPlayerId() {
    		return playerId;
    	}
    
    	public void setPlayerId(long playerId) {
    		this.playerId = playerId;
    	}
    
    	public int getAge() {
    		return age;
    	}
    
    	public void setAge(int age) {
    		this.age = age;
    	}
    
    	public List<Integer> getSkills() {
    		return skills;
    	}
    
    	public void setSkills(List<Integer> skills) {
    		this.skills = skills;
    	}
    
    	@Override
    	protected void read() {
    		this.playerId = readLong();
    		this.age = readInt();
    		this.skills = readList(Integer.class);
    		this.resource = read(Resource.class);
    	}
    
    	@Override
    	protected void write() {
    		writeLong(playerId);
    		writeInt(age);
    		writeList(skills);
    		writeObject(resource);
    	}
    }

**使用案例**

*  Player、Resource对象继承了Serializer抽象类
 *  序列化：player.getBytes()
 *  反序列：player2.readFromBytes(bytes)

public static void main(String[] args) {
        		Player player = new Player();
        		player.setPlayerId(10001);
        		player.setAge(22);
        		player.getSkills().add(101);
        		player.getResource().setGold(99999);	
        		byte[] bytes = player.getBytes();//内部调用write()进行序列化		
        		System.out.println(Arrays.toString(bytes));
        		//==============================================
        		Player player2 = new Player();
        		player2.readFromBytes(bytes);//内部调用read()进行反序列化
        		System.out.println(player2.getPlayerId() + "   "+player2.getAge() + "     "+ Arrays.toString(player2.getSkills().toArray())+"   " +player2.getResource().getGold());
        
        	}

*  阶段5

Protocol Buff 对阶段四的进一步优化

*  在客户端和服务器都配置序列化配置文件
 *  ProtocolBuff内部通过位运算，可以避免Java本身数据类型新建造成空间的浪费，从而更加高效的完成序列化

//序列化
    public static byte[] toBytes() throws IOException{
    //获取一个user的构造器
    Builder builder =PlayerModule.user.newBuidler();
    //设置数据
    builder.setId(10).setAge(18).setName("luo").addSkills(1001);
    //构造对象
    User user =builder.build();
    //序列化成字节数组
    byte[] byteArray= user.toByteArray();
    return byteArray;
    }
    
    
    //反序列化
    public static void toPlayer(byte[] bs) throws Exception{
    		
    		ObjectInputStream inputStream = new ObjectInputStream(new ByteArrayInputStream(bs));
    		User player = (User)inputStream.readObject();	
    		//打印
    		 System.out.println("Id:" + player.getPlayerId());
    		 System.out.println("age:" + player.getAge());
    		 System.out.println("name:" + player.getName());
    		 System.out.println("skills:" + (Arrays.toString(player.getSkills().toArray())));
    	}

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