Hessian序列化实例

淡淡的烟草味﹌ 2021-12-11 02:59 358阅读 0赞

Hessian也是一种可以做序列化的工具，他也支持多语言，这里介绍java中做序列化的示例。Hessian序列化和jdk自带的序列化，思路基本一样，只不过Hessian序列化之后，字节数更小，性能更优。另外Hessian提供了两套api，默认是hessian，也提供了一个升级版本的hessian2的序列化api，从名字上看，hessian2应该是序列化性能更优，如果使用Hessian做序列化，推荐使用升级版本的api。

这里以jdk自带的序列化和HessianOutput，Hessian2Output序列化来做对比，看看他们的序列化效果。

在使用Hessian序列化之前，需要在maven工程中，引入Hessian依赖：

<dependency>
      <groupId>com.caucho</groupId>
      <artifactId>hessian</artifactId>
      <version>4.0.62</version>
    </dependency>

无论jdk序列化，还是hessian序列化，实体类均需要实现Serializable接口，这里以Student实体为例：

package com.xxx.serial.hessian;
    
    import java.io.Serializable;
    
    public class Student implements Serializable{
    	/**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    	private int id;
    	private String name;
    	private transient String gender;
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getGender() {
    		return gender;
    	}
    	public void setGender(String gender) {
    		this.gender = gender;
    	}
    	
    	public Student() {}
    	public Student(int id,String name,String gender){
    		this.id = id;
    		this.name = name;
    		this.gender = gender;
    	}
    	
    	@Override
    	public String toString() {
    		return "User(id="+id+",name="+name+",gender="+gender+")";
    	}
    }

我们准备测试类，编写序列化，反序列化方法：

package com.xxx.serial.hessian;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.ObjectOutputStream;
    import com.caucho.hessian.io.Hessian2Input;
    import com.caucho.hessian.io.Hessian2Output;
    import com.caucho.hessian.io.HessianInput;
    import com.caucho.hessian.io.HessianOutput;
    
    public class SerialTest {
    
    	public static <T> byte[] serialize(T t){
    		byte[] data = null;
    		try {
    			ByteArrayOutputStream os = new ByteArrayOutputStream();
    			HessianOutput output = new HessianOutput(os);
    			output.writeObject(t);
    			data = os.toByteArray();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return data;
    	}
    	
    	public static <T> byte[] serialize2(T t){
    		byte[] data = null;
    		try {
    			ByteArrayOutputStream os = new ByteArrayOutputStream();
    			Hessian2Output output = new Hessian2Output(os);
    			output.writeObject(t);
    			output.getBytesOutputStream().flush();
    			output.completeMessage();
    			output.close();
    			data = os.toByteArray();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return data;
    	}
    	
    	public static <T> byte[] jdkSerialize(T t){
    		byte[] data = null;
    		try {
    			ByteArrayOutputStream os = new ByteArrayOutputStream();
    			ObjectOutputStream output = new ObjectOutputStream(os);
    			output.writeObject(t);
    			output.flush();
    			output.close();
    			data = os.toByteArray();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return data;
    	}
    	
    	@SuppressWarnings("unchecked")
    	public static <T> T deserialize(byte[] data){
    		if(data==null){
    			return null;
    		}
    		Object result = null;
    		try {
    			ByteArrayInputStream is = new ByteArrayInputStream(data);
    			HessianInput input = new HessianInput(is);
    			result = input.readObject();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return (T)result;
    	}
    	
    	@SuppressWarnings("unchecked")
    	public static <T> T deserialize2(byte[] data){
    		if(data==null){
    			return null;
    		}
    		Object result = null;
    		try {
    			ByteArrayInputStream is = new ByteArrayInputStream(data);
    			Hessian2Input input = new Hessian2Input(is);
    			result = input.readObject();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return (T)result;
    	}
    	
    	public static void main(String[] args) {
    		Student stu = new Student(1,"hessian","boy");
    		byte[] obj = serialize(stu);
    		System.out.println("hessian serialize result length = "+obj.length);
    		byte[] obj2 = serialize2(stu);
    		System.out.println("hessian2 serialize result length = "+obj2.length);
    		byte[] other = jdkSerialize(stu);
    		System.out.println("jdk serialize result length = "+other.length);
    		Student student = deserialize2(obj2);
    		System.out.println("deserialize result entity is "+student);
    	}
    
    }

运行测试类主方法，打印信息如下：

![20190712105148477.png][]

通过测试 ，我们发现hessian序列化的结果，比jdk序列化要好很多，而且hessian2序列化比hessian更好，hessian2序列化的结果几乎是jdk序列化的1/2，如果使用Hessian做序列化，推荐使用hessian2的api。

[20190712105148477.png]: /images/20211210/3a7928a74b59454a9dec975a20af3260.png