序列化和反序列化（七）——Java对象的网络传输（二）

阳光穿透心脏的1/2处 2022-02-15 14:42 246阅读 0赞

《Java对象的网络传输（一）》中分别介绍了如何通过Socket和HTTP实现Java对象的网络传输，其实现原理如出一辙——将Java对象转换成二进制进行传输，这种方式要求项目工程必须是Java或Java Web工程，如果要将Java对象状态网络传输至C、C\#等异构项目，或传至浏览器客户端，进而浏览器客户端解析为JavaScript对象，这种将Java对象转换成二进制进行传输的方式是无法实现的，为了解决这一问题通常将Java对象转换为XML或Json格式，接下来以HTTP协议为例演示如何转换为Json进而实现网络传输：

keeper Java Web工程：

UserInfo类：

package com.jd.vo;
    
    public class UserInfo{//没有实现Serializable接口
    
    	private int age;
    	private String name;
    	
    	public int getAge() {
    		return age;
    	}
    	public void setAge(int age) {
    		this.age = age;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    }

服务器端：

package com.jd.servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import com.google.gson.Gson;
    import com.jd.vo.UserInfo;
    
    @WebServlet("/DataServlet")
    public class DataServlet extends HttpServlet {
    	
    	private static final long serialVersionUID = 1L;
      
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		PrintWriter out =  response.getWriter();
    		
    		UserInfo userInfo = new UserInfo();
    		userInfo.setAge(20);
    		userInfo.setName("Tom");
    		
    		String json = new Gson().toJson(userInfo);
    		out.write(json);
    		out.flush();
    		out.close();
    	}
    }

venus Java工程：

UserInfo类：同keeper工程UserInfo类

客户端：

package com.jd.test;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import com.google.gson.Gson;
    import com.jd.vo.UserInfo;
    
    public class Test {
    
    	public static void main(String[] args) {
    		try {
    			CloseableHttpClient httpclient = HttpClients.createDefault();
    			HttpGet httpGet = new HttpGet("http://127.0.0.1:8080/keeper/DataServlet");// 创建http GET请求
    			CloseableHttpResponse response = httpclient.execute(httpGet);// 执行请求
    			if (response.getStatusLine().getStatusCode() == 200) {// 判断返回状态是否为200
    				HttpEntity entity = response.getEntity();
    				String json = EntityUtils.toString(entity);
    				UserInfo userInfo = new Gson().fromJson(json, UserInfo.class);
    				System.out.println(userInfo);
    			}
    			response.close();
    			httpclient.close();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    }

注意：

上例中服务器端和客户端创建用于网络传输的Java对象类没有实现Serializable接口；

为了便于将Java对象转换为Json，第三方开源组织提供了很多jar包：

fastjson：

[https://mvnrepository.com/artifact/com.alibaba/fastjson][https_mvnrepository.com_artifact_com.alibaba_fastjson]

gson：

[https://mvnrepository.com/artifact/com.google.code.gson/gson][https_mvnrepository.com_artifact_com.google.code.gson_gson]

JackJson：

[https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations][https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-annotations]

[https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core][https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-core]

[https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind][https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-databind]

[https_mvnrepository.com_artifact_com.alibaba_fastjson]: https://mvnrepository.com/artifact/com.alibaba/fastjson
[https_mvnrepository.com_artifact_com.google.code.gson_gson]: https://mvnrepository.com/artifact/com.google.code.gson/gson
[https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-annotations]: https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations
[https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-core]: https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core
[https_mvnrepository.com_artifact_com.fasterxml.jackson.core_jackson-databind]: https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind