日期:2014-05-16  浏览次数:20401 次

fastjson生成和解析json数据


本文讲解2点:

1. fastjson生成和解析json数据

  (举例:4种常用类型:JavaBean,List<JavaBean>,List<String>,List<Map<String,Object>)

2.通过一个android程序测试fastjson的用法。

fastjson简介:

Fastjson是一个Java语言编写的高性能功能完善的JSON库。fastjson采用独创的算法,将parse的速度提升到极致,超过所有json库,包括曾经号称最快的jackson。并且还超越了google的二进制协议protocol buf。Fastjson完全支持http://json.org的标准,也是官方网站收录的参考实现之一。支持各种JDK类型。包括基本类型、JavaBean、Collection、Map、Enum、泛型等。支持JDK 5、JDK 6、Android、阿里云手机等环境。

一. fastjson生成json字符串(JavaBean,List<JavaBean>,List<String>,List<Map<String,Object>)

     String jsonStrng = JSON.toJSONString(object);

二. fastjson 解析json字符串为四种类型

      1. JavaBean

          Person person = JSON.parseObject(jsonString, Person.class);

      2. List<JavaBean>

          List<Person> listPerson =JSON.parseArray(jsonString, Person.class);

      3. List<String>

          List<String> listString = JSON.parseArray(jsonString, String.class);

      4. List<Map<String,Object>>

          List<Map<String, Object>> listMap = JSON.parseObject(jsonString, new TypeReference<List<Map<String,Object>>>(){});  (注意:此处可看出fastjson反射机制比gson更准确, id = 1001 通过fastjson反射仍是 id = 1001 , 而通过gson反射结果 为 id =1001.0 ,参考前篇程序运行结果图GSON方式生成和解析json数据)

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程序运行结果:

1. 点击“解析Person数据”按钮

2. 点击“解析Persons数据按钮”

3.点击“解析listString数据”按钮

4.点击“解析listMap数据”按钮

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客户端eclipse android工程目录(左边)服务器端myeclipse web工程(右边)

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服务器端 fastjson_Project

1.FastJsonAction.java

package com.fastjson.action;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.fastjson.service.FastJsonService;
import com.fastjson.tools.*;

public class FastJsonAction extends HttpServlet {



	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {