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使用ajax接收後臺傳送過來的json資料

今天給大家帶來一個簡單的使用ajax接收後臺返回json格式的demo

廢話不多說直接上程式碼


後臺程式碼

package com.sidan.outjson;

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.sidan.jsonutil.GetJson;
/**
 * Servlet implementation class OutJson
 */
@WebServlet("/OutJson")
public class OutJson extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public OutJson() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request,response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setCharacterEncoding("UTF-8");
		PrintWriter out = response.getWriter();
		String s = GetJson.getJson();
		out.print(s);
	}

}
Pserson類

package com.sidan.jsonutil;

public class Person {
	private String name;
	private String sex;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
}


將資料包裝成json格式類(資料直接是迴圈新增的所以一樣這裡是為了簡單)

package com.sidan.jsonutil;

import java.util.ArrayList;

public class GetJson {
	
	public static String getJson(){
		
		return json().toString();
	}
	
	public static StringBuffer json(){
		StringBuffer sb = new StringBuffer();
		ArrayList<Person> arr = initArray();
		int x = 0;
		sb.append("[");
		for(Person p:arr){
			sb.append("{");
			sb.append("\"name\"");
			sb.append(":");
			sb.append("\""+p.getName()+"\"");
			sb.append(",");
			sb.append("\"age\"");
			sb.append(":");
			sb.append("\""+p.getAge()+"\"");
			sb.append(",");
			sb.append("\"sex\"");
			sb.append(":");
			sb.append("\""+p.getSex()+"\"");
			sb.append("}");
			if(x != arr.size()-1){
				sb.append(",");
			}
			x++;
		}
		sb.append("]");
		return sb;
	}
	
	public static ArrayList<Person> initArray(){
		ArrayList<Person> arr = new ArrayList<Person>();
		for(int i = 0;i < 10;i++){
			Person p = new Person();
			p.setName("sdchen");
			p.setAge(20);
			p.setSex("man");
			arr.add(p);
		}
		return arr;
	}
}
jsp頁面程式碼
<pre name="code" class="html"><%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<script src="jQuery/jquery-3.1.1.min.js"></script>
<script type="text/javascript">
	$(function(){
		$("#btn").click(function(){
			var url = "OutJson";
			$.ajax({
				url:url,
				type:"post",
				dataType:"json",
				error:function(XMLHttpRequest, textStatus, errorThrown){
					alert(XMLHttpRequest);
					alert(textStatus);
					alert(errorThrown);
				},
				success:function(data){
					$.each(data,function(idx,obj){
						var li = document.createElement("li");
	                    li.innerHTML = "<a>" + obj.name + "</a>";
	                    document.getElementById("ul1").appendChild(li);
					});
				}
			});
		});
		
	});
</script>
</head>
<body>
	<ul id="ul1"></ul>
    <input type="button" value="迴圈" id="btn"/>
</body>
</html>


 寫這個demo也費了很大勁,畢竟是新手,也從錯誤中學到了很多,比如dataType寫成datatype時ajax預設接收的資料是為text這樣導致我總是迴圈不了,還有就是json資料的格式是非常嚴謹的 
 



就因為最後多了一個逗號就導致總是出錯,並且迴圈不了,最後將錯誤打印出來才知道這個格式是錯了的