AJAX基础学习4之JSON
2014-07-29 15:08
351 查看
1、解析JSON
JSON只是一种文本字符串。它被存储在responseText属性中
为了读取存储在responseText属性中的JSON数据,需要根据JavaScript的eval语句。函数eval会把一个字符串当做他的参数。然后这个字符串会被当做JavaScript代码来执行。因为JSON的字符串就是有JavaScript代码构成的。所以它本身是可执行的
具体代码:
JSP
web.xml
AccessServlet.java
ajaxutil.js
运行结果:
注:
①使用eval函数将传过来的JSON数据转换成对象,之后再根据转换成的对象属性获取值
②在自己写的JSON字符串是注意格式不要写错。在字符转值使用' ' 隔开,以免将字符串与属性混,造成浏览器无法解析
2、获取多个JSON对象
JSP
AccessServlet.java
ajaxutil.js
注:
获取多个对象时在用数组方式进行获取
3、
JSON只是一种文本字符串。它被存储在responseText属性中
为了读取存储在responseText属性中的JSON数据,需要根据JavaScript的eval语句。函数eval会把一个字符串当做他的参数。然后这个字符串会被当做JavaScript代码来执行。因为JSON的字符串就是有JavaScript代码构成的。所以它本身是可执行的
具体代码:
JSP
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <script type="text/javascript" src="./js/ajaxutil.js"></script> <title>My JSP 'index.jsp' starting page</title> </head> <body> <form action="" enctype="application/x-www-form-urlencoded"> <input type="button" value="提交" name="ok" id="ok"/> </form> </body> </html>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name></display-name> <servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>AccessServlet</servlet-name> <servlet-class>com.servlet.AccessServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AccessServlet</servlet-name> <url-pattern>/accessServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
AccessServlet.java
package com.servlet; 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; public class AccessServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // request.setCharacterEncoding("UTF-8"); // response.setContentType("html/text,charset=UTF-8"); // PrintWriter out = response.getWriter(); // // System.out.println("****************************"); // System.out.println("a:"+request.getParameter("a")); // System.out.println("b:"+request.getParameter("b")); // System.out.println("c:"+request.getParameter("c")); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("html/text,charset=UTF-8"); PrintWriter out = response.getWriter(); // System.out.println("**post***********************"); // System.out.println("a:"+request.getParameter("a")); // System.out.println("b:"+request.getParameter("b")); // System.out.println("c:"+request.getParameter("c")); System.out.println("*******1************"); String str = "{pid:10,pname:'zhutianpeng'}"; out.println(str); System.out.println("***********2*********"); } }
ajaxutil.js
/** * 创建XMLHttpRequest对象 * @returns */ function ajaxFunction(){ var httpRequest; try{ //Firefox,Opera 8.0+ ,Safari httpRequest = new XMLHttpRequest(); }catch(e){ try{ //Internet Explorer httpRequest = new ActionXObject("Msxm12.XMLHTTP"); }catch(e){ try{ httpRequest = new ActionXObject("Microsoft.XMLHTTP"); }catch(e){} } } return httpRequest; } window.onload = function(){ //<input type="button" name="ok" id="ok" value="测试服务器连接"> /** * GET方法 */ // document.getElementById("ok").onclick=function(){ // // //1.获取XMLHttpRequest对象 // var xmlRequest = ajaxFunction(); // // xmlRequest.onreadystatechange=function(){ // if(xmlRequest.readyState==4){ // if(xmlRequest.status==200||xmlRequest.statue==304){ // //接收服务器返回的数据 // var date = xmlRequest.responseText; // // } // } // } // //2.打开连接 // xmlRequest.open("get","./accessServlet?timeStamp="+new Date().getTime()+"&a=9",true); // //3.发送数据 // xmlRequest.send(null); // //4.接收数据 // // } /** * POST方法 */ document.getElementById("ok").onclick=function(){ //1.获取XMLHttpRequest对象 var xmlRequest = ajaxFunction(); xmlRequest.onreadystatechange=function(){ if(xmlRequest.readyState==4){ if(xmlRequest.status==200||xmlRequest.statue==304){ //接收服务器返回的数据 var data = xmlRequest.responseText; var dataObj = eval("("+data+")"); alert("pid:"+dataObj.pid+" pname:"+dataObj.pname); } } } //2.打开连接 // xmlRequest.open("post","./accessServlet?timeStamp="+new Date().getTime()+"&a=9",true); // xmlRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); // //3.发送数据 // xmlRequest.send("b= 00&c=9"); // //4.接收数据 xmlRequest.open("post","./accessServlet?timeStamp="+new Date().getTime(),true); xmlRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); //3.发送数据 xmlRequest.send(null); //4.接收数据 } }
运行结果:
注:
①使用eval函数将传过来的JSON数据转换成对象,之后再根据转换成的对象属性获取值
②在自己写的JSON字符串是注意格式不要写错。在字符转值使用' ' 隔开,以免将字符串与属性混,造成浏览器无法解析
2、获取多个JSON对象
JSP
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <script type="text/javascript" src="./js/ajaxutil.js"></script> <title>My JSP 'index.jsp' starting page</title> </head> <body> <form action="" enctype="application/x-www-form-urlencoded"> <input type="button" value="提交" name="ok" id="ok"/> </form> </body> </html>
AccessServlet.java
package com.servlet; 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; public class AccessServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // request.setCharacterEncoding("UTF-8"); // response.setContentType("html/text,charset=UTF-8"); // PrintWriter out = response.getWriter(); // // System.out.println("****************************"); // System.out.println("a:"+request.getParameter("a")); // System.out.println("b:"+request.getParameter("b")); // System.out.println("c:"+request.getParameter("c")); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("html/text,charset=UTF-8"); PrintWriter out = response.getWriter(); // System.out.println("**post***********************"); // System.out.println("a:"+request.getParameter("a")); // System.out.println("b:"+request.getParameter("b")); // System.out.println("c:"+request.getParameter("c")); System.out.println("*******1************"); String str = "[{pid:10,pname:'zhutianpeng'},{pid:11,pname:'zhutianpeng1'},{pid:12,pname:'zhutianpeng2'}]"; out.println(str); System.out.println("***********2*********"); } }
ajaxutil.js
/** * 创建XMLHttpRequest对象 * @returns */ function ajaxFunction(){ var httpRequest; try{ //Firefox,Opera 8.0+ ,Safari httpRequest = new XMLHttpRequest(); }catch(e){ try{ //Internet Explorer httpRequest = new ActionXObject("Msxm12.XMLHTTP"); }catch(e){ try{ httpRequest = new ActionXObject("Microsoft.XMLHTTP"); }catch(e){} } } return httpRequest; } window.onload = function(){ //<input type="button" name="ok" id="ok" value="测试服务器连接"> /** * GET方法 */ // document.getElementById("ok").onclick=function(){ // // //1.获取XMLHttpRequest对象 // var xmlRequest = ajaxFunction(); // // xmlRequest.onreadystatechange=function(){ // if(xmlRequest.readyState==4){ // if(xmlRequest.status==200||xmlRequest.statue==304){ // //接收服务器返回的数据 // var date = xmlRequest.responseText; // // } // } // } // //2.打开连接 // xmlRequest.open("get","./accessServlet?timeStamp="+new Date().getTime()+"&a=9",true); // //3.发送数据 // xmlRequest.send(null); // //4.接收数据 // // } /** * POST方法 */ document.getElementById("ok").onclick=function(){ //1.获取XMLHttpRequest对象 var xmlRequest = ajaxFunction(); xmlRequest.onreadystatechange=function(){ if(xmlRequest.readyState==4){ if(xmlRequest.status==200||xmlRequest.statue==304){ //接收服务器返回的数据 var data = xmlRequest.responseText; var dataObj = eval("("+data+")"); // alert("pid:"+dataObj.pid+" pname:"+dataObj.pname); for(var i=0;i<dataObj.length;i++){ alert("pid:"+dataObj[i].pid+" pname:"+dataObj[i].pname); } } } } //2.打开连接 // xmlRequest.open("post","./accessServlet?timeStamp="+new Date().getTime()+"&a=9",true); // xmlRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); // //3.发送数据 // xmlRequest.send("b= 00&c=9"); // //4.接收数据 xmlRequest.open("post","./accessServlet?timeStamp="+new Date().getTime(),true); xmlRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); //3.发送数据 xmlRequest.send(null); //4.接收数据 } }运行结果:
注:
获取多个对象时在用数组方式进行获取
3、
相关文章推荐
- AJAX基础学习4之JSON
- AJAX基础学习3之JSON
- 【Java EE 学习 31】【JavaScript基础增强】【Ajax基础】【Json基础】
- Ajax基础教程学习(5)_读取响应首部
- Ajax基础学习(一)——学号验证
- Ajax - 基础教程第八章例子学习四
- Ajax - 基础教程第八章例子学习五
- Ajax - JSON (JavaScript Object Notation)学习
- Ajax基础教程学习(3)_创建自动刷新页面
- 转载--Ajax学习---使用 JSON 进行数据传输
- JSON基础学习
- 【AJAX学习笔记】JSON数据编码解码技术
- 实例学习AJAX-基础1
- Ajax学习——JSON
- ArcGIS客户端开发学习笔记(三)——JSON基础
- AJAX学习之序列二:struts2 jquery json 实现AJAX 注册ID验证
- AJAX学习基础:简单介绍数据岛使用方法
- 实例学习AJAX-基础1
- 实例学习AJAX-基础1