关于json前后台传值

原创于我的网易博客,地址http://yannanying.blog.163.com/blog/static/2211131172014410115730322/

后台.java

	HttpServletResponse response = ServletActionContext.getResponse();

	public void checkUserIdCard() throws Exception {
		System.out.println("idCard="+user.getIdCard());
		JSONObject jobj = new JSONObject();
		boolean flag = this.userService.findByUserIdCard(user.getIdCard());
		System.out.println(flag);
		jobj.put("success", flag);
		System.out.println("返回前台的flag==="+flag+"------true表示可以使用，false表示数据库已存在此用户名");
		ResponseUtil.write(response, jobj);

工具类ResponseUtil.java

/**
 * 
 */
package com.rcpy.util;

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

import javax.servlet.http.HttpServletResponse;

/**
 * @author phn
 *
 */
public class ResponseUtil {
	public static void write(HttpServletResponse response,Object obj) throws IOException{
		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		out.print(obj.toString());
		out.flush();
		out.close();
	}

}

struts.xml

	<package name="userJson" namespace="/" extends="json-default,struts-default">
		<action name="User_checkUserIdCard" class="userAction" method="checkUserIdCard">
			<result name="success" type="json"></result>
		</action>
	</package>

前台.js

function checkname()	
{
	var IdCard = document.getElementById("uIdCard").value;	
	var IdCardValid = document.getElementById("uIdCardValid");
	if(IdCard.length<6 || IdCard.length>15)	
	{	
		IdCardValid.innerHTML ="用户名长度须在6-15之间!";
		IdCardValid.style.color="red";
	    return false;
	}
	$.post("User_checkUserIdCard.action", {"user.idCard": IdCard },function(data){
		var d = $.parseJSON(data);
		console.log(d);
		if(d.success==false){
			IdCardValid.innerHTML ='用户名已存在!';
			IdCardValid.style.color='red';
			 return true;
		}
	});
	IdCardValid.innerHTML ='用户名可以使用！';
	IdCardValid.style.color='green';
	return true;
}

使用json必须的6个jar包

1.commons-beanutils-1.7.0.jar

2.commons-collections-3.2.1.jar

3.commons-lang-2.3.jar

4.commons-logging-1.0.4.jar

5.ezmorph-1.0.3.jar

6.json-lib-2.1.jar