jquery跨域Ajax请求

关键：ajax的dataType为jsonp，并且在请求的url中加上"?jsoncallback=?"

前台代码：

<script type="text/javascript" src="jquery-1.7.2.min.js"></script> 
<script type="text/javascript">
    function RegisterRequest2() {
        /* getJSON method is ok also... 
        $.getJSON("http://192.168.1.154:7087/ClusterServer/Rigister?jsoncallback=?", { pwd: '123', username: 'tl' }, function(json) { alert(json.name); });　
        */
         
        $.ajax({
            url: "http://192.168.1.154:7087/ClusterServer/Rigister?jsoncallback=?",
            type: "GET",
            data: { pwd: '123', username: 'tl' },
            dataType: "jsonp",
            success: function(data) {
                alert(data.name);
            },
            error: function(a, b, c) {
                alert("error==" + b);
            }

        }); 
    }  
</script>
<input type="button" onclick="RegisterRequest2();"  value="StartRequest" />

 

后台Servlet代码：

import java.io.IOException;

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

public class Rigister extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException { 
		String pwd = req.getParameter("pwd");
		String username =req.getParameter("username");
		System.out.println("get=="+username+"  ==="+pwd);
		 
		String callback = req.getParameter("jsoncallback"); 
		resp.getWriter().write(callback + "({name:'tzy',phone:'123'})"); //参数为json格式
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException { 
		String pwd = req.getParameter("pwd");
		String username =req.getParameter("username");
		System.out.println("post=="+username+"  ==="+pwd);
		 
		String callback = req.getParameter("jsoncallback"); 
		resp.getWriter().write(callback + "({name:'tzy',phone:'123'})"); 
	}

}

 

后台返回前台的时候取出jsoncallback回调函数名，将json格式的数据作为函数的参数，整个以字符串的形式返回给前台。。