ajax调用servlet

1.利用myecilpse建立一个web项目

2.导入需要的包：

　　　　commons-beanutils.jar

　　　　commons-collections-3.1.jar

　　 commons-lang-2.3.jar

commons-logging-1.1.jar

ezmorph-1.0.6.jar

json-lib-2.1.jar

json-lib.2.2.2-jdk15.jar

3.建立index.jsp页面（记得导入jquery包）

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'index.jsp' starting page</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
     <script type="text/javascript" src="js/jquery.js"></script>
    <script type="text/javascript">
    function test()
    {
        //alert(1);
        $.ajax({
                url:'<%=path%>/HelloServlet',
                dataType: "json",
                data:{
                    name:"zhangsan",
                    password:"123123"
                },
                type :'GET',
                success:function(data)
                {
                    //alert(data.length);
                    //var stu = eval("(" + data + ")");
                    //alert( $(data).get(0).name);
                    //alert( $(data).get("age"));
                }
            });
    }
    
    </script>
    </head>
  
  <body>
          <table>
              <tr>
                  <td>姓名:</td>
                  <td><input type="text" id="userName" name="userName"></td>
              </tr>
              
              <tr>
                  <td>密码:</td>
                  <td><input type="text" id="passWord" name="passWord"></td>
              </tr>
              
              <tr>
                  <td><input type="button" value="提交" onclick="test();"></td>
              </tr>
          </table>
  </body>
</html>

4.建立Servlet

public class HelloServlet extends HttpServlet
{
    public HelloServlet()
    {
        super();
    }

    public void destroy()
    {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        System.out.println("执行了-------------");
        String name = (String)request.getParameter("name");
        String password = (String)request.getParameter("password");        
        System.out.println(name + " ," + password);        
        
        student stu = new student();        
        stu.setAge(18);
        stu.setName("zhangsan");
        JSONArray arr=JSONArray.fromObject(stu);
        PrintWriter out = response.getWriter();
        out.println(arr.toString());    
        out.flush();
        out.close();
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {

    }

    public void init() throws ServletException
    {
        
    }

}

5.web.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 
    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_3_0.xsd">
    
  <servlet>
    <servlet-name>HelloServlet</servlet-name>
    <servlet-class>com.milk.servlet.HelloServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>HelloServlet</servlet-name>
    <url-pattern>/HelloServlet</url-pattern>
  </servlet-mapping>
  
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>