ajax+json+java

標籤：

1.首先下載json所以依賴的包， Json-lib 最新版 json-lib-2.3-jdk15.jar，其官方網站是：http://json-lib.sourceforge.net/可以直接download，細心的你會發現其網站頁面裡面有提示它還需要其他包： 
Json-lib requires (at least) the following dependencies in your classpath: 
•jakarta commons-lang 2.4 
•jakarta commons-beanutils 1.7.0 
•jakarta commons-collections 3.2 
•jakarta commons-logging 1.1.1 
•ezmorph 1.0.6 
分別是： 
http://commons.apache.org/lang/ 
http://commons.apache.org/beanutils/ 
http://commons.apache.org/collections/ 
http://commons.apache.org/logging/ 
http://ezmorph.sourceforge.net/ 

 

2.首先先見一個小web項目 
User類： 

package com.json;public class User {    String username;    String password;    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    }

 

servlet :

package com.json;import java.io.IOException;import java.io.PrintWriter;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import net.sf.json.JSONArray;public class TestJson extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {           doPost(request,response);    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        response.setContentType("text/html");   　　　　 String str= =request.getParameter("name");//得到ajax傳遞過來的paramater        PrintWriter out = response.getWriter();        List list = new ArrayList();//傳遞List        Map m=new HashMap();//傳遞Map            User u1=new User();        u1.setUsername("zah");        u1.setPassword("123");        User u2=new User();        u2.setUsername("ztf");        u2.setPassword("456");            list.add(u1); //添加User對象              list.add(u2);     //添加User對象                m.put("u1", u1);        m.put("u2", u2);          JSONArray jsonArray2 = JSONArray.fromObject( list );       //把java數組轉化成轉化成json對象        JSONObject jo=JSONObject.fromObject(m);       //轉化Map對象       out.print(jsonArray2);//返給ajax請求       out.print(jo);//返給ajax請求    }}

 

ajax實現:

<script type="text/javascript" src="js/jquery.js"></script><script type="text/javascript">     function test(){         $.ajax({                 type:"POST", //請求方式                url:"testjson", //請求路徑                cache: false,                   data:"name=zah",  //傳參                dataType: ‘json‘,   //傳回值類型                success:function(json){                            alert(json[0].username+" " json[0].password);    //彈出返回過來的List對象                   }                });      }</script>
<body>   <input type="button" name="b" value="測試" onclick=test()></body>

 

輸出：zah 123 

訪問Map的話直接把返回函數改成如下即可： 

success:function(json){     alert(json.u1.username)}

 

ajax+json+java