Ajax back-and-forth interaction returns both normal and JSON formats __ajax

using Ali Fastjson below is Pom.xml

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactid>fastjson</ artifactid>
            <version>1.2.9</version>
        </dependency>

Ajax return String

    JS foreground ajax note introduces jquery files such as jquery.min.js function Testajax () {//text value var uname = $ ("#username"). VA
        L ();
        var pwd = $ ("#password"). Val (); Alert (PWD) $.ajax ({type: ' post ',//Submit as URL: "...) /returnstring.do ",//path//Parameter data: {username:uname, password : pwd}, Cache:false,//return to normal character streams do not write DataType: "JSON" success:functio
            N (data) {alert (data);
    }
        }); //html code I bind is focus lost event so I added a test box <form action= "#" id= "MyForm" > Name: <input type= "text" id= "Usernam" E "name=" username "/><br/> Password: <input type=" text "name=" password "id=" password "onblur=" Testajax "() "/> <br/> Test box: <input type=" text "/>" <br/> ${pagecontext.request.contextpath} </form >//Background code is just functional testing without writing the actual content @RequestMapping ("/returnsTring ")//This is the Spring framework annotation public void returnstring (String username,string password,httpservletresponse response) {
        System.out.println (Username+password);
        try {//write out Object Stream Response.getwriter (). println ("test string");
        catch (IOException e) {e.printstacktrace (); }
    }

Ajax return to JSON format

    Foreground Ajax
Function returnjsonlist () {
        $.ajax ({
            type: ' Post ',
            URL: ' ... /returnjsonlist.do ',
            dataType: "JSON",
            success:function (data) {
                alert (data);
                The number of I loops  value Object Id,name is a property
                $.each (data, function (I, value) {                          
                            $ ("#remark"). Append (
                             "<tr ><td> "+ value.id +" </td><td> "
                                    + value.name +" </td><td> "+ value.t
                                    +" </ Td><td> "+ value.x + </td></tr>");} 
                );}
    

//html code Test button Click Time then return to the collection stitching to the table <input type= "button" name= "Test return to JSON format list collection" onclick= "Returnjsonlist ()"/> <table class= "Table table-striped" id= "remark" > <tr> <TD&G T; School number </td> <td> name </td> <td> date </td> <td> age </td>
        ; </tr> </table> 

Background code @RequestMapping ("/returnjsonlist") public void Testprco (HttpServletResponse response) {System.out.print
        ln ("OK returnjsonlist");
            try {list<demo> List = new arraylist<> ();
            Demo D1 = new Demo (1, "Test", New Date ());
            Demo D2 = new Demo (2, "Test", New Date ());
            Demo D3 = new Demo (3, "Test", New Date ());
            Date conversions are added @jsonfield (format= "Yyyy-mm-dd") List.add (D1) on entity object attributes;
            List.add (D2);
            List.add (D3);
            /*map<integer, string> Map = new hashmap<> ();
            Map.put (1, "test01");
            Map.put (2, "test02");
            Map.put (3, "test03");//simple rough, for map This sentence also applies String json = json.tojsonstring (list);
            SYSTEM.OUT.PRINTLN (JSON);
        Get flow to JSP pass Data Response.getwriter (). println (JSON);
        catch (IOException e) {e.printstacktrace ();
 }
    }

attached
JSON format Conversion

public static void Main (string[] args) {
             list<object> List = new arraylist<> ();
             List.add ("test");
             List.add ("Test 2");
             List.add ("Test 3");
             JSON format Conversion  map strings are adapted to
             string str = json.tojsonstring (list);
             System.out.println (str);
    

Results

[Test, Test 2, Test 3]