Java, JS (jQuery) and Ajax. Get a specific value of JSON.

Get the specific value of the data returned by JSON type from Java with jQuery (client side).

A memorandum of processing that handles JSON Uses Struts 1.3.10.

Ajax with JS. Call Java.

main.js

$.ajax({
    url     : "./SearchBook.do",
    type    : "POST",
    async   : true,
    data    : "Data to throw to Java here",
    dataType: "json",
    success : function(result) {
        //Processing on success
    }
});

Put the result of various processing with the data received from JS into JSON type on Java side. String type and int type are prepared as data.

main.java

String title = "spark"
int totalPage = 152;

JSONObject result = new JSONObject();
result.put("title", title);
result.put("number of pages", totalPage);

The JSON type below is returned. {"Title ":" Sparks "," Number of pages ":" 152 "}

$.ajax({
    --abridgement--
    success	: function(result) {
        //Processing on success
    }
});

All you have to do is retrieve the target value with the key.

main.js

success	: function(result) {
    //Processing on success
    $("#foo").text(result["title"]);
    $("#bar").text(result["number of pages"]);
}

For the time being, this is done. If there is a better way, please teach me.

There is also a different way of writing ...

Change the key to alphabetic characters in Java.

main.java

String title = "spark"
int totalPage = 152;

JSONObject result = new JSONObject();
result.put("bookTitle", title);
result.put("totalPage", totalPage);

On the JS side, connect with. (Dot) and specify the key to get the value.

main.js

$.ajax({
    url     : "./SearchBook.do",
    type    : "POST",
    async   : true,
    data    : "Data to throw to Java here",
    dataType: "json",
    success	: function(result) {
        //Processing on success
        $("#foo").text(result.bookTitle);
        $("#bar").text(result.pager.totalPage);
}

Whether to parse or not

• If you specify dataType:" json " and JSON type in dataType of ajax, you did not need to parse. Conversely, parse will result in an error.

in short...

main.js

$.ajax({
    url     : "./SearchBook.do",
    type    : "POST",
    async   : true,
    data    : "Data to throw to Java here",
    dataType: "json",
    success	: function(result) {
        //Processing on success
        $("#foo").text(result["title"]);
        $("#bar").text(result["number of pages"]);
    }
});

Or

main.js

$.ajax({
    url     : "./SearchBook.do",
    type    : "POST",
    async   : true,
    data    : "Data to throw to Java here",
    success	: function(result) {
        //Processing on success
        var data = JSON.parse(result);
        $("#foo").text(result["title"]);
        $("#bar").text(result["number of pages"]);
    }
});

To be.