JSon Client Code

JSon Client Code

package com.javanotes2all.client;

import java.util.Set;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.json.client.JSONArray;
import com.google.gwt.json.client.JSONBoolean;
import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.json.client.JSONString;
import com.google.gwt.json.client.JSONValue;
import com.google.gwt.user.client.HTTPRequest;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;

/**
 * Entry point classes define onModuleLoad().
 */
public class Test implements EntryPoint {

	public void onModuleLoad() {		
		String firstJSON="{'wz':'123','java':111,'other':['zhangsan','lisi'],'obj':{'name':'jam','age':18,'married':true,'child':null,'likes':['cat','dog']}}";
		JSONValue value=JSONParser.parse(firstJSON);
		System.out.println(value.toString());
		JSONObject o1= value.isObject();
		
		JSONValue v1=o1.get("wz");
		System.out.println("v1  "+v1.isString());
		
		JSONValue v2=o1.get("java");
		System.out.println("v2  "+v2.isNumber());
		
		JSONValue v3=o1.get("other");
		System.out.println("v3  "+v3.isArray());

		JSONObject object=new JSONObject();
		object.put("a", JSONBoolean.getInstance(true));
		object.put("b", new JSONString("yes"));
		object.put("c", new JSONNumber(1.23));
		object.put("d",JSONNull.getInstance());
		System.out.println("v6  "+object.toString());
 
		JSONArray v33=v3.isArray();
		int arraylength=v33.size();
		v33.set(arraylength, new JSONString("wangwu"));
		System.out.println("v3  "+v3.isArray());
		
		JSONObject v4=o1.get("obj").isObject();
		System.out.println("v4  "+v4.toString());
		System.out.println("v44 "+v4.get("name").isString());
		
		String jsJSON=jsmethod();
		JSONObject jsobj=JSONParser.parse(jsJSON).isObject();
		System.out.println("v5  "+jsobj);
		System.out.println("v55 "+jsobj.get("name").isString());
		
		RootPanel.get().add(new Label("success!!!"));
	}
	
	public native String jsmethod()/*-{
		var code="{'name':'Tom','age':18.0,'married':true}";
		
		return code;
	}-*/;
	
}

Send JSON-Object as POST in RequestBuilder

Send JSON-Object as POST in RequestBuilder

At client-side:

JSONArray devicedata=new JSONArray();

devicedata.set(0,"zero");

devicedata.set(1, "one");

devicedata.set(2, two);

try
{
 String url=localhost:8080/requestsend/servlet;

 RequestBuilder builder=new RequestBuilder(RequestBuilder.POST, url);

//adding the post data
 builder.setRequestData(devicedata.toString());

 builder.setCallback(new RequestCallback() 

{
 @Override
 public void onResponseReceived(Request request, Response response) 

{
  popup.setVisible(false);
  JSONValue value=JSONParser.parse(response.getText());
  JSONObject jobj=value.isObject();
  if(jobj.get("status").isString().stringValue().equalsIgnoreCase("success"))
    {

    }
  @Override
  public void onError(Request request, Throwable exception) 

  {
     Window.alert("Error occurred" + exception.getMessage());
  }
 });
builder.send();

}catch(Exception e)
{
}

At Server Side:

String s=req.getReader().readLine();
JSONArray jarray=new JSONArray(s);

convert ArrayList to JSONArray

Convert ArrayList to JSONArray

ArrayList<String> list = new ArrayList<String>();
    list.add("abc");
    list.add("xyz");
    JSONArray jsArray = new JSONArray(list);

see api click here

How to add string into JsonArray

 JSONArray list = new JSONArray();
 list.put("abc");
 list.put("xyz");