package cn.java.gson;

import com.google.gson.JsonElement;

import com.google.gson.JsonObject;

import com.google.gson.JsonParser;

public class Test {

    public static void main(String[] args) {

        dataType();

        dataObj();

        dataArray();

    }

    public static void dataType() {

        String jsonStr = "{\"code\":200,\"message\":\"message\",\"data\":[]}";

        JsonObject jsonObject = (JsonObject) new JsonParser().parse(jsonStr);

        System.out.println(jsonObject.get("code"));

        System.out.println(jsonObject.get("message").toString());

        System.out.println(jsonObject.get("message").getAsString());

        String dataStr = jsonObject.get("data").toString();

        if ( "{}".equals(dataStr) || "[]".equals(dataStr) || ("" == dataStr)) {

            System.out.println("data is empty..");

        }

    }

    public static void dataObj() {

        String jsonStr = "{\"code\":2,\"message\":2,\"data\":{}}";

        JsonObject jsonObject = (JsonObject) new JsonParser().parse(jsonStr);

        for (java.util.Map.Entry<String, JsonElement> entry : jsonObject.entrySet()) {

            System.out.print(entry.getKey() + "=" + entry.getValue() + "\t");

        }

        System.out.println();

    }

    public static void dataArray() {

        String jsonStr = "{\"code\":2,\"message\":2,\"data\":[]}";

        JsonObject jsonObject = (JsonObject) new JsonParser().parse(jsonStr);

        for (java.util.Map.Entry<String, JsonElement> entry : jsonObject.entrySet()) {

            System.out.print(entry.getKey() + "=" + entry.getValue() + "\t");

        }

        System.out.println();

    }

}

200

"message"

message

data is empty..

code=2    message=2    data={}

code=2    message=2    data=[]