https://github.com/google/gson

package com.example.wolf;

import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

public class GSONTest {

    public static void main(String[] args) {
        try (BufferedReader br = new BufferedReader(new FileReader("JSONString.txt"))) {
            String line;
            StringBuilder sb = new StringBuilder();
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }
            JsonObject root = new JsonParser().parse(sb.toString()).getAsJsonObject();
            JsonArray peopleArray = root.getAsJsonArray("people");
            for (int i = 0; i != peopleArray.size(); ++i) {
                JsonObject elem = peopleArray.get(i).getAsJsonObject();
                String peopleName = elem.get("people_name").getAsString();
                String peopleId = elem.get("people_id").getAsString();
                String tip = elem.get("tip").getAsString();
                System.out.println("people_name: " + peopleName + "\npeople_id: " + peopleId + "\ntip: " + tip);
            }
            System.out.println();
            int peopleCount = root.get("people_count").getAsInt();
            String crowdName = root.get("crowd_name").getAsString();
            String crowdId = root.get("crowd_id").getAsString();
            String tip = root.get("tip").getAsString();
            System.out.println("people_count: " + peopleCount + "\ncrowd_name: " + crowdName + "\ncrowd_id: " + crowdId + "\ntip: " + tip + '\n');
        } catch (IOException ex) {
            Logger.getLogger("JSONTest").log(Level.SEVERE, null, ex);
        } finally {
            JsonObject jsonObject = new JsonObject();
            JsonArray faceArray = new JsonArray();
            JsonObject arrayElement = new JsonObject();
            JsonObject attributeObject = new JsonObject();
            attributeObject.addProperty("age", 19);
            attributeObject.addProperty("gender", "Female");
            attributeObject.addProperty("lefteye_opendegree", 44);
            attributeObject.addProperty("righteye_opendegree", 39);
            attributeObject.addProperty("mouth_opendegree", 32);
            JsonObject poseObject = new JsonObject();
            poseObject.addProperty("raise", -1);
            poseObject.addProperty("tilting", -7);
            poseObject.addProperty("turn", -3);
            attributeObject.add("pose", poseObject);
            arrayElement.add("attribute", attributeObject);
            arrayElement.addProperty("face_id", "dd6faefeb13a4dcebc14328891bdf6df");
            JsonObject positionObject = new JsonObject();
            JsonObject centerObject = new JsonObject();
            centerObject.addProperty("x", 152);
            centerObject.addProperty("y", 92);
            positionObject.add("center", centerObject);
            JsonObject leftEyeObject = new JsonObject();
            leftEyeObject.addProperty("x", 209);
            leftEyeObject.addProperty("y", 152);
            positionObject.add("eye_left", leftEyeObject);
            JsonObject rightEyeObject = new JsonObject();
            rightEyeObject.addProperty("x", 312);
            rightEyeObject.addProperty("y", 151);
            positionObject.add("eye_right", rightEyeObject);
            positionObject.addProperty("width", 218);
            positionObject.addProperty("height", 218);
            arrayElement.add("position", positionObject);
            arrayElement.addProperty("tag", "");
            faceArray.add(arrayElement);
            jsonObject.add("face", faceArray);
            jsonObject.addProperty("img_width", 537);
            jsonObject.addProperty("img_height", 480);
            jsonObject.addProperty("img_id", "020-334630e8948f3403");
            jsonObject.addProperty("url", "http://www.eyekey.com/images/demo/BaiBaihe/2.jpg");
            System.out.println(jsonObject);
        }
    }
}

JSONString.txt

{
	"people":
	[
		{
			"people_name": "test people",
			"people_id": "22fd9efc64c87e00224c33dd8718eec7",
			"tip": "people test tip"
		}
	],
	"people_count": 20,
	"crowd_name": "test",
	"crowd_id": "22fd9efc64c87e00224c33dd8718eec7",
	"tip": "test tip"
}
05-21 00:45