{
   "pageInfo": {
         "pageName": "abc",
         "pagePic": "http://example.com/content.jpg"
    }
    "posts": [
         {
              "post_id": "123456789012_123456789012",
              "actor_id": "1234567890",
              "picOfPersonWhoPosted": "http://example.com/photo.jpg",
              "nameOfPersonWhoPosted": "Jane Doe",
              "message": "Sounds cool. Can't wait to see it!",
              "likesCount": "2",
              "comments": [],
              "timeOfPost": "1234567890"
         }
    ]
}

import org.json.*;


JSONObject obj = new JSONObject(" .... ");
String pageName = obj.getJSONObject("pageInfo").getString("pageName");

JSONArray arr = obj.getJSONArray("posts");
for (int i = 0; i < arr.length(); i++)
{
    String post_id = arr.getJSONObject(i).getString("post_id");
    ......
}

private class Person {
    public String name;

    public Person(String name) {
        this.name = name;
    }
}

Gson g = new Gson();

Person person = g.fromJson("{"name": "John"}", Person.class);
System.out.println(person.name); //John

System.out.println(g.toJson(person)); // {"name":"John"}

JsonObject jsonObject = new JsonParser().parse("{"name": "John"}").getAsJsonObject();

System.out.println(jsonObject.get("name").getAsString()); //John

JSONObject obj = new JSONObject("{"name": "John"}");

System.out.println(obj.getString("name")); //John

ObjectMapper mapper = new ObjectMapper();
Person user = mapper.readValue("{"name": "John"}", Person.class);

System.out.println(user.name); //John

//from object to JSON
Gson gson = new Gson();
gson.toJson(yourObject);

// from JSON to object
yourObject o = gson.fromJson(JSONString,yourObject.class);

Response response = request.get(); // REST call
    JsonReader jsonReader = Json.createReader(new StringReader(response.readEntity(String.class)));
    JsonArray jsonArray = jsonReader.readArray();
    ListIterator l = jsonArray.listIterator();
    while ( l.hasNext() ) {
          JsonObject j = (JsonObject)l.next();
          JsonObject ciAttr = j.getJsonObject("ciAttributes");

JsonParserFactory factory=JsonParserFactory.getInstance();
JSONParser parser=factory.newJsonParser();
Map jsonMap=parser.parseJson(jsonString);

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>${version}</version>
</dependency>

String pageName = JsonPath.read(yourJsonString, "$.pageInfo.pageName");
String pagePic = JsonPath.read(yourJsonString, "$.pageInfo.pagePic");
String post_id = JsonPath.read(yourJsonString, "$.pagePosts[0].post_id");

com.fasterxml.jackson.databind.ObjectMapper

package com.levo.jsonex.model;

public class Page {

    private PageInfo pageInfo;
    private Post[] posts;

    public PageInfo getPageInfo() {
        return pageInfo;
    }

    public void setPageInfo(PageInfo pageInfo) {
        this.pageInfo = pageInfo;
    }

    public Post[] getPosts() {
        return posts;
    }

    public void setPosts(Post[] posts) {
        this.posts = posts;
    }

}

package com.levo.jsonex.model;

public class PageInfo {

    private String pageName;
    private String pagePic;

    public String getPageName() {
        return pageName;
    }

    public void setPageName(String pageName) {
        this.pageName = pageName;
    }

    public String getPagePic() {
        return pagePic;
    }

    public void setPagePic(String pagePic) {
        this.pagePic = pagePic;
    }

}

package com.levo.jsonex.model;

public class Post {

    private String post_id;
    private String actor_id;
    private String picOfPersonWhoPosted;
    private String nameOfPersonWhoPosted;
    private String message;
    private int likesCount;
    private String[] comments;
    private int timeOfPost;

    public String getPost_id() {
        return post_id;
    }

    public void setPost_id(String post_id) {
        this.post_id = post_id;
    }

    public String getActor_id() {
        return actor_id;
    }

    public void setActor_id(String actor_id) {
        this.actor_id = actor_id;
    }

    public String getPicOfPersonWhoPosted() {
        return picOfPersonWhoPosted;
    }

    public void setPicOfPersonWhoPosted(String picOfPersonWhoPosted) {
        this.picOfPersonWhoPosted = picOfPersonWhoPosted;
    }

    public String getNameOfPersonWhoPosted() {
        return nameOfPersonWhoPosted;
    }

    public void setNameOfPersonWhoPosted(String nameOfPersonWhoPosted) {
        this.nameOfPersonWhoPosted = nameOfPersonWhoPosted;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public int getLikesCount() {
        return likesCount;
    }

    public void setLikesCount(int likesCount) {
        this.likesCount = likesCount;
    }

    public String[] getComments() {
        return comments;
    }

    public void setComments(String[] comments) {
        this.comments = comments;
    }

    public int getTimeOfPost() {
        return timeOfPost;
    }

    public void setTimeOfPost(int timeOfPost) {
        this.timeOfPost = timeOfPost;
    }

}

{
   "pageInfo": {
         "pageName": "abc",
         "pagePic": "http://example.com/content.jpg"
    },
    "posts": [
         {
              "post_id": "123456789012_123456789012",
              "actor_id": "1234567890",
              "picOfPersonWhoPosted": "http://example.com/photo.jpg",
              "nameOfPersonWhoPosted": "Jane Doe",
              "message": "Sounds cool. Can't wait to see it!",
              "likesCount": "2",
              "comments": [],
              "timeOfPost": "1234567890"
         }
    ]
}

package com.levo.jsonex;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.levo.jsonex.model.Page;
import com.levo.jsonex.model.PageInfo;
import com.levo.jsonex.model.Post;

public class JSONDemo {

    public static void main(String[] args) {
        ObjectMapper objectMapper = new ObjectMapper();

        try {
            Page page = objectMapper.readValue(new File("sampleJSONFile.json"), Page.class);

            printParsedObject(page);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private static void printParsedObject(Page page) {
        printPageInfo(page.getPageInfo());
        System.out.println();
        printPosts(page.getPosts());
    }

    private static void printPageInfo(PageInfo pageInfo) {
        System.out.println("Page Info;");
        System.out.println("**********");
        System.out.println("tPage Name : " + pageInfo.getPageName());
        System.out.println("tPage Pic  : " + pageInfo.getPagePic());
    }

    private static void printPosts(Post[] posts) {
        System.out.println("Page Posts;");
        System.out.println("**********");
        for(Post post : posts) {
            printPost(post);
        }
    }

    private static void printPost(Post post) {
        System.out.println("tPost Id                   : " + post.getPost_id());
        System.out.println("tActor Id                  : " + post.getActor_id());
        System.out.println("tPic Of Person Who Posted  : " + post.getPicOfPersonWhoPosted());
        System.out.println("tName Of Person Who Posted : " + post.getNameOfPersonWhoPosted());
        System.out.println("tMessage                   : " + post.getMessage());
        System.out.println("tLikes Count               : " + post.getLikesCount());
        System.out.println("tComments                  : " + Arrays.toString(post.getComments()));
        System.out.println("tTime Of Post              : " + post.getTimeOfPost());
    }

}

Page Info;
****(*****
    Page Name : abc
    Page Pic  : http://example.com/content.jpg
Page Posts;
**********
    Post Id                   : 123456789012_123456789012
    Actor Id                  : 1234567890
    Pic Of Person Who Posted  : http://example.com/photo.jpg
    Name Of Person Who Posted : Jane Doe
    Message                   : Sounds cool. Can't wait to see it!
    Likes Count               : 2
    Comments                  : []
    Time Of Post              : 1234567890

{
  "order": 4711,
  "items": [
    {
      "name": "NE555 Timer IC",
      "cat-id": "645723",
      "quantity": 10,
    },
    {
      "name": "LM358N OpAmp IC",
      "cat-id": "764525",
      "quantity": 2
    }
  ]
}

JsonObject object = Json.parse(input).asObject();
int orders = object.get("order").asInt();
JsonArray items = object.get("items").asArray();

JsonObject user = Json.object().add("name", "Sakib").add("age", 23);

<dependency>
  <groupId>com.eclipsesource.minimal-json</groupId>
  <artifactId>minimal-json</artifactId>
  <version>0.9.4</version>
</dependency>

{
"pageInfo": {
     "pageName": "abc",
     "pagePic": "http://example.com/content.jpg"
}
"posts": [
     {
          "post_id": "123456789012_123456789012",
          "actor_id": "1234567890",
          "picOfPersonWhoPosted": "http://example.com/photo.jpg",
          "nameOfPersonWhoPosted": "Jane Doe",
          "message": "Sounds cool. Can't wait to see it!",
          "likesCount": "2",
          "comments": [],
          "timeOfPost": "1234567890"
     }
]

class MyModel {

    private PageInfo pageInfo;
    private ArrayList<Post> posts = new ArrayList<>();
}

class PageInfo {

    private String pageName;
    private String pagePic;
}

class Post {

    private String post_id;

    @SerializedName("actor_id") // <- example SerializedName
    private String actorId;

    private String picOfPersonWhoPosted;
    private String nameOfPersonWhoPosted;
    private String message;
    private String likesCount;
    private ArrayList<String> comments;
    private String timeOfPost;
}

MyModel model = gson.fromJson(jsonString, MyModel.class);

JSONArray rootOfPage =  new JSONArray(JSONString);

javax.json.JsonReader jr =
    javax.json.Json.createReader(new StringReader(jsonText));
javax.json.JsonObject jo = jr.readObject();

//Read the page info.
javax.json.JsonObject pageInfo = jo.getJsonObject("pageInfo");
System.out.println(pageInfo.getString("pageName"));

//Read the posts.
javax.json.JsonArray posts = jo.getJsonArray("posts");
//Read the first post.
javax.json.JsonObject post = posts.getJsonObject(0);
//Read the post_id field.
String postId = post.getString("post_id");

Message message= new ObjectMapper().readValue(jsonString, Message.class);

{
   "pageInfo": {
         "pageName": "abc",
         "pagePic": "http://example.com/content.jpg"
    }
    "posts": [
         {
              "post_id": "123456789012_123456789012",
              "actor_id": 1234567890,
              "picOfPersonWhoPosted": "http://example.com/photo.jpg",
              "nameOfPersonWhoPosted": "Jane Doe",
              "message": "Sounds cool. Can't wait to see it!",
              "likesCount": 2,
              "comments": [],
              "timeOfPost": 1234567890
         }
    ]
}

@Generated("org.jsonschema2pojo")
public class Container {
    @SerializedName("pageInfo")
    @Expose
    public PageInfo pageInfo;
    @SerializedName("posts")
    @Expose
    public List<Post> posts = new ArrayList<Post>();
}

@Generated("org.jsonschema2pojo")
public class PageInfo {
    @SerializedName("pageName")
    @Expose
    public String pageName;
    @SerializedName("pagePic")
    @Expose
    public String pagePic;
}

@Generated("org.jsonschema2pojo")
public class Post {
    @SerializedName("post_id")
    @Expose
    public String postId;
    @SerializedName("actor_id")
    @Expose
    public long actorId;
    @SerializedName("picOfPersonWhoPosted")
    @Expose
    public String picOfPersonWhoPosted;
    @SerializedName("nameOfPersonWhoPosted")
    @Expose
    public String nameOfPersonWhoPosted;
    @SerializedName("message")
    @Expose
    public String message;
    @SerializedName("likesCount")
    @Expose
    public long likesCount;
    @SerializedName("comments")
    @Expose
    public List<Object> comments = new ArrayList<Object>();
    @SerializedName("timeOfPost")
    @Expose
    public long timeOfPost;
}

public class MyObj {

    private PageInfo pageInfo;
    private List<Post> posts;

    static final class PageInfo {
        private String pageName;
        private String pagePic;
    }

    static final class Post {
        private String post_id;
        @JsonProperty("actor_id");
        private String actorId;
        @JsonProperty("picOfPersonWhoPosted")
        private String pictureOfPoster;
        @JsonProperty("nameOfPersonWhoPosted")
        private String nameOfPoster;
        private String likesCount;
        private List<String> comments;
        private String timeOfPost;
    }

    private static final ObjectMapper JACKSON = new ObjectMapper();
    public static void main(String[] args) throws IOException {
        MyObj o = JACKSON.readValue(args[0], MyObj.class); // assumes args[0] contains your json payload provided in your question.
    }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import com.google.gson.Gson;

public class GsonExample {
    public static void main(String[] args) {

    Gson gson = new Gson();

    try {

        BufferedReader br = new BufferedReader(
            new FileReader("c:\file.json"));

        //convert the json string back to object
        DataObject obj = gson.fromJson(br, DataObject.class);

        System.out.println(obj);

    } catch (IOException e) {
        e.printStackTrace();
    }

    }
}

JSONParser jsonParser = new JSONParser();
JSONObject obj = (JSONObject) jsonParser.parse(contentString);
String product = (String) jsonObject.get("productId");

{
   "pageInfo": {
         "pageName": "abc",
         "pagePic": "http://example.com/content.jpg"
    },
    "posts": [
         {
              "post_id": "123456789012_123456789012",
              "actor_id": "1234567890",
              "picOfPersonWhoPosted": "http://example.com/photo.jpg",
              "nameOfPersonWhoPosted": "Jane Doe",
              "message": "Sounds cool. Can't wait to see it!",
              "likesCount": "2",
              "comments": [],
              "timeOfPost": "1234567890"
         }
    ]
}

Java code :

JSONObject obj = new JSONObject(responsejsonobj);
String pageName = obj.getJSONObject("pageInfo").getString("pageName");

JSONArray arr = obj.getJSONArray("posts");
for (int i = 0; i < arr.length(); i++)
{
    String post_id = arr.getJSONObject(i).getString("post_id");
    ......etc
}

private static final String EXTRACTOR_SCRIPT =
    "var fun = function(raw) { " +
    "var json = JSON.parse(raw); " +
    "return [json.pageInfo.pageName, json.pageInfo.pagePic, json.posts[0].post_id];};";

public void run() throws ScriptException, NoSuchMethodException {
    ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
    engine.eval(EXTRACTOR_SCRIPT);
    Invocable invocable = (Invocable) engine;
    JSObject result = (JSObject) invocable.invokeFunction("fun", JSON);
    result.values().forEach(e -> System.out.println(e));
}

var fun = function(raw) {JSON.parse(raw).entries};

(JSObject) invocable.invokeFunction("fun", json);

new JSONObject(JSON).getJSONArray("entries");

mapper.readValue(JSON, Entries.class).getEntries();

Gson gson = new Gson();
JsonObject jsonObject = gson.fromJson(jsonAsString, JsonObject.class);

String pageName = jsonObject.getAsJsonObject("pageInfo").get("pageName").getAsString();
String pagePic = jsonObject.getAsJsonObject("pageInfo").get("pagePic").getAsString();
String postId = jsonObject.getAsJsonArray("posts").get(0).getAsJsonObject().get("post_id").getAsString();

JsonArray posts = jsonObject.getAsJsonArray("posts");
for (JsonElement post : posts) {
  String postId = post.getAsJsonObject().get("post_id").getAsString();
  //do something
}

JSONObject jsonObj = new JSONObject(<jsonStr>);

String id = jsonObj.getString("pageInfo");

Employee employee = null;
ObjectMapper mapper = new ObjectMapper();
try{
employee =  mapper.readValue(newFile("/home/sumit/employee.json"),Employee.class);
} catch (JsonGenerationException e){
e.printStackTrace();
}

{
  "data":
     {
        "translations":
          [
            {
              "translatedText": "Arbeit"
             }
          ]
     }
}

String json  = callToTranslateApi("work", "de");
JsonObject jsonObject = new JsonParser().parse(json).getAsJsonObject();
return jsonObject.get("data").getAsJsonObject()
        .get("translations").getAsJsonArray()
        .get(0).getAsJsonObject()
        .get("translatedText").getAsString();

class ApiResponse {
    Data data;
    class Data {
        Translation[] translations;
        class Translation {
            String translatedText;
        }
     }
 }

Gson g = new Gson();
 String json =callToTranslateApi("work", "de");
 ApiResponse response = g.fromJson(json, ApiResponse.class);
 return response.data.translations[0].translatedText;

<dependency>
            <groupId>com.jayway.jsonpath</groupId>
            <artifactId>json-path</artifactId>
            <version>2.2.0</version>
</dependency>

BufferedReader br = new BufferedReader(new FileReader("D:\sampleJson.txt"));

        StringBuilder sb = new StringBuilder();
        String line = br.readLine();

        while (line != null) {
            sb.append(line);
            sb.append(System.lineSeparator());
            line = br.readLine();
        }
        br.close();
        String jsonInput = sb.toString();

Object document = Configuration.defaultConfiguration().jsonProvider().parse(jsonInput);

String pageName = JsonPath.read(document, "$.pageInfo.pageName");
String pagePic = JsonPath.read(document, "$.pageInfo.pagePic");
String post_id = JsonPath.read(document, "$.posts[0].post_id");

System.out.println("$.pageInfo.pageName "+pageName);
System.out.println("$.pageInfo.pagePic "+pagePic);
System.out.println("$.posts[0].post_id "+post_id);

$.pageInfo.pageName = abc
$.pageInfo.pagePic = http://example.com/content.jpg
$.posts[0].post_id  = 123456789012_123456789012

{
   "pageInfo": {
         "pageName": "abc",
         "pagePic": "http://example.com/content.jpg"
    }
}

class PageInfo {

    private String pageName;
    private String pagePic;

    //getters and setters
}

PageInfo pageInfo = JsonPath.parse(jsonString).read("$.pageInfo", PageInfo.class);

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.2.0</version>
</dependency>

ObjectMapper mapper = new ObjectMapper();
JsonNode yourObj = mapper.readTree("{"k":"v"}");

JSONObject jObj = new JSONObject(contents.trim());
Iterator<?> keys = jObj.keys();

while( keys.hasNext() ) {
  String key = (String)keys.next();
  if ( jObj.get(key) instanceof JSONObject ) {
    System.out.println(jObj.getString(String key));
  }
}

{"OK":[{"tavolo":"1","pizza":"magherita","quantita":"12","note":"nothing"},{"tavolo":"1","pizza":"4formaggi","quantita":"1","note":"nothing"}],"success":1}

$result = mysql_query(your query);
if (mysql_num_rows($result) > 0) {

        $response["OK"] = array();

        while ($row = mysql_fetch_array($result)) {
            // temp user array
            $product = array();
            $product["tavolo"] = $row["tavolo"];
            $product["pizza"] = $row["pizza"];
            $product["quantita"] = $row["quantita"];
            $product["note"] = $row["note"];
            // push single product into final response array
            array_push($response["OK"], $product);
        }
        // success
        $response["success"] = 1;
        // echoing JSON response
        echo json_encode($response);
    }

//your activity..

    final String url_all_products = "yoururl.something";
    // JSON Node names
   final String TAG_SUCCESS = "success";
    //Row is your bean
     ArrayList<Row> productsList;
    // products JSONArray
    JSONArray products = null;
    JSONParser jParser = new JSONParser();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        new LoadAllProducts().execute();
    }

    /**
     * Background Async Task
     * */
    class LoadAllProducts extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            // do something
        }

        protected String doInBackground(String... args) {

            JSONObject json = jParser.makeHttpRequest(url_all_products, "GET");

            try {

                success = json.getInt(TAG_SUCCESS);

                if (success == 1) {

                    products = json.getJSONArray("OK");

                    productsList = new ArrayList<Row>();

                    // looping through All Products
                    for (int i = 0; i < products.length(); i++) {
                        JSONObject c = products.getJSONObject(i);

                        Row r = new Row();
                        r.setDescription(c.getString("tavolo"));
                        r.setLat(c.getString("pizza"));
                        r.setLon(c.getString("quantita"));
                        r.setGame_sequence(c.getString("note"));

                        productsList.add(r);
                    }
                }else {/*do something*/}
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }
        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // do something

            }
        }
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
public class JSONParser {
    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";
    // constructor
    public JSONParser() {
    }
    // function get json from url
    // by making HTTP POST or GET mehtod
    public JSONObject makeHttpRequest(String url, String method) {
        // Making HTTP request
        try {
            // check for request method
            if("POST".equals(method)){
                // request method is POST
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }else if("GET".equals(method)){
                // request method is GET
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpGet httpGet = new HttpGet(url);
                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is));
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
         e.printStackTrace();
        }
        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
             e.printStackTrace();
        }
        return jObj;
    }
}

@Model(className="RepositoryInfo", properties = {
    @Property(name = "id", type = int.class),
    @Property(name = "name", type = String.class),
    @Property(name = "owner", type = Owner.class),
    @Property(name = "private", type = boolean.class),
})
final class RepositoryCntrl {
    @Model(className = "Owner", properties = {
        @Property(name = "login", type = String.class)
    })
    static final class OwnerCntrl {
    }
}

List<RepositoryInfo> repositories = new ArrayList<>();
try (InputStream is = initializeStream(args)) {
    Models.parse(CONTEXT, RepositoryInfo.class, is, repositories);
}

System.err.println("there is " + repositories.size() + " repositories");
repositories.stream().filter((repo) -> repo != null).forEach((repo) -> {
    System.err.println("repository " + repo.getName() +
        " is owned by " + repo.getOwner().getLogin()
    );
})