Encode dan Decode JSON Data dengan Java

CREATE DATABASE /*!32312 IF NOT EXISTS*/`bukubase` /*!40100 DEFAULT CHARACTER SET latin1 */;

USE `bukubase`;

/*Table structure for table `daftar_buku` */

DROP TABLE IF EXISTS `daftar_buku`;

CREATE TABLE `daftar_buku` (
  `buku_kode` int(11) NOT NULL,
  `buku_judul` varchar(100) DEFAULT NULL,
  `buku_penerbit` varchar(100) DEFAULT NULL,
  `buku_tahun` year(4) DEFAULT NULL,
  PRIMARY KEY (`buku_kode`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

/*Data for the table `daftar_buku` */

insert  into `daftar_buku`(`buku_kode`,`buku_judul`,`buku_penerbit`,`buku_tahun`) values (1,'Wordpress Advanced','Neomedia',2001),(2,'PHP For Evil Genius','Socka Inc.',1999),(3,'Linux Kernel For Breakfast','Socka Inc.',2009),(4,'Play With Perl Undercover for Evil genius','Socka Inc.',2009),(5,'Android Cook Book For Mother','Dopler Crook',2008);

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.LinkedHashMap;
import org.json.simple.*;
import org.json.simple.parser.JSONParser;

/**
 *
 * @author x86, haripinter in case :P
 * 
 */
public class Json {

    /**
     * @param args the command line arguments
     */

    // class untuk pengumpulan data sebelum diencode ke format JSON
    // input : String[] key -> String[] value
    static class pushdata implements JSONStreamAware{
        private String[] key;
        private String[] value;

        public pushdata(String[] key, String[] value){
            this.value = value;
            this.key  = key;
        }

        public void writeJSONString(Writer writer) throws IOException {
            LinkedHashMap obj = new LinkedHashMap();
            for(int i=0; i<key.length; i++){
                obj.put(key[i], value[i]);
            }
            JSONValue.writeJSONString(obj, writer);
        }
    }

    public static void main(String[] args) {
        String host = "localhost";
        String debe = "bukubase";
        String user = "root";
        String pass = "";
        Connection con = null;
        Statement sta = null;
        try{
            Class.forName("org.gjt.mm.mysql.Driver");
            con = DriverManager.getConnection("jdbc:mysql://"+host+"/"+debe,user,pass);
            sta = con.createStatement();
        }catch(Exception e){
        }

        try{
            System.out.println("====================================");
            System.out.println("Sebelum diencode menjadi format JSON");
            System.out.println("====================================");
            // inisialisasi JSONArray dan pengambilan data dari database
            JSONArray js = new JSONArray();
            ResultSet res = sta.executeQuery("select * from daftar_buku order by buku_kode");
            while(res.next()){
                //cetak sebelum mnejadi string JSON
                System.out.println(res.getString("buku_kode"));
                System.out.println(res.getString("buku_judul"));
                System.out.println(res.getString("buku_penerbit"));
                System.out.println(res.getString("buku_tahun"));

                // membuat key dan value untuk dipush ke json
                String[] key = {
                    "buku_kode",
                    "buku_judul",
                    "buku_penerbit",
                    "buku_tahun"
                };
                String[] value = {
                    res.getString("buku_kode"),
                    res.getString("buku_judul"),
                    res.getString("buku_penerbit"),
                    res.getString("buku_tahun")
                };

                // kelompokkan data untuk dibuat json
                js.add(new pushdata(key,value));
            }

            // encode ke format JSON
            StringWriter hasil = new StringWriter();
            js.writeJSONString(hasil);
            String jsons = hasil.toString();

            System.out.println();
            System.out.println("====================================");
            System.out.println("Setelah diencode menjadi format JSON");
            System.out.println("====================================");
            System.out.println(jsons);
            System.out.println();

            // decode json array
            // inisialisasi dengan memparsing array JSON
            JSONParser jpars = new JSONParser();
            Object object = jpars.parse(jsons);
            // JSON dijadikan array objek kemudian kita ambil datanya
            System.out.println("====================================");
            System.out.println("Setelah didecode menjadi format biasa");
            System.out.println("====================================");
            JSONArray jsonArr = (JSONArray) object;
            for(int i=0; i<jsonArr.size(); i++){
                // ekstraksi array objek, menjadi objek...
                JSONObject obj = (JSONObject) jsonArr.get(i);
                System.out.println(obj.get("buku_kode"));
                System.out.println(obj.get("buku_judul"));
                System.out.println(obj.get("buku_penerbit"));
                System.out.println(obj.get("buku_tahun"));
            }
        }catch(Exception e){

        }
    }
}

run:
====================================
Sebelum diencode menjadi format JSON
====================================
1
Wordpress Advanced
Neomedia
2001-01-01
2
PHP For Evil Genius
Socka Inc.
1999-01-01
3
Linux Kernel For Breakfast
Socka Inc.
2009-01-01
4
Play With Perl Undercover for Evil genius
Socka Inc.
2009-01-01
5
Android Cook Book For Mother
Dopler Crook
2008-01-01

====================================
Setelah diencode menjadi format JSON
====================================
[{"buku_kode":"1","buku_judul":"Wordpress Advanced","buku_penerbit":"Neomedia","buku_tahun":"2001-01-01"},{"buku_kode":"2","buku_judul":"PHP For Evil Genius","buku_penerbit":"Socka Inc.","buku_tahun":"1999-01-01"},{"buku_kode":"3","buku_judul":"Linux Kernel For Breakfast","buku_penerbit":"Socka Inc.","buku_tahun":"2009-01-01"},{"buku_kode":"4","buku_judul":"Play With Perl Undercover for Evil genius","buku_penerbit":"Socka Inc.","buku_tahun":"2009-01-01"},{"buku_kode":"5","buku_judul":"Android Cook Book For Mother","buku_penerbit":"Dopler Crook","buku_tahun":"2008-01-01"}]

====================================
Setelah didecode menjadi format biasa
====================================
1
Wordpress Advanced
Neomedia
2001-01-01
2
PHP For Evil Genius
Socka Inc.
1999-01-01
3
Linux Kernel For Breakfast
Socka Inc.
2009-01-01
4
Play With Perl Undercover for Evil genius
Socka Inc.
2009-01-01
5
Android Cook Book For Mother
Dopler Crook
2008-01-01
BUILD SUCCESSFUL (total time: 1 second)