Parsing JSON data from text file

Question

Hi I have Java class which will read &parse the JSON data from file and insert into DB,they are storing NAME,AGE and PHONE. The program is working fine;But my requirement is ,I have a different JSON data which needs to do same operation,I want to store AGE , ID and TYPE .I have mentioned my JSON data in the last part

I got this code from the https://javapages4all.wordpress.com/2012/12/10/read-from-json-file-and-persist-into-mysql/

test.json:

{'profiles':[
{'name':'Girish', 'age': 44, 'phone':'203-203-2030'},
{'name':'Alex','age':31, 'phone':'203-203-2030'},
{'name':'Amy', 'age': 24, 'phone':'203-203-2030'},
{'name':'Melissa','age':21, 'phone':'203-203-2030'}
]
}

Java Class:

package com.sample.json;


import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import org.apache.commons.io.IOUtils;

public class MyJson {
    private static String tableName = "jsontest";

    public static void main(String[] args) {
        try {
            ClassLoader cl = MyJson.class.getClassLoader();
            InputStream is = cl.getResourceAsStream("test.json");
            String str = IOUtils.toString(is);
            JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str);
            System.out.println(jsonObject);
            JSONArray jsonArr = jsonObject.getJSONArray("profiles");
            JSONObject obj = null;
            JSONArray nameArr = null;
            JSONArray valArr = null;

            for (int i = 0; i < jsonArr.size(); i++) {
                obj = jsonArr.getJSONObject(i);
                nameArr = obj.names();
                valArr = obj.toJSONArray(nameArr);
                //saveRecord(nameArr, valArr);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void saveRecord(JSONArray nameArray, JSONArray valArray) {
        Connection conn = getConnection();
        StringBuffer sb = new StringBuffer("insert into " + tableName + "(");
        int size = nameArray.size();
        int count = 0;
        Iterator<Object> iterator = nameArray.iterator();

        while (iterator.hasNext()) {
            if (count < (size - 1))
                sb.append(iterator.next() + ",");
            else
                sb.append(iterator.next() + ")");
            count++;
        }
        sb.append(" values(");

        for (int i = 0; i < size; i++) {
            if (i < (size - 1))
                sb.append("?,");
            else
                sb.append("?)");
        }
        System.out.println(sb.toString());
        try {
            PreparedStatement pstmt = conn.prepareStatement(sb.toString());
            bindVariables(valArray, pstmt);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private static void bindVariables(JSONArray valArray,
            PreparedStatement pstmt) throws SQLException {
        Iterator<Object> iterator = valArray.iterator();
        int cnt = 0;
        while (iterator.hasNext()) {
            Object obj = iterator.next();
            if (obj instanceof String) {
                pstmt.setString(++cnt, (String) obj);
            } else if (obj instanceof Integer) {
                pstmt.setLong(++cnt, (Integer) obj);
            } else if (obj instanceof Long) {
                pstmt.setLong(++cnt, (Long) obj);
            } else if (obj instanceof Double) {
                pstmt.setDouble(++cnt, (Double) obj);
            }
        }
    }

    private static Connection getConnection() {
        Connection con = null;
        String url = "jdbc:mysql://localhost:3306/";
        String db = "jsondata";
        String driver = "com.mysql.jdbc.Driver";
        String user = "root";
        String pass = "root";
        try {
            Class.forName(driver);
            con = DriverManager.getConnection(url + db, user, pass);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return con;
    }
}

My JSON:

[{"emp":{"age":34,"ID":3423423},"type":"s"}, 
{"emp":{"age":43,"ID":324324235},"type":"s"}, 
{"emp":{"age":36,"ID":324324236},"type":"v"},
{"emp":{"age":46,"ID":324324238},"type":"s"},
{"emp":{"age":55,"ID":324324243},"type":"s"},
{"emp":{"age":44,"ID":324324287},"type":"s"}]

for the above program i want to use this JSON data

Answer 1

I made a simple example for your case using Gson for parsing json .

public class Result {
    private long id;
    private int age;
    private String type;

    public Result(long id, int age, String type) {
        this.age = age;
        this.id = id;
        this.type = type;
    }
}

public class EmployeeInfo {
    private int age;
    @SerializedName("ID")
    private long id;

    public EmployeeInfo(int age, long id) {
        this.age = age;
        this.id = id;
    }
}

public class Employee {
    @SerializedName("emp")
    private EmployeeInfo employeeInfo;
    private String type;

    public Employee(EmployeeInfo employeeInfo, String type) {
        this.employeeInfo = employeeInfo;
        this.type = type;
    }
}

Run:

public static void main(String[] args) throws IOException {
    String json = "[{\"emp\":{\"age\":34,\"ID\":3423423},\"type\":\"s\"}, \n" +
            "{\"emp\":{\"age\":43,\"ID\":324324235},\"type\":\"s\"}, \n" +
            "{\"emp\":{\"age\":36,\"ID\":324324236},\"type\":\"v\"},\n" +
            "{\"emp\":{\"age\":46,\"ID\":324324238},\"type\":\"s\"},\n" +
            "{\"emp\":{\"age\":55,\"ID\":324324243},\"type\":\"s\"},\n" +
            "{\"emp\":{\"age\":44,\"ID\":324324287},\"type\":\"s\"}]";

    Gson gson = new Gson();
    Type type = new TypeToken<List<Employee>>() {
    }.getType();
    List<Employee> employees = gson.fromJson(json, type);
    List<Result> results = new ArrayList<>();

    Result result;
    for (Employee employee : employees) {
        result = new Result(employee.getEmployeeInfo().getId(), employee.getEmployeeInfo().getAge(), employee.getType());

        results.add(result);
    }

    System.out.println(gson.toJson(results));

}

Answer 2

To do that you must first pars it and save its values somewhere then create a JSON object with desired format and set its values by parsed values from first stage. for example in Android/Java:

ArrayList<YourDataNode> arrayList = new ArrayList<>();
    for (int i=0 ; i<jsonArray.length() ; i++) {
        JSONObject jsonObject = jsonArray.get(i);
        JSONObject empObject = jsonObject.getJSONObject("emp");
        String type = jsonObject.getString("type");
        int age = empObject.getInt("age");
        long id = empObject.getLong("id");
        YourDataNode temp = new (id, age, type);
        arrayList.add(temp);
    }

Answer 3

Try this

import org.codehaus.jettison.json.JSONArray;
import org.codehaus.jettison.json.JSONException;
import org.codehaus.jettison.json.JSONObject;

public class GetDataFromJSON {
public static void main(String[] args) {
    String json = "[{\"emp\":{\"age\":34,\"ID\":3423423},\"type\":\"s\"},"
            + "{\"emp\":{\"age\":43,\"ID\":324324235},\"type\":\"s\"},"
            + "{\"emp\":{\"age\":36,\"ID\":324324236},\"type\":\"v\"},"
            + "{\"emp\":{\"age\":46,\"ID\":324324238},\"type\":\"s\"},"
            + "{\"emp\":{\"age\":55,\"ID\":324324243},\"type\":\"s\"},"
            + "{\"emp\":{\"age\":44,\"ID\":324324287},\"type\":\"s\"}]";
    JSONArray jsonArray = getDesiredJSONArray(json);
    System.out.println(jsonArray);
}

public static JSONArray getDesiredJSONArray(String json) {
    JSONArray jsonArray = null;
    JSONArray desiredJsonArray = new JSONArray();
    try {
        jsonArray = new JSONArray(json);
        for (int i = 0; i < jsonArray.length(); i++) {
            // System.out.println(jsonArray.get(i));
            JSONObject object = new JSONObject(jsonArray.get(i).toString());
            JSONObject jsonObject = new JSONObject();
            jsonObject.put("type", object.get("type"));
            object = new JSONObject(object.get("emp").toString());
            jsonObject.put("ID", object.get("ID"));
            jsonObject.put("age", object.get("age"));
            desiredJsonArray.put(jsonObject);
        }
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return desiredJsonArray;
}
}