How can i retrieve data from database and pass that data into next activity

Question

how should i post this one in next activity by clicking the button Retrieve

But i dont know how to code this one and im using online database 000webhost. my problem is when i click the button retrieve it will post the content of database in next activity which is print.class from MainActivity.class this is my code as far

MainActivity.class

package com.example.child.retrieve;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import com.android.volley.NetworkResponse;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.ServerError;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.HttpHeaderParser;
import com.android.volley.toolbox.Volley;
import com.example.child.retrieve.LoginRequest;
import com.example.child.retrieve.R;
import com.example.child.retrieve.print;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.UnsupportedEncodingException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final Button bLogin = (Button)findViewById(R.id.ret);


        bLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                Response.Listener<String> responseListener = new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {

                        try {
                            JSONObject jsonResponse = new JSONObject(response);
                            boolean success = jsonResponse.getBoolean("success");

                            if(success) {

                                Intent intent = new Intent(MainActivity.this, print.class);
                                MainActivity.this.startActivity(intent);


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

                    }
                };


                LoginRequest loginRequest = new LoginRequest(responseListener);
                RequestQueue queue = Volley.newRequestQueue(MainActivity.this);
                queue.add(loginRequest);

            }
        });
    }


    /* import com.android.volley.toolbox.HttpHeaderParser; */
    public void onErrorResponse(VolleyError error) {

        // As of f605da3 the following should work
        NetworkResponse response = error.networkResponse;
        if (error instanceof ServerError && response != null) {
            try {
                String res = new String(response.data,
                        HttpHeaderParser.parseCharset(response.headers, "utf-8"));
                // Now you can use any deserializer to make sense of data
                JSONObject obj = new JSONObject(res);
            } catch (UnsupportedEncodingException e1) {
                // Couldn't properly decode data to string
                e1.printStackTrace();
            } catch (JSONException e2) {
                // returned data is not JSONObject?
                e2.printStackTrace();
            }
        }
    }
}

MainActivity.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.child.retrieve.MainActivity">

    <Button
        android:id="@+id/ret"
        android:text="Retrieve"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</android.support.constraint.ConstraintLayout>

The LoginRequest.class which is the database is being loaded

package com.example.child.retrieve;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by Child on 1/31/2017.
 */

public class LoginRequest extends StringRequest {

    private static final String LOGIN_REQUEST_URL = "http://cedportfolio.000webhostapp.com/Login.php";
    private Map<String, String> params;

    public LoginRequest(Response.Listener<String> listener) {
        super(Request.Method.POST, LOGIN_REQUEST_URL, listener, null);
        params = new HashMap<>();

    }
    @Override
    public Map<String, String> getParams() {

        return params;
    }
}

print.class

package com.example.child.retrieve;

import android.app.Activity;
import android.os.Bundle;

/**
 * Created by Child on 7/21/2017.
 */

public class print extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.print);
    }
}

A login returning lots of data? Meh. Better return a token and use that token to retrieve data. Also, storing plain passwords? Really? You should hash them before storing. You know, security and that stuff — Alberto S., Jul 21 '17 at 06:17
nah just an example thats not a reality database its for school purposes — jerome, Jul 21 '17 at 07:00
Take a look at this answer: https://stackoverflow.com/questions/2091465/how-do-i-pass-data-between-activities-in-android-application — mbo, Jul 21 '17 at 08:00
Possible duplicate of [How do I pass data between Activities in Android application?](https://stackoverflow.com/questions/2091465/how-do-i-pass-data-between-activities-in-android-application) — mbo, Jul 21 '17 at 08:00

score 1 · Answer 1 · answered Jul 21 '17 at 07:57

1

If you want to pass data from one activity to other you need to create a Parcelable object. Check this answer

You will nedd something like this:

public class MyData implements Parcelable {
    ...
}

Parse the response and pass it to the new activity

MyData data = parseJson(jsonResponse)
Intent intent = new Intent(MainActivity.this, print.class);
intent.putParcelable("data", data);
MainActivity.this.startActivity(intent);

Recover it at the new activity

public class print extends Activity {

    ...
    MyData data = getIntent().getParcelableExtra("data");
    ...
}

Beware that passing big objects between activities may have performance penalties. You should consider other strategies like passing some IDs and fetching the data at the "receiver" activity

answered Jul 21 '17 at 07:57

Alberto S.

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the data is not in the current activity. the data is came from the database. so that if i click retrieve button. the picture above will post to the print.class – jerome Jul 21 '17 at 08:03
What do you mean by "the picture above will post to the print.class"? – Alberto S. Jul 21 '17 at 09:37
yes its my database. i want to print all that content in the print.class – jerome Jul 21 '17 at 11:32
Then your server will need an endpoint that returns you the data you need – Alberto S. Jul 21 '17 at 11:42

How can i retrieve data from database and pass that data into next activity

1 Answers1