Client Androïd JWT

Cet article est la suite de l’article Token JWT.

Dans cet article nous allons voir l’implémentation d’un token JWT afin de sécurisé notre exemple de gestion de produit.

Param.java :

package org.libreapps.rest;

public class Param {
    private String token;
    private static Param param;

    private Param() {
    }

    public static Param getInstance() {
        if (param == null) {
            param = new Param();
        }
        return param;
    }

    public void setToken(String token) { this.token = token; }

    public String getToken() { return token; }
}

LoginActivity.java :

package org.libreapps.rest;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

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

import java.util.concurrent.ExecutionException;

public class LoginActivity extends AppCompatActivity {
    private EditText userEmail;
    private EditText userPassword;
    private Button buttonLogin;
    private Button buttonRegister;

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

        userEmail = (EditText)findViewById(R.id.user_email);
        userPassword = (EditText)findViewById(R.id.user_password);
        buttonLogin = (Button)findViewById(R.id.button_login);

        userEmail.setText("");
        userPassword.setText("");

        buttonLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            try {
                JSONObject jAuth = new JSONObject();
                jAuth.put("email", userEmail.getText().toString());
                jAuth.put("password", userPassword.getText().toString());
                jAuth.put("app", "MNA");

                Log.v("LoginActivity", userEmail.getText().toString()+" "+userPassword.getText().toString());
                ConnectionRest connectionRest = new ConnectionRest();
                connectionRest.setObj(jAuth);
                connectionRest.setAction("auth");
                connectionRest.execute("POST");
                String token = connectionRest.get();
                Param.getInstance().setToken(token);

                if(token.charAt(0)=='{') {
                    Log.v("LoginActivity", token);
                }else{
                    Param.getInstance().setToken(token);
                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);             
                    startActivity(intent);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            } catch (InterruptedException  e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
            }
        });
    }
}

activity_login.xml :

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".LoginActivity">

    <EditText
        android:id="@+id/user_email"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="E-Mail"
        android:inputType="textEmailAddress"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.339" />

    <EditText
        android:id="@+id/user_password"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="Password"
        android:inputType="textPassword"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.425" />

    <Button
        android:id="@+id/button_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="56dp"
        android:text="CONNECTION"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.484" />


</androidx.constraintlayout.widget.ConstraintLayout>

ConnectionRest.java :

package org.libreapps.rest;

import android.os.AsyncTask;
import android.util.Log;

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

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;

public class ConnectionRest extends AsyncTask<String, Void, String> {
    private final static String URL = "<URL>";
    private JSONObject jsonObj = null;
    private String action = "product";

    @Override
    protected String doInBackground(String... strings) {
        try {
            return get(strings[0]);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }

    public String get(String methode) throws IOException, JSONException {
        String url = URL + action + "/";
        String token = Param.getInstance().getToken();
        InputStream is = null;
        String parameters = "";
        if(!methode.equals("POST")&&(jsonObj!=null)){
            url += jsonObj.getInt("id");
        }
        if(jsonObj != null){
            if(methode.equals("PUT")){
                jsonObj.remove("id");
            }
            parameters  = "data="+URLEncoder.encode(jsonObj.toString(), "utf-8");
            //Log.v("URL", url+" "+parameters);
        }

        try {
            final HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod(methode);
            if (token != null) {
                conn.setRequestProperty("Authorization", "Bearer " + URLEncoder.encode(token, "utf-8"));
            }

            // Pour les methode POST et PUT on envoie les parametre avec l'OutputStreamWriter
            if(methode.equals("POST")||methode.equals("PUT")){
                conn.setDoInput(true);
                conn.setDoOutput(true);
                OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
                out.write(parameters);// here i sent the parameter
                out.close();
            }else{
                conn.setDoInput(true);
                conn.connect();
            }

            is = conn.getInputStream();
            // Lit le InputStream et l'enregistre dans une string
            return readIt(is);
        } finally {
            // Pour etre sur que le InputStream soit ferme apres avoir quitter l'application
            if (is != null) {
                is.close();
            }
        }
    }

    private String readIt(InputStream is) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(is));
        StringBuilder response = new StringBuilder();
        String line;
        while ((line = r.readLine()) != null) {
            response.append(line).append('\n');
        }
        return response.toString();
    }

    public ArrayList<Product> parse(final String json) {
        try {
            final ArrayList<Product> products = new ArrayList<>();
            final JSONArray jProductArray = new JSONArray(json);
            for (int i = 0; i < jProductArray.length(); i++) {
                products.add(new Product(jProductArray.optJSONObject(i)));
            }
            return products;
        } catch (JSONException e) {
            Log.v("TAG","[JSONException] e : " + e.getMessage());
        }
        return null;
    }

    public void setObj(JSONObject jsonObj){
        this.jsonObj = jsonObj;
    }
    public void setAction(String monAction){ this.action = monAction;}

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
    }
}

La suite : Enregistrement d’un client Android

Code source : https://github.com/emunier/Rest-jwt.git

Sources :