DevService

app/src/main/AndroidManifest.xml

@@ -3,6 +3,8 @@
     package="com.example.anna.myapplication">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 
     <application
         android:name=".presentation.MyApplication"
@@ -26,7 +28,13 @@
         <activity android:name=".presentation.CatAsyncTaskActivity" />
         <activity android:name=".presentation.FrescoImageActivity" />
         <activity android:name=".presentation.SQLiteDBActivity" />
-        <activity android:name=".presentation.RoomDB"></activity>
+        <activity android:name=".presentation.RoomDB" />
+
+        <service
+            android:name=".data.LoadDatabaseIntentService"
+            android:exported="false" />
+
+        <activity android:name=".presentation.IntentServiceActivity"></activity>
     </application>
 
 </manifest>

app/src/main/java/com/example/anna/myapplication/data/LoadDatabaseIntentService.java

@@ -0,0 +1,36 @@
+package com.example.anna.myapplication.data;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+
+import android.app.IntentService;
+import android.content.Context;
+import android.content.Intent;
+import android.widget.Toast;
+
+import com.example.anna.myapplication.presentation.MyApplication;
+
+public class LoadDatabaseIntentService extends IntentService {
+
+    private FileOutputStream fileOutputStream = null;
+
+    public LoadDatabaseIntentService() {
+        super("LoadDatabaseIntentService");
+    }
+
+    @Override
+    protected void onHandleIntent(Intent intent) {
+        if (intent != null) {
+            String databaseBackup = MyApplication.getPersonDao().loadAll().toString();
+            String fileName = intent.getStringExtra("fileName");
+            try {
+                fileOutputStream = openFileOutput(fileName, Context.MODE_PRIVATE);
+                fileOutputStream.write(databaseBackup.getBytes());
+                fileOutputStream.close();
+            } catch (Exception e) {
+                Toast toast = Toast.makeText(this, "An error occurred while writing database", Toast.LENGTH_LONG);
+                toast.show();
+            }
+        }
+    }
+}

app/src/main/java/com/example/anna/myapplication/data/PersonContract.java

@@ -4,7 +4,6 @@
 
 public interface PersonContract extends BaseColumns {
 
-
     String TABLE_NAME = "personsTable";
 
     String NAME = "name";

app/src/main/java/com/example/anna/myapplication/domain/Person.java

@@ -71,11 +71,29 @@ public void setBirthday(String birthday) {
 
     @Override
     public String toString() {
+        String returnedString = "Person{id=";
         if (id == NOT_SPECIFIED_LONG) {
-            return "Person{" + "id=?, name='" + name + "\'" + '}';
+            returnedString = returnedString.concat("?");
         } else {
-            return "Person{" + "id=" + id + ", name='" + name + "\'" + '}';
+            returnedString = returnedString.concat("" + id);
         }
+        if (!name.equals(NOT_SPECIFIED_STRING)) {
+            returnedString = returnedString.concat(", name='" + name + "\'");
+        }
+        if (!note.equals(NOT_SPECIFIED_STRING)) {
+            returnedString = returnedString.concat(", note='" + note + "\'");
+        }
+        if (imageRes != NOT_SPECIFIED_INT) {
+            returnedString = returnedString.concat(", imageRes=" + imageRes);
+        }
+        if (!imageLink.equals(NOT_SPECIFIED_STRING)) {
+            returnedString = returnedString.concat(", imageLink='" + imageLink + "\'");
+        }
+        if (!birthday.equals(NOT_SPECIFIED_STRING)) {
+            returnedString = returnedString.concat(", birthday=" + birthday);
+        }
+        returnedString = returnedString.concat("}");
+        return returnedString;
     }
 }
 

app/src/main/java/com/example/anna/myapplication/presentation/IntentServiceActivity.java

@@ -0,0 +1,41 @@
+package com.example.anna.myapplication.presentation;
+
+import android.support.v7.app.AppCompatActivity;
+import android.os.Bundle;
+import android.widget.Button;
+import android.widget.TextView;
+
+import com.example.anna.myapplication.R;
+
+import java.io.FileInputStream;
+
+public class IntentServiceActivity extends AppCompatActivity {
+
+    private TextView DatabaseTextView;
+    private Button DatabaseLoadButton;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.intent_service);
+
+        DatabaseTextView = (TextView) findViewById(R.id.textView);
+
+        DatabaseLoadButton = (Button) findViewById(R.id.loadDatabaseButton);
+        DatabaseLoadButton.setOnClickListener(view -> {
+            StringBuilder stringBuilder = new StringBuilder();
+            try{
+                FileInputStream fstream = openFileInput(MyApplication.getFileName());
+                int i;
+                while ((i = fstream.read())!= -1){
+                    stringBuilder.append((char)i);
+                }
+                fstream.close();
+                DatabaseTextView.setText(stringBuilder.toString());
+            }catch (Exception e){
+                DatabaseTextView.setText(getResources().getString(R.string.error_load_database));
+            }
+
+        });
+    }
+}

app/src/main/java/com/example/anna/myapplication/presentation/MainActivity.java

@@ -48,7 +48,7 @@ protected void onCreate(Bundle savedInstanceState) {
 
         buttonTraining = findViewById(R.id.training_thread);
         buttonTraining.setOnClickListener(view -> {
-            Intent startActivity = new Intent(MainActivity.this, RoomDB.class);
+            Intent startActivity = new Intent(MainActivity.this, IntentServiceActivity.class);
             startActivity(startActivity);
         });
     }

app/src/main/java/com/example/anna/myapplication/presentation/MyApplication.java

@@ -2,25 +2,39 @@
 
 import android.app.Application;
 import android.arch.persistence.room.Room;
+import android.content.Intent;
 
+import com.example.anna.myapplication.data.LoadDatabaseIntentService;
 import com.example.anna.myapplication.data.AppDatabase;
 import com.example.anna.myapplication.data.DatabaseHolder;
 import com.example.anna.myapplication.data.PersonDao;
 import com.example.anna.myapplication.data.PersonRepository;
 import com.facebook.drawee.backends.pipeline.Fresco;
 
+import java.util.Date;
+
 public class MyApplication extends Application {
 
     private static AppDatabase database;
     private static PersonRepository personRepository;
     private static DatabaseHolder databaseHolder;
+    private static String fileName;
 
     public static PersonDao getPersonDao(){
         return database.PersonDao();
     }
     public static PersonRepository getRepository(){
         return personRepository;
     }
+    public static String getFileName(){
+        return fileName;
+    }
+
+    private String getFileNameOnCurrentTime(){
+        Date currentDate = new Date();
+        long millisFromStart = currentDate.getTime();
+        return "backup-" + millisFromStart;
+    }
 
     @Override
     public void onCreate() {
@@ -36,6 +50,11 @@ public void onCreate() {
                 .build();
 
         setInitialData();
+
+        // Запускаем IntentService
+        Intent intentMyIntentService = new Intent(this, LoadDatabaseIntentService.class);
+        fileName = getFileNameOnCurrentTime();
+        startService(intentMyIntentService.putExtra("fileName", fileName));
     }
 
     public static void setInitialData(){

app/src/main/java/com/example/anna/myapplication/presentation/RoomDB.java

@@ -37,8 +37,8 @@ protected void onCreate(Bundle savedInstanceState) {
 
         nextButton = findViewById(R.id.nextScreenButton);
         nextButton.setOnClickListener(view -> {
-            // Intent startActivity = new Intent(this, RoomDB.class);
-            //startActivity(startActivity);
+            Intent startActivity = new Intent(this, IntentServiceActivity.class);
+            startActivity(startActivity);
         });
 
         backButton = findViewById(R.id.to_first_activity_button);

app/src/main/res/layout/intent_service.xml

@@ -0,0 +1,27 @@
+<?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=".presentation.IntentServiceActivity">
+
+    <Button
+        android:id="@+id/loadDatabaseButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/load_database"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent" />
+
+    <ScrollView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toBottomOf="@+id/loadDatabaseButton">
+        <TextView
+            android:id="@+id/textView"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content" />
+    </ScrollView>
+
+</android.support.constraint.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -16,4 +16,6 @@
     <string name="additional_thread">try everything</string>
     <string name="cat_start">Start the cat</string>
     <string name="next">Next screen</string>
+    <string name="load_database">Load Database</string>
+    <string name="error_load_database">ERROR happened during database showing</string>
 </resources>