Question

Can you fix these errors in Android Studio?

What I am trying to do is that developing an app to document the lifecycle of an “activity”.

-------------------------------

AppDocumentationActivity.java:

---------------------------------------

package com.example.activity_docmentation;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

public class AppDocumentationActivity extends AppCompatActivity {

    String message = getResources().getString(R.string.app_lifecycle_log); //Logcat tag
    String mActivityState; //refers to some state of activity
    int instanceTimes; //number of times instance is called
    String ACTIVITY_STATE_KEY;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //recover instance state
        if(savedInstanceState!=null)
        {
            mActivityState = savedInstanceState.getString(ACTIVITY_STATE_KEY);
        }
        else
        {
            instanceTimes=0;
            ACTIVITY_STATE_KEY="";
        }

        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        //logs event message
        String eventMessage=getResources().getString(R.string.on_create_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);            
        Log.d(message,savedInstanceState.getString(ACTIVITY_STATE_KEY));

    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        instanceTimes++;
        mActivityState=String.valueOf(instanceTimes);

        outState.putString(ACTIVITY_STATE_KEY,mActivityState);

        super.onSaveInstanceState(outState);
    }

    /**
     * Dispatch onStart() to all fragments.  Ensure any created loaders are
     * now started.
     */
    @Override
    protected void onStart() {
        super.onStart();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_start_str);
        Log.d(message,eventMessage);
    }

    /**
     * Dispatch onResume() to fragments.  Note that for better inter-operation
     * with older versions of the platform, at the point of this call the
     * fragments attached to the activity are <em>not</em> resumed.  This means
     * that in some cases the previous state may still be saved, not allowing
     * fragment transactions that modify the state.  To correctly interact
     * with fragments in their proper state, you should instead override
     * {@link #onResumeFragments()}.
     */
    @Override
    protected void onResume() {
        super.onResume();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_resume_str);
        Log.d(message,eventMessage);
    }

    /**
     * Dispatch onPause() to fragments.
     */
    @Override
    protected void onPause() {
        super.onPause();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_pause_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onStop() {
        super.onStop();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_stop_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_destroy_str);
        Log.d(message,eventMessage);
    }

    /*@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }*/
}

----------------------------------------

strings.xml:

---------------------------------------

<resources>
    <string name="app_name">Activity_docmentation</string>
    <string name="app_str">Activity_docmentation</string>
    <string name="app_lifecycle_log">Activity Lifecycle log:</string>
    <string name="on_create_str">onCreate() method</string>
    <string name="on_start_str">onStart() method</string>
    <string name="on_resume_str">onResume() method</string>
    <string name="on_pause_str">onPause() method</string>
    <string name="on_stop_str">onStop() method</string>
    <string name="on_destroy_str">onDestroy() method</string>
    <string name="action_settings">Settings</string>
</resources>

Answer 1

package com.example.activity_documentation;


import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

public class AppDocumentationActivity extends AppCompatActivity {

    String message;
    String mActivityState; //refers to some state of activity
    int instanceTimes; //number of times instance is called
    String ACTIVITY_STATE_KEY;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // get the message inside the onCreate
        message = getResources().getString(R.string.app_lifecycle_log); //Logcat tag

        //recover instance state
        if(savedInstanceState!=null)
        {
            mActivityState = savedInstanceState.getString(ACTIVITY_STATE_KEY);
        }
        else
        {
            instanceTimes=0;
            ACTIVITY_STATE_KEY="";
        }

        setContentView(R.layout.activity_main);

       Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
       setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                       .setAction("Action", null).show();
            }
        });

        //logs event message
        String eventMessage=getResources().getString(R.string.on_create_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        Log.d(message,savedInstanceState.getString(ACTIVITY_STATE_KEY));
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        instanceTimes++;
        mActivityState=String.valueOf(instanceTimes);

        outState.putString(ACTIVITY_STATE_KEY,mActivityState);

        super.onSaveInstanceState(outState);
    }

    /**
     * Dispatch onStart() to all fragments. Ensure any created loaders are
     * now started.
     */
    @Override
    protected void onStart() {
        super.onStart();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_start_str);
        Log.d(message,eventMessage);
    }

    /**
     * Dispatch onResume() to fragments. Note that for better inter-operation
     * with older versions of the platform, at the point of this call the
     * fragments attached to the activity are <em>not</em> resumed. This means
   * that in some cases the previous state may still be saved, not allowing
     * fragment transactions that modify the state. To correctly interact
     * with fragments in their proper state, you should instead override
     * {@link #onResumeFragments()}.
     */
    @Override
    protected void onResume() {
        super.onResume();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_resume_str);
        Log.d(message,eventMessage);
    }

    /**
     * Dispatch onPause() to fragments.
     */
    @Override
    protected void onPause() {
        super.onPause();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_pause_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onStop() {
        super.onStop();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_stop_str);
        Log.d(message,eventMessage);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //logs event message
        String eventMessage=getResources().getString(R.string.on_destroy_str);
        Log.d(message,eventMessage);
    }

       /*@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }*/
}

----------------------------------------

strings.xml:

---------------------------------------

<resources>
    <string name="app_name">Activity_docmentation</string>
    <string name="app_str">Activity_docmentation</string>
    <string name="app_lifecycle_log">Activity Lifecycle log:</string>
    <string name="on_create_str">onCreate() method</string>
    <string name="on_start_str">onStart() method</string>
    <string name="on_resume_str">onResume() method</string>
    <string name="on_pause_str">onPause() method</string>
    <string name="on_stop_str">onStop() method</string>
    <string name="on_destroy_str">onDestroy() method</string>
    <string name="action_settings">Settings</string>
</resources>

Logcat statements: