データストレージのファイルストレージ——第1行コードAndroid学習ノート

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <EditText
        android:id="@+id/edit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="   "/>
</LinearLayout>

<span style="font-weight: normal;">package com.example.filepersistencetest;

import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;


public class MainActivity extends Activity {
	private EditText edit;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        edit=(EditText)findViewById(R.id.edit);
    }

    @Override
    protected void onDestroy() {
    	// TODO Auto-generated method stub
    	super.onDestroy();
    	String inputText=edit.getText().toString();
    	save(inputText);
    }
    
    public void save(String inputText){
    	FileOutputStream out = null;
    	BufferedWriter writer = null;
    	try{
    		out=openFileOutput("data", Context.MODE_PRIVATE);
    		writer= new BufferedWriter(new OutputStreamWriter(out));
    		writer.write(inputText);
    	}catch(IOException e){
    		e.printStackTrace();
    	}finally{
    		try{
    			if(writer!=null){
    				writer.close();
    			}
    		}catch(IOException e){
    			e.printStackTrace();
    		}
    	}
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}</span>

<span style="font-weight: normal;">    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        edit=(EditText)findViewById(R.id.edit);
        String inputText=load();
        if(!TextUtils.isEmpty(inputText)){
        	edit.setText(inputText);
        	edit.setSelection(inputText.length());
        	Toast.makeText(this, "Restoring succeeded", Toast.LENGTH_SHORT).show();
        }
    }</span>

<span style="font-weight: normal;">    public String load() {
    	FileInputStream in = null;
    	BufferedReader reader = null;
    	StringBuilder content = new StringBuilder();
    	try {
			in= openFileInput("data");
			reader= new BufferedReader(new InputStreamReader(in));
			String line = "";
			while((line=reader.readLine())!=null){
				content.append(line);
			}
		} catch (IOException e) {
			// TODO: handle exception
			e.printStackTrace();
		}finally{
			if(reader!=null){
				try {
					reader.close();
				} catch (IOException e) {
					// TODO: handle exception
					e.printStackTrace();
				}
			}
		}
    	return content.toString();
    }</span>