MainActivity.java

package com.applite.internalstorage;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import android.support.v7.app.ActionBarActivity;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity {

	private EditText et;
	
	private Button btnSave;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        et=(EditText)findViewById(R.id.et);
        
        btnSave=(Button)findViewById(R.id.btnSave);
        
        readSavedText();
        
        btnSave.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				saveCurrentText();
			}
		});
    }
    
    private void readSavedText(){
    	try {
    		InputStream is=openFileInput("data");
    		byte[] bytes=new byte[is.available()];
    		is.read(bytes);
    		is.close();
    		
    		String str=new String(bytes, "utf-8");
    		et.setText(str);
    		
		} catch (FileNotFoundException e) {
			// TODO: handle exception
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
    	
    }
    
    private void saveCurrentText(){
    	try {
    		OutputStream os=openFileOutput("data", Context.MODE_PRIVATE);
    		os.write(et.getText().toString().getBytes("utf-8"));
    		os.flush();
    		os.close();
    		
    		Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();
    		return;
    	} catch (FileNotFoundException e) {
			// TODO: handle exception
			e.printStackTrace();
		}
    	catch (UnsupportedEncodingException e) {
			// TODO: handle exception
    		e.printStackTrace();
		}
    	catch (IOException e) {
			// TODO: handle exception
    		e.printStackTrace();
		}
    	Toast.makeText(this, "保存失败", Toast.LENGTH_SHORT).show();
    }


    @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);
    }
}