安卓笔记之File保存数据

package com.example.day0330_file;

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

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    private Button button1,button2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button1 = (Button) findViewById(R.id.bt1);
        button2 = (Button) findViewById(R.id.bt2);
        button1.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                //把数据保存到文件中
                try {
                    //打开文件输出流用来写入数据
                    OutputStream os = openFileOutput("file.txt", MODE_PRIVATE);
                    os.write("123".getBytes());
                    os.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        button2.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // 读取文件
                try {
                    //打开文件输入流用来读取数据
                    InputStream is = openFileInput("file.txt");
                    byte[] bys = new byte[1024];
                    int len = 0;
                    while((len=is.read(bys))!=-1){
                        //在LogCat打印出来
                        Log.i("button2", new String(bys, 0, len));
                    }
                    is.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}