Android中的数据存取（二）File

File的存取方法适用于将数据直接以文本的形式保存在设备之中，通过Context.openFileInput()方法获得标准Java文件输入流(FileInputStream),通过Context.openFileOutput()方法获得标准Java文件输出流(FileOutputStream)

下面是具体代码

package com.example.data2;

import java.io.FileInputStream;
import java.io.FileOutputStream;

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

public class MainActivity extends Activity {
    EditText write,read;
    Button writeb,readb;
    private static final String File_name="data2";
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        creatView();
        setlistener1();
        setlistener2();
    }

    private void setlistener2() {
        // TODO Auto-generated method stub
        readb.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                read.setText(read());
                
            }
        });
        
    }

    private void setlistener1() {
        // TODO Auto-generated method stub
        writeb.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                write(write.getText().toString());
            }
        });
        
    }

    private void creatView() {
        // TODO Auto-generated method stub
        write=(EditText)findViewById(R.id.write);
        read=(EditText)findViewById(R.id.read);
        writeb=(Button)findViewById(R.id.writeb);
        readb=(Button)findViewById(R.id.readb);
    }
    private String read(){
        try {
        FileInputStream datain=openFileInput(File_name);
        byte[] buffer=new byte[datain.available()];
        datain.read(buffer);
        return new String(buffer);
        } catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
    private void write(String content){
        try{
            FileOutputStream dataout=openFileOutput(File_name, MODE_APPEND);
            dataout.write(content.getBytes());
            dataout.close();
        }catch (Exception 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.activity_main, menu);
        return true;
    }

}

测试完成