初学Android,数据存储之File存储(四十二)

Android提供了如下两个方法来打开本应用程序的数据文件夹里的文件IO流

openFileInput(String name)

openFileOutput(String name)

打开应用程序的数据文件夹下的name文件对应输入/输出流

下面是一个示例

界面代码

package WangLi.IO.FileTest;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.PrintStream;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class FileTest extends Activity {final String FILE_NAME = "test.txt";    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        //获取两个按钮        Button read = (Button)findViewById(R.id.read);        Button write = (Button)findViewById(R.id.write);        //获取两个文本框        final EditText edit1 = (EditText)findViewById(R.id.edit1);        final EditText edit2 = (EditText)findViewById(R.id.edit2);        //为write按钮绑定事件监听器        write.setOnClickListener(new OnClickListener(){        public void onClick(View source)        {        //将edit1中的内容写入文件中        write(edit1.getText().toString());        edit1.setText("");        }        });                read.setOnClickListener(new OnClickListener(){        public void onClick(View source)        {        //读取指定文件中的内容并显示出来        edit2.setText(read());        }        });    }        private String read()    {    try    {    //打开文件件输入流    FileInputStream fis = openFileInput(FILE_NAME);    byte[] buff = new byte[1024];    int hasRead = 0;    StringBuilder sb = new StringBuilder("");    while((hasRead = fis.read(buff)) > 0)    {    sb.append(new String(buff, 0 , hasRead));    }    return sb.toString();    }    catch(Exception e)    {    e.printStackTrace();    }    return null;    }        private void write(String content)    {    try    {    //以追加模式打开文件输出流    FileOutputStream fos = openFileOutput(FILE_NAME,MODE_APPEND);    //将FileOutputStream包装成PrintStream    PrintStream ps = new PrintStream(fos);    //输出文件内容    ps.println(content);    ps.close();    }    catch(Exception e)    {    e.printStackTrace();    }    }}

下图为DDMS里的路径

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