Android之SD卡上的文件读取

public class ReadSDCard extends Activity
{
String FILE_NAME = "/test1.txt" ;//SD卡的文件的路径
Button writeBtn, readBtn ;
// 一个写的按钮，一个读取的按钮
EditText text1, text2 ;
@Override
protected void onCreate(Bundle
savedInstanceState) {
// TODO Auto-generated
method stub
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_readsdcard);
writeBtn =
(Button) findViewById(R.id.btn_write);
readBtn =
(Button) findViewById(R.id.btn_read);
text1 =
(EditText) findViewById(R.id.edit_t1);
text2 =
(EditText) findViewById(R.id.edit_t2);
writeBtn.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View
v) {
String msg = text1.getText().toString();
writeMSG(msg);
text1.setText("" );
}
});
readBtn.setOnClickListener(new OnClickListener()
{

@Override
public void onClick(View
v) {
try {
//
如果手机插入了SD卡，而且应用程序具有访问SD的权限(要在配置文件中注册)
if (Environment.getExternalStorageState().equals(Environment. MEDIA_MOUNTED))
{
//
获取SD卡对应的存储目录
File sdCardDir = Environment
. getExternalStorageDirectory();
//
获取指定文件对应的输入流
FileInputStream fis = new FileInputStream(sdCardDir
.getCanonicalFile() + FILE_NAME);
//
将制定的流包装秤BufferedReader
BufferedReader br = new BufferedReader(
new InputStreamReader(fis));
StringBuilder sb = new StringBuilder("" );
String line = null;
//
循环读取文件的内容
while ((line
= br.readLine()) != null) {
sb.append(line);
}
br.close();
text2.setText(sb);
}
} catch (FileNotFoundException
e) {
e.printStackTrace();
} catch (IOException
e) {
e.printStackTrace();
}
}
});
}
private void writeMSG(String
content) {
try {
if (Environment.getExternalStorageState().equals(Environment. MEDIA_MOUNTED))
{
//
获取SD卡目录
File sdCard = Environment.getExternalStorageDirectory();
File targeFile = new File(sdCard.getCanonicalFile()
+ FILE_NAME );
//
以指定文件创建RandomAccessFile对象
RandomAccessFile raf = new RandomAccessFile(targeFile, "rw" );
//
将文件记住的指针移动到最后(移到最后才能追加、不然只能覆盖原有的数据)
raf.seek(targeFile.length());
raf.write(content.getBytes());
System. out.println("写入成功" +
raf);
raf.close();
}
} catch (Exception
e) {
}
}
}