Android系统API提供了FileObserver抽象类（Linux的INotify机制）来监听系统/sdcard中的文件或文件夹，FileObserver类能对sdcard中的文件及文件夹的打开、创建、移动和删除操作进行监控。下面看看代码实现：
package com.orgcent.filelistener;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.FileObserver;
public class AndroidFileListenerActivity
extends Activity {
private FileObserver mFileObserver;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
if(null
== mFileObserver)
{
mFileObserver = new SDCardFileObserver(Environment.getExternalStorageDirectory().getPath());
mFileObserver.startWatching();
//开始监听
}
}
public void onDestory()
{
if(null
!= mFileObserver) mFileObserver.stopWatching();
//停止监听
}
static class SDCardFileObserver
extends FileObserver {
//mask:指定要监听的事件类型，默认为FileObserver.ALL_EVENTS
public SDCardFileObserver(String path,
int mask) {
super(path, mask);
}
public SDCardFileObserver(String path)
{
super(path);
}
@Override
public void onEvent(int event,
String path)
{
final int action
= event & FileObserver.ALL_EVENTS;
switch (action)
{
case FileObserver.ACCESS:
System.out.println("event: 文件或目录被访问, path: "
+ path);
break;
case FileObserver.DELETE:
System.out.println("event: 文件或目录被删除, path: "
+ path);
break;
case FileObserver.OPEN:
System.out.println("event: 文件或目录被打开, path: "
+ path);
break;
case FileObserver.MODIFY:
System.out.println("event: 文件或目录被修改, path: "
+ path);
break;
}
}
}
}