| 有三种方式：
1、java common.io 内部实现是遍历的方式，小文件夹的效率还好，比如我测试60G的目录，就很慢很慢了。
2、jdk 7 的watch service //经测试基本不可用。在一个40g的很深的目录下去新建和删除文件5分钟都没结果。主要原因是需要对每一个Path进行注册监控。
3、jnotify 直接调用windows的api，效率很高，也很简单，推荐使用。
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common.io
需要java.io 2.1及其以上版本。版本地址如下：
http://commons.apache.org/io/download_io.cgi
import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;
/**
* 自定义文件监听器
* @author
* @date 2010-11-16
* @file org.demo.file.MyFileListener.java
*/
public class MyFileListener extends FileAlterationListenerAdaptor{
@Override
public void onFileCreate(File file) {
System.out.println("[新建]:" + file.getAbsolutePath());
}
@Override
public void onFileChange(File file) {
System.out.println("[修改]:" + file.getAbsolutePath());
}
@Override
public void onFileDelete(File file) {
System.out.println("[删除]:" + file.getAbsolutePath());
}
}
import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;
public class Test {
/**
* @param args
*/
public static void main(String[] args) throws Exception{
// 监控目录
String rootDir = "d:\\Temp";
// 轮询间隔 5 毫秒
long interval = 5l;
//
FileAlterationObserver observer = new FileAlterationObserver(
rootDir,null,
null);
observer.addListener(new MyFileListener());
FileAlterationMonitor monitor = new FileAlterationMonitor(interval,observer);
// 开始监控
monitor.start();
}
}
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jdk7 watchservice
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.HashMap;
import java.util.Map;
import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
public class TestWatchService {
public static void main(String[] args) throws Exception {
final FileSystem fileSystem = FileSystems.getDefault();
try (final WatchService watchService = fileSystem.newWatchService()) {
final Map<WatchKey, Path> keyMap = new HashMap<WatchKey, Path>();
final Path path = Paths.get("F:\\Test");
keyMap.put(path.register(watchService, ENTRY_CREATE, ENTRY_DELETE),path);
WatchKey watchKey;
do {
watchKey = watchService.take();
final Path eventDir = keyMap.get(watchKey);
for (final WatchEvent<?> event : watchKey.pollEvents()) {
final WatchEvent.Kind kind = event.kind();
final Path eventPath = (Path) event.context();
System.out.println(eventDir + ": " + event.kind() + ": " + event.context());
}
} while (watchKey.reset());
}
}
}
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jnotify
详见 http://www.blogjava.net/pengo/archive/2011/01/09/342622.html
jnotify分为64位 和 32位。 详见 http://jnotify.sourceforge.net/
public class Test {
/**
* @param args
*/
public static void main(String[] args) throws Exception{
// 监控目录
String rootDir = "Z:\\";
String path = rootDir;
int mask = JNotify.FILE_CREATED | JNotify.FILE_DELETED
| JNotify.FILE_MODIFIED | JNotify.FILE_RENAMED;
boolean watchSubtree = true;
while (true) { //否则一次就完了
System.out.println("begin watch");
JNotify.addWatch(path, mask, watchSubtree, new MyJnotifyListner());
Thread.sleep(10000);
System.out.println("end watch");
}
}
}
import net.contentobjects.jnotify.JNotifyListener;
public class MyJnotifyListner implements JNotifyListener {
public void fileRenamed(int wd, String rootPath, String oldName,
String newName) {
System.out.println("文件：" + rootPath + " : " + oldName + " 重命名为： "
+ newName + "\n");
}
public void fileModified(int wd, String rootPath, String name) {
System.out.println("文件修改 " + rootPath + " : " + name + "\n");
}
public void fileDeleted(int wd, String rootPath, String name) {
System.out.println("删除文件： " + rootPath + " : " + name + "\n");
}
public void fileCreated(int wd, String rootPath, String name) {
System.out.println("新建文件: " + rootPath + " : " + name + "\n");
}
}
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