java7 NIO2 watching service API

时间:2023-03-09 03:59:19
java7 NIO2 watching service API

java7 NIO2新增了文件系统的相关事件处理API,为目录,文件新增修改删除等事件添加事件处理。

package reyo.sdk.utils.file;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchEvent.Kind;
import java.nio.file.WatchKey;
import java.nio.file.WatchService; public class NIO2WatchService { // WatchService 是线程安全的,跟踪文件事件的服务,一般是用独立线程启动跟踪
public void watchRNDir(Path path) throws IOException, InterruptedException {
try (WatchService watchService = FileSystems.getDefault().newWatchService()) {
// 给path路径加上文件观察服务
path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE);
// start an infinite loop
while (true) {
// retrieve and remove the next watch key
final WatchKey key = watchService.take();
// get list of pending events for the watch key
for (WatchEvent<?> watchEvent : key.pollEvents()) {
// get the kind of event (create, modify, delete)
final Kind<?> kind = watchEvent.kind();
// handle OVERFLOW event
if (kind == StandardWatchEventKinds.OVERFLOW) {
continue;
}
// 创建事件
if (kind == StandardWatchEventKinds.ENTRY_CREATE) { }
// 修改事件
if (kind == StandardWatchEventKinds.ENTRY_MODIFY) { }
// 删除事件
if (kind == StandardWatchEventKinds.ENTRY_DELETE) { }
// get the filename for the event
@SuppressWarnings("unchecked")
final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent;
final Path filename = watchEventPath.context();
// print it out
System.out.println(kind + " -> " + filename); }
// reset the keyf
boolean valid = key.reset();
// exit loop if the key is not valid (if the directory was
// deleted, for
if (!valid) {
break;
}
}
}
} /**
* @param args
*/
public static void main(String[] args) { // String sourceDir = "D:\\temp";
//
// Vector<String> v1 = FileOptionUtil.listAllDirAndFile(sourceDir,
// sourceDir, true);
//
// for (int i = 0; i < v1.size(); i++) {
// String fileNameb = v1.get(i);
// if (fileNameb.indexOf(".") != -1) {
// fileNameb = FileOptionUtil.getFileNameNoEx(fileNameb).substring(0,
// FileOptionUtil.getFileNameNoEx(fileNameb).length() - 14) + "." +
// FileOptionUtil.getExtensionName(fileNameb);
// } else {
// fileNameb = fileNameb.substring(0, fileNameb.length() - 14);
// }
//
// } final Path path = Paths.get("D:\\temp");
NIO2WatchService watch = new NIO2WatchService();
try {
watch.watchRNDir(path);
} catch (IOException | InterruptedException ex) {
System.err.println(ex);
} } }