我尝试在Java WatchService中实现简单的重命名。
我的假设是：当文件被重命名时，会执行三个操作
- 删除文件xxx
- 创建文件yyy
- 修改文件yyy
以下是我的代码：
MyWatcher.java
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.WatchKey;
import java.nio.file.WatchService;
import java.util.ArrayList;
import java.util.List;
public class MyWatcher {
@SuppressWarnings("rawtypes")
public static void main(String[] strings) {
Path myWatchPath = Paths.get("D:\\log4j");
long preventDuplicateTime = 0;
FileDelete onDelete = new FileDelete();//this object must be thread safe
List<String> notifications = new ArrayList<String>();
WatchService myPathWatchService = null;
try {
myPathWatchService = FileSystems.getDefault().newWatchService();
} catch (IOException e) {
e.printStackTrace();
}
try {
myWatchPath.register(myPathWatchService,
StandardWatchEventKinds.ENTRY_CREATE,
StandardWatchEventKinds.ENTRY_DELETE,
StandardWatchEventKinds.ENTRY_MODIFY);
} catch (IOException e) {
e.printStackTrace();
}
boolean isKeyValid = true;
while (isKeyValid) {
WatchKey myPathWatchKey = null;
try {
myPathWatchKey = myPathWatchService.take();
} catch (InterruptedException e) {
e.printStackTrace();// throw
}
for (WatchEvent watchEvent : myPathWatchKey.pollEvents()) {
//WatchEvent.Kind kind = watchEvent.kind();
if (StandardWatchEventKinds.ENTRY_CREATE.equals(watchEvent
.kind())) {
String fileName = watchEvent.context().toString();
if(onDelete.status == -1)
System.out.println("File Created:" + fileName + " "
+ watchEvent.context());
else{
if(onDelete.status == 0){
onDelete.createdTime = System.nanoTime();
if (onDelete.deletedTime / 10000000 == onDelete.createdTime / 10000000) {
onDelete.createdFile = watchEvent.context().toString();
onDelete.status++;
notifications.add("File Created:" + fileName);
}else{
for (String string : notifications) {
System.out.println(string);
}
notifications = new ArrayList<String>();
System.out.println("File Created:" + fileName + " "
+ watchEvent.context());
onDelete = new FileDelete(); //Time duration not close (seems not renamed)
}
}else{
//this should never come here!!
onDelete = new FileDelete();
}
}
}
if (StandardWatchEventKinds.ENTRY_DELETE.equals(watchEvent
.kind())) {
String fileName = watchEvent.context().toString();
if(onDelete.status == -1){
onDelete = new FileDelete();
onDelete.status++;
onDelete.deletedFile = watchEvent.context().toString();
onDelete.deletedTime = System.nanoTime();
notifications.add("File deleted:" + fileName);
}
//System.out.println("File deleted:" + fileName); // push to notfication to array for later use
}
if (StandardWatchEventKinds.ENTRY_MODIFY.equals(watchEvent
.kind())) {
long current = System.nanoTime();
String fileName = watchEvent.context().toString();
if(!(preventDuplicateTime/10000000 == current/10000000))
notifications.add("File modified:" + fileName);
preventDuplicateTime = (System.nanoTime());
onDelete.modifiedFile= fileName;
onDelete.modifiedTime =System.nanoTime();
if(onDelete.status != 1){
for (String messages : notifications) {
System.out.println(messages);
}
onDelete= new FileDelete();
notifications = new ArrayList<String>();
}
else if(onDelete.createdFile.equals(onDelete.modifiedFile))
if( onDelete.createdTime /10000000 == onDelete.modifiedTime/10000000){
System.out.println("File renamed:" + fileName);
onDelete = new FileDelete();
notifications = new ArrayList<String>();
}
}
/*}*/
}
isKeyValid = myPathWatchKey.reset();
}
}
}
FileRename.java
public class FileRename {
int status =-1;
String deletedFile = "";
long deletedTime = 0 ;
String createdFile = "";
long createdTime =0 ;
String modifiedFile = "";
long modifiedTime = 0 ;
}
它在重命名操作上完美显示，但问题是我无法弄清楚如何在删除时显示。因为每个删除都被推送到通知中！否则请帮助我实现重命名！
*注意，请不要建议使用第三方jar包！（因为大多数像JNotify这样的jar包依赖于操作系统）