import java.io.File;
import java.io.FileFilter;public class FileFilterImpl implements FileFilter { public boolean accept(File pathname) {
System.out.println("file_filter: "+pathname);
return false;
}
}适配器代码
import java.io.File;import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;
import org.apache.commons.io.monitor.FileAlterationObserver;public class FileListenerAdaptor extends FileAlterationListenerAdaptor { @Override
public void onStart(FileAlterationObserver arg0) {
System.out.println("begin listening!");
super.onStart(arg0);
} @Override
public void onStop(FileAlterationObserver arg0) {
System.out.println("end listening!");
super.onStop(arg0);
} @Override
public void onDirectoryCreate(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is created.");
super.onDirectoryCreate(fold);
} @Override
public void onDirectoryChange(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is changed.");
super.onDirectoryChange(fold);
} @Override
public void onDirectoryDelete(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is deleted.");
super.onDirectoryDelete(fold);
} @Override
public void onFileCreate(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is created.");
super.onFileCreate(file);
} @Override
public void onFileChange(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is changed.");
super.onFileChange(file);
} @Override
public void onFileDelete(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is deleted");
super.onFileDelete(file);
}}import java.io.File;import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;public class FileListenerTest { public static void main(String[] args) {
try {
// 构造观察类主要提供要观察的文件或目录,当然还有详细信息的filter
FileAlterationObserver observer = new FileAlterationObserver(
new File("e:\\test1"), new FileFilterImpl(),null);
// 构造收听类
FileListenerAdaptor listener = new FileListenerAdaptor();
// 为观察对象添加收听对象
observer.addListener(listener);
// 配置Monitor,第一个参数单位是毫秒,是监听的间隔;第二个参数就是绑定我们之前的观察对象。
FileAlterationMonitor fileMonitor = new FileAlterationMonitor(
5000, new FileAlterationObserver[] { observer });
// 启动开始监听
fileMonitor.start();
} catch (Exception e) {
System.out.println("监听启动失败!");
e.printStackTrace();
}
}
}目录 e:\\test1 下只有一个文件,但首次启动时会扫描两次该目录,然后才会正常5秒扫描一次,怎么才能首次启动只调用一次public boolean accept(File pathname); 方法呢。javafilefilter
import java.io.FileFilter;public class FileFilterImpl implements FileFilter { public boolean accept(File pathname) {
System.out.println("file_filter: "+pathname);
return false;
}
}适配器代码
import java.io.File;import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;
import org.apache.commons.io.monitor.FileAlterationObserver;public class FileListenerAdaptor extends FileAlterationListenerAdaptor { @Override
public void onStart(FileAlterationObserver arg0) {
System.out.println("begin listening!");
super.onStart(arg0);
} @Override
public void onStop(FileAlterationObserver arg0) {
System.out.println("end listening!");
super.onStop(arg0);
} @Override
public void onDirectoryCreate(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is created.");
super.onDirectoryCreate(fold);
} @Override
public void onDirectoryChange(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is changed.");
super.onDirectoryChange(fold);
} @Override
public void onDirectoryDelete(File fold) {
System.out.println("fold: " + fold.getAbsolutePath() + " is deleted.");
super.onDirectoryDelete(fold);
} @Override
public void onFileCreate(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is created.");
super.onFileCreate(file);
} @Override
public void onFileChange(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is changed.");
super.onFileChange(file);
} @Override
public void onFileDelete(File file) {
System.out.println("file: " + file.getAbsolutePath() + " is deleted");
super.onFileDelete(file);
}}import java.io.File;import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;public class FileListenerTest { public static void main(String[] args) {
try {
// 构造观察类主要提供要观察的文件或目录,当然还有详细信息的filter
FileAlterationObserver observer = new FileAlterationObserver(
new File("e:\\test1"), new FileFilterImpl(),null);
// 构造收听类
FileListenerAdaptor listener = new FileListenerAdaptor();
// 为观察对象添加收听对象
observer.addListener(listener);
// 配置Monitor,第一个参数单位是毫秒,是监听的间隔;第二个参数就是绑定我们之前的观察对象。
FileAlterationMonitor fileMonitor = new FileAlterationMonitor(
5000, new FileAlterationObserver[] { observer });
// 启动开始监听
fileMonitor.start();
} catch (Exception e) {
System.out.println("监听启动失败!");
e.printStackTrace();
}
}
}目录 e:\\test1 下只有一个文件,但首次启动时会扫描两次该目录,然后才会正常5秒扫描一次,怎么才能首次启动只调用一次public boolean accept(File pathname); 方法呢。javafilefilter
file_filter: e:\test1\abc.txt
begin listening!
file_filter: e:\test1\abc.txt
end listening!回调了onStart和onStop,一个完整的监听过程,不算两次吧
不太明白啊,为什么监听起动之后,会打印一次 file_filter: e:\test1\abc.txt
首启动就要打印两次 file_filter: e:\test1\abc.txt
import java.io.FileFilter;public class FileFilterImpl implements FileFilter { public boolean accept(File pathname) {
System.out.println("file_filter: "+pathname);
return false;
}
}
我现在想实现处理所扫描到文件的一些方法,但首启动会调用2次这个方法,应该怎么做啊。
楼主着重考虑FileListenerAdaptor 里面的代码,就好了。过滤器FileFilter设计的目的,只是过滤掉不需要进行监听的文件。
也就是说FileFilterImpl 里面,只决定什么样的文件能进行监听,什么样的文件不监听。
至于,监听到的文件进行什么样的处理,在FileListenerAdaptor 里进行处理。