Java Lightweight file Monitoring

Introduced

This article mainly introduces a kind of lightweight file monitoring method, the file Create & change & Delete, there is a corresponding event method for processing. For the core file monitor class, we inherited a listener adapter class Filealterationlisteneradaptor, which makes it easier to rewrite every event method.

File Generator Class

Package Shuai.study.file.generator;import Java.io.ioexception;import Java.nio.file.files;import Java.nio.file.paths;import Java.util.date;import Org.apache.log4j.logger;import shuai.study.file.tooler.commontooler;/** * @author Shengshu * */public class Filegenerator implements Runnable {private S Tatic final Logger LOG = Logger.getlogger (filegenerator.class);p rivate String directory = null;private static Date date = New Date ();p ublic filegenerator (String directory) {this.directory = directory;} private void Generator (string directory) {for (int i = 0; i <; i++) {String fileName = Commontooler.getdatetimeforma T (date) + "-" + Thread.CurrentThread (). GetId () + i + ". PM"; Log.info ("[Path]:" + directory + "/" + FileName); try {//Create file (path:directory/filename) files.createfile (paths.get (directory, FileName));} catch (IOException IoE) {ioe.printstacktrace ();}}} @Overridepublic void Run () {this.generator (directory);}}

File Monitor Class

Package Shuai.study.file.monitor;import Java.io.file;import Java.io.ioexception;import Org.apache.commons.io.fileutils;import Org.apache.commons.io.filenameutils;import Org.apache.commons.io.filefilter.filefilterutils;import Org.apache.commons.io.monitor.filealterationlisteneradaptor;import Org.apache.commons.io.monitor.filealterationmonitor;import Org.apache.commons.io.monitor.FileAlterationObserver Import Org.apache.log4j.logger;import shuai.study.file.tooler.commontooler;/** * @author Shengshu * */public class FileMonitor extends Filealterationlisteneradaptor {private static final Logger LOG = Logger.getlogger (filemonitor.class  );p rivate static filemonitor filemonitor;private static int pagenumber = 0;private FileMonitor () {}//Get Singleton object Instancepublic static FileMonitor Getfilemonitor () {if (FileMonitor = = null) {synchronized (Filemonitor.class) {if (Filem Onitor = = null) {FileMonitor = new FileMonitor ();}}} return filemonitor;} Create file event@overridepublic void OnFiLecreate (file file) {log.info ("[Create]:" + file.getabsolutepath ()); String Fileabsolutepath = File.getabsolutepath (); String Fileabsoluteparentpath = File.getparent (); String filebasename = Filenameutils.getbasename (Fileabsolutepath); File DestFile = new file (Fileabsoluteparentpath + file.separator + filebasename + "-" + Commontooler.pagingformat (pageNumb ER) + ". xml"), try {fileutils.movefile (file, destfile),} catch (IOException IoE) {ioe.printstacktrace ();} pagenumber++;} Change file event@overridepublic void onfilechange (file file) {log.info ("[Change]:" + file.getabsolutepath ());} Delete file event@overridepublic void onfiledelete (file file) {log.info ("[Delete]:" + file.getabsolutepath ());} public void Monitor (String directory, int. interval) {//Observer file whose suffix is pm filealterationobserver filealtera Tionobserver = new Filealterationobserver (directory, Filefilterutils.and (Filefilterutils.filefilefilter (), Filefilterutils.suffixfilefilter (". PM")), null);//ADD listener for EVent (File Create & change & Delete) Filealterationobserver.addlistener (this);//Monitor per Intervalfilealterationmonitor filealterationmonitor = new Filealterationmonitor (interval, filealterationobserver); try {//Start to Monitorfilealterationmonitor.start ();} catch (Exception e) {e.printstacktrace ()}}}

File Tester Class

Package Shuai.study.file.tester;import Java.io.ioexception;import Java.nio.file.files;import java.nio.file.Paths; Import Org.apache.log4j.logger;import Shuai.study.file.generator.filegenerator;import shuai.study.file.monitor.filemonitor;/** * @author Shengshu * */public class Filetester {private static final Logger LOG = Logger.getlogger (filetester.class);p rivate static String directory = "/home/omc/tmp";p ublic static void Main (string[]  args) {//Create directory if it does not exist try {files.createdirectory (paths.get (directory));} catch (IOException IoE) {Ioe.printstacktrace ();} Log.info ("File Monitor ...");//Start to monitor File event per millisecondsfilemonitor.getfilemonitor (). Monitor ( directory, 500); Log.info ("File generater ...");//New runnable instancefilegenerator filegeneratorrunnable = new Filegenerator ( directory)//Start to Multi-thread for generating filefor (int i = 0; i <; i++) {Thread filegeneratorthread = new T Hread (filegeneratorrunnable); filegeneratorthread. Start ();}}} 

Common Tool Class

Package Shuai.study.file.tooler;import java.text.simpledateformat;import java.util.date;/** * @author Shengshu *  */public class Commontooler {//Date time formatpublic static String Getdatetimeformat (date date) {SimpleDateFormat simple DateFormat = new SimpleDateFormat ("yyyymmdd-hhmm"); String datetime = Simpledateformat.format (date); return datetime;} Page formatpublic static string pagingformat (int pagenumber) {String pagenumberstr = "P00"; if (PageNumber < 0) {thro W New NumberFormatException ("the page number should not be negative");} if (PageNumber <) {Pagenumberstr = String.Format ("p0%d", pagenumber);} else {pagenumberstr = String.Format ("P%d", PA Genumber);} return pagenumberstr;}}

Java Lightweight file monitoring