Problem with file searching

Question

I m trying to create a website using jsp . In that course i hav to search files (in the same or other directory) . how to do that.
plz help

Answer 1

Check out my Find.java class. It might be close to what you want
You are welcome to use and modify this class, but please don't change the package or take credit for it as your own work.
Find.java
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* Created on Jul 8, 2005 by @author Tom Jacobs
package tjacobs.io;
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Observable;
import java.util.Observer;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
//import tjacobs.util.Observable;
* Find is pretty groovy. The point of it is to find files ala windows search.
* doesn't have the advanced search options tho.
* Extends Observable so all you need to do is add an observer to it.
public class Find extends Observable implements Runnable {
     private Thread mMyThread;
     private Pattern mPattern;
     private String mDirContains;
     private File mStartDir;
     private boolean mDescOnly = false;
     private List<File> mMatches = new ArrayList<File>();
     private List<File> mDirectoriesToSearch = new ArrayList<File>();
     private Set<String> mDirectoriesSearched = new TreeSet<String>();
     private boolean mStop;
     private boolean mPause;
     public static final boolean DEBUG = false;
     private Find(Pattern pattern, File dir, boolean desc) {
          super();
          mPattern = pattern;
          mStartDir = dir;
          mDescOnly = desc;
     public int size() {
          return mMatches.size();
     public File get(int i) {
          return mMatches.get(i);
     public Iterator<File> iterator() {
          return Collections.unmodifiableList(mMatches).iterator();
     public static Find fsFind(Pattern pattern, File startDir) {
          return fsFind(pattern, startDir, false);
     public static Find fsFind(String pattern, File startDir, boolean descendOnly) {
          return fsFind(Pattern.compile(pattern), startDir, descendOnly);
     public static Find fsFind(Pattern pattern, File startDir, boolean descendOnly) {
          Find find = new Find(pattern, startDir, descendOnly);
          Thread t = new Thread(find, "Find");
          t.setDaemon(true);
          t.start();
          return find;
     public static Find fsFind(String pattern, File startDir) {
          return fsFind(Pattern.compile(pattern), startDir);
     public static Find fsFind(Pattern pattern, String startDir) {
          return fsFind(pattern, new File(startDir));
     public static Find fsFind(String pattern, String startDir) {
          return fsFind(Pattern.compile(pattern), startDir);
     public static Find fsFind(String pattern, String startDir, boolean descendOnly) {
          return fsFind(Pattern.compile(pattern), startDir, descendOnly);
     public static Find fsFind(Pattern pattern, String startDir, boolean descendOnly) {
          return fsFind(pattern, new File(startDir), descendOnly);
     public static Find fsFind(String pattern) {
          return fsFind(Pattern.compile(pattern));
     public static Find fsFind(Pattern pattern) {
          return fsFind(pattern, (File)null);
     public void join() {
          try {
               while (mMyThread == null) {
                    Thread.yield();
               mMyThread.join();
          catch (InterruptedException ex) {
               //TODO: Log this
     public synchronized void addObserver(Observer o) {
          if (o == null) return;
          int size = size();
          for (int i = 0; i < size; i++) {
               o.update(this, get(i));
          super.addObserver(o);
//          super.addObserver(o);
//          if (mMatches != null && mMatches.size() > 0) {
//               for (int i = 0; i < mMatches.size(); i++) {o.update(this, mMatches.)
     public void run() {
          mStop = false;
          mMyThread = Thread.currentThread();
          if (mStartDir == null) {
               mStartDir = new File(".");
          mStartDir = mStartDir.getAbsoluteFile();
          if (mStartDir.isDirectory()) {
               mDirectoriesToSearch.add(mStartDir);
          else {
               mDirectoriesToSearch.add(mStartDir.getParentFile());
          while (mDirectoriesToSearch.size() > 0 && !mStop) {
               if (mPause) {
                    synchronized(this) {
                         try {
                              wait();
                         catch (Exception ex) {ex.printStackTrace();}
               File toSearch = mDirectoriesToSearch.remove(0);
               //mDirectoriesSearched.add(toSearch.getAbsolutePath());
               search(toSearch);
     private void addToMatches(File dir) {
          mMatches.add(dir);
          notifyObservers(dir);
     private void search(File dir) {
          if (DEBUG) System.out.println("dir = " + dir);
          if (mDirectoriesSearched.contains(dir.getAbsolutePath())) {
               return;
          mDirectoriesSearched.add(dir.getAbsolutePath());
          if (!mDescOnly) {
               File par = dir.getParentFile();
               if (par != null) mDirectoriesToSearch.add(par);
          Matcher matcher = mPattern.matcher(dir.getName());
          if (matcher.matches()) {
               addToMatches(dir);
          boolean shouldMatch = true;
          if (mDirContains != null) {
               shouldMatch = dir.getAbsolutePath().toLowerCase().contains(mDirContains);
          File files[] = dir.listFiles();
          if (files == null) {
               return;
          for (int i =0; i < files.length; i++) {
               if (files.isDirectory()) {
                    if (DEBUG) {
                         System.out.println("adding to search: " + files[i]);
                    mDirectoriesToSearch.add(files[i]);
               else if (shouldMatch) {
                    matcher = mPattern.matcher(files[i].getName());
                    if (DEBUG) {
                         System.out.println ("Testing: " + files[i].getName());
                    //String name = files[i].getName();
                    if (matcher.matches()) {
                         super.setChanged();
                         addToMatches(files[i]);
     public void setDirContains(String str) {
          mDirContains = str.toLowerCase();
     public String getDirContains() {
          return mDirContains;
     public void pause() {
          mPause = !mPause;
          if (!mPause) {
               synchronized(this) {
                    notify();
     public void stop() {
          mStop = true;