package org.apache.torque.util;

 import java.io.File;

 import java.util.List;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 public class ChangeDetector {

         private static final Log log = LogFactory.getLog(ChangeDetector.class);

         File controlFile;

         List<File> files;

         public ChangeDetector() {

                 this(null, null);

         }

         public ChangeDetector(File controlFile, List<File> files) {

                 super();

                 this.controlFile = controlFile;

                 this.files = files;

         }

         /**

          * Return true if any file in the list of files has a last modified timestamp newer than the control file or if the

          * control file does not exist

          */

         public boolean isChanged() {

                 if (!getControlFile().exists()) {

                         log.debug("File " + getControlFile().getAbsolutePath() + " does not exist.  Returning true");

                         return true;

                 }

                 long lastModified = getControlFile().lastModified();

                 for (File file : getFiles()) {

                         if (file.lastModified() > lastModified) {

                                 log.debug("File " + file.getAbsolutePath() + " was modified after " + getControlFile().getAbsolutePath() + " was last modified");

                                 return true;

                         }

                 }

                 log.debug("No files were modified.");

                 return false;

         }

         public File getControlFile() {

                 return controlFile;

         }

         public void setControlFile(File controlFile) {

                 this.controlFile = controlFile;

         }

         public List<File> getFiles() {

                 return files;

         }

         public void setFiles(List<File> files) {

                 this.files = files;

         }

 }