File Retention or Cleanup in java

How to cleanup files from file store based on retention period

Sample Java Program:

public class McatSRSFileUtil {

     
     private static Logger logger = LoggerFactory.getLogger(McatSRSFileUtil.class); 
   
     private Date currDate = new Date(); 
     private String pathToBeExcluded = ""; 
     
     /**
      * Main method would be invioked by quartz job to clean up the file which is older than 90 days
      * 
      * @throws Exception
      */ 
    public void processFileRetention(String srcDir, int retentionPeriod)
            throws Exception {
        logger.info("HOUSE KEEPING PROCESS - START");

        executeFileRetention(new File(srcDir), retentionPeriod);

        logger.info("HOUSE KEEPING PROCESS - COMPLETED");
    }
     
     /**
      * DELETE FILES OLDER THAN SPECIFED RETENTION PERIOD
      * 
      * @param deleteDir
      * @param retentionPeriod
      * @throws IOException
      */ 
    private void executeFileRetention(File deleteDir, int retentionPeriod)
            throws IOException {
        if (!deleteDir.exists()) {
            logger.warn("SKIP RETENTION... INVALID DIRECTORY TO DELETE FILE FROM -"
                    + deleteDir);
            return;
        }

        if (retentionPeriod == 0) {
            logger.warn("SKIP RETENTION... RETENTION PERIOD NOT SPECIFIED");
            return;
        }

        logger.info("CHECKING FOR OLD FILES IN DIR - "
                + deleteDir.getCanonicalPath());

        File[] dirList = deleteDir.listFiles();
        if (dirList.length == 0) {
            logger.info("NO FILES FOUND IN " + deleteDir.getCanonicalPath());
            return;
        }
        for (File file : dirList) {
            logger.trace("processing file:" + file);
            if (file.isDirectory()) {
                // DO NOT DELETE DIRECTORIES!!!!
                // RECURSIVELY CHECK SUB-DIRECTORIES FOR OLDER FILES
                executeFileRetention(file, retentionPeriod);
            } else if (file.isFile()) {
                // TODO CHEK FOR FILENAME PATTERN
                if (isFileOld(file, retentionPeriod)) {
                    deleteFile(file);
                }
            }
        }

    }
     
     /**
      * 
      * @param file
      *            file to be verified
      * @param retentionPeriod
      *            number of days to retain files
      * @return
      * @throws IOException
      */ 
     private boolean isFileOld(File file, int retentionPeriod) 
       throws IOException { 
      Date lastModifiedDate; 
      lastModifiedDate = new Date(file.lastModified()); 
      logger.trace(file + " last modified on " + lastModifiedDate); 
      int diffInDays = getDifferenceInDays(currDate, lastModifiedDate); 
      logger.trace("DIFF IN DAYS:" + diffInDays); 
     
      if (diffInDays > retentionPeriod) { 
       logger.trace(file.getCanonicalPath() + " IS OLD. DAYS-" 
         + diffInDays); 
       return true; 
      } 
      return false; 
     } 
      
     
     /**
      * DELETE SPECIFIED FILE
      * 
      * @param file
      *            file to be deleted
      * @throws IOException
      */ 
     public void deleteFile(File file) throws IOException { 
      String strCanonicalPath = file.getCanonicalPath(); 
      logger.debug("DELETING FILE " + strCanonicalPath); 
      // DO NOT DELETE ANY DIRECTORIES 
      if (!file.exists() || !file.isFile()) { 
       logger.error("INVALID FILE " + strCanonicalPath); 
       return; 
      } 
      boolean deleteStatus = file.delete(); 
      if (!deleteStatus) { 
       logger.error("FAILED TO DELETE FILE " + strCanonicalPath); 
      } 
     } 
     
     /**
      * derive file name to be used in tar. basically removes the directory path.
      * 
      * @param file
      * @return file name to be used in tar
      * @throws IOException
      */ 
     private String getFileName(File file) throws IOException { 
      // filename to be used in tar 
      String strCanonicalPath = file.getCanonicalPath(); 
      String fileName = ""; 
      // INDEX OF SRC 
      int index = strCanonicalPath.indexOf(pathToBeExcluded); 
      if (index >= 0) { 
       fileName = strCanonicalPath.substring(index 
         + pathToBeExcluded.length() + 1); 
      } 
      logger.trace("Name to be used in TAR-" + fileName); 
      return fileName; 
     } 
     
     // ************ COMMON UTILITY FUNCTIONS **************** 
     
     /**
      * CLOSE STREAM
      * 
      * @param stream
      * @throws IOException
      */ 
     private void close(Closeable stream) throws IOException { 
      try { 
       if (stream != null) { 
        stream.close(); 
       } 
      } catch (IOException ioEx) { 
       logger.warn("error closing stream", ioEx); 
       throw ioEx; 
      } 
     } 
   
     /**
      * This method checks whether the string is empty or not
      * 
      * @param strToCheck
      *            the string to be checked
      * @return it returns true if the string is null or empty, otherwise it
      *         returns false
      */ 
     public static boolean isStringEmpty(String strToCheck) { 
      if ((null == strToCheck) || strToCheck.trim().isEmpty()) { 
       return true; 
      } else { 
       return false; 
      } 
     } 
     
     /**
      * get the difference in days between two dates. considers DST.
      * 
      * @param date1
      *            the first date
      * @param date1
      *            the second date
      * 
      * @return int the difference in days (-ve if date1 < date2)
      * @throws ParseException
      */ 
     public static int getDifferenceInDays(Date date1, Date date2) { 
     
      Calendar cal1 = Calendar.getInstance(); 
      cal1.setTime(date1); 
     
      Calendar cal2 = Calendar.getInstance(); 
      cal2.setTime(date2); 
     
      // HAVE TO CONVERT BOTH THE INPUT DATES TO GMT TIMEZONE 
     
      // cal.getTimeZone().getOffset(cal.getTimeInMillis()) -> amount of time 
      // in milliseconds to add to GMT to get local time 
     
      long timeDiff = (cal1.getTimeInMillis() + cal1.getTimeZone().getOffset( 
        cal1.getTimeInMillis())) 
        - (cal2.getTimeInMillis() + cal2.getTimeZone().getOffset( 
          cal2.getTimeInMillis())); 
      return (int) TimeUnit.MILLISECONDS.toDays(timeDiff); 
     
      // long timeDiff = Math.abs(date1.getTime() - date2.getTime()); 
      // return (int) TimeUnit.MILLISECONDS.toDays(timeDiff); 
     } 
     
     /**
      * get current date
      * 
      * @param dateFormat
      * @return
      */ 
     public static String getCurrentDateTime(String dateFormat) { 
      Date today = new Date(); 
      DateFormat formatter = new SimpleDateFormat(dateFormat); 
      return formatter.format(today); 
     } 
     
    public static void main(String[] args) {
        String srcDir = "C:\\opt\\filestore\\appdata\\ci\\import";
        McatSRSFileUtil tester = new McatSRSFileUtil();
        try {
            tester.processFileRetention(srcDir, 60);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
   
}

Findout the File Extension in java

How to findout the file extension in java



    public String getFileExtension(File file) {
        String fileName = file.getAbsolutePath()+ file.getName();
       
        String extn = FilenameUtils.getExtension(fileName);
        return extn;
    }

Writing A text/xml file into a Tomcat WEB-INF folder

How to write a file(text or xml) file into a TOMCAT WEB-INF folder


code snippet  for writing a text file into the Tomcat WEB-INF folder:

...
...

String realPath = getServletContext().getRealPath("/WEB-INF/log");

// it returns  D:\apps\apache-tomcat-6.0.24\webapps\CodeAnalyser\WEB-INF\log  as realPath value

File curFile = File.createTempFile("SopOut", ".txt", new File(realPath));

// it will creat a file SopOUt.txt in to the  D:\apps\apache-tomcat-6.0.24\webapps\CodeAnalyser\WEB-INF\log  folder

// write to file

FileWriter fw = new FileWriter(curFile);

try {

      fw.write(sb); // sb contains the content to be written into the file

} finally {

    fw.flush();

    fw.close();

}

...
...