com.wipro.ats.bdre.tdimport.FileMonitor.java Source code

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Here is the source code for com.wipro.ats.bdre.tdimport.FileMonitor.java

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/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.wipro.ats.bdre.tdimport;

import com.wipro.ats.bdre.exception.BDREException;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.collections4.map.LinkedMap;
import org.apache.commons.vfs2.*;
import org.apache.log4j.Logger;

/**
 * Created by vishnu on 1/11/15.
 */
public class FileMonitor implements FileListener {
    private static final Logger LOGGER = Logger.getLogger(FileMonitor.class);
    private static FileMonitor fileMonitor = null;

    private String monDir = null;
    private String archiveDirName = null;
    private String filePattern = null;
    /* this data structure is used to maintain order and getting eldest element
    * Map contain Filename as key and FileCopyInfo as value    * */
    private static LinkedMap<String, FileCopyInfo> fileToCopyMap = new LinkedMap<String, FileCopyInfo>();

    private FileMonitor() {
        init();
    }

    public static synchronized FileCopyInfo getFileInfoFromQueue() {
        String key = FileMonitor.fileToCopyMap.firstKey();
        return fileToCopyMap.remove(key);
    }

    public static synchronized void addToQueue(String fileName, FileCopyInfo fileCopyInfo) {
        fileToCopyMap.put(fileName, fileCopyInfo);
    }

    public static synchronized int getQueueSize() {
        return fileToCopyMap.size();
    }

    //Singleton pattern
    public static FileMonitor getInstance() {
        if (fileMonitor == null) {
            fileMonitor = new FileMonitor();
        }
        return fileMonitor;
    }

    //Read the monitored directories, file patterns, subprocessIds and serverIds and build the HashTable
    private void init() {
        monDir = TDImportRunnableMain.getMonitoredDirName();
        filePattern = TDImportRunnableMain.getFilePattern();
        archiveDirName = TDImportRunnableMain.ARCHIVE;
    }

    //This method will get invoked when a file created in the directory.
    @Override
    public void fileCreated(FileChangeEvent fileChangeEvent) throws Exception {
        FileObject obj = fileChangeEvent.getFile();
        LOGGER.debug("File Created " + obj.getURL());
        String dirPath = obj.getParent().getName().getPath();
        LOGGER.debug("Full path " + obj.getName().getPath());

        //Don't process anything with _archive
        if (dirPath.startsWith(monDir + "/" + archiveDirName)) {
            return;
        }
        //Don't process directory
        if (obj.getType() == FileType.FOLDER) {
            return;
        }

        String fileName = obj.getName().getPath();

        //Checking if the file name matches with the given pattern
        if (fileName.matches(filePattern)) {
            FileContent fc = obj.getContent();
            LOGGER.debug("Matched File Pattern by " + fileName);
            putEligibleFileInfoInMap(obj.getName().getBaseName(), fc);
        }
    }

    private static void putEligibleFileInfoInMap(String fileName, FileContent fc) {
        // *Start*   Eligible files moved to data structure for ingestion to HDFS
        FileCopyInfo fileCopyInfo = new FileCopyInfo();
        try {
            fileCopyInfo.setFileName(fileName);
            fileCopyInfo.setSubProcessId(TDImportRunnableMain.getSubProcessId());
            fileCopyInfo.setServerId(Integer.toString(123461));
            fileCopyInfo.setSrcLocation(fc.getFile().getName().getPath());
            fileCopyInfo.setTdTable(TDImportRunnableMain.getTdTable());
            fileCopyInfo.setFileHash(DigestUtils.md5Hex(fc.getInputStream()));
            fileCopyInfo.setFileSize(fc.getSize());
            fileCopyInfo.setTimeStamp(fc.getLastModifiedTime());
            fileCopyInfo.setTdDB(TDImportRunnableMain.getTdDB());
            fileCopyInfo.setTdUserName(TDImportRunnableMain.getTdUserName());
            fileCopyInfo.setTdPassword(TDImportRunnableMain.getTdPassword());
            fileCopyInfo.setTdDelimiter(TDImportRunnableMain.getTdDelimiter());
            fileCopyInfo.setTdTpdid(TDImportRunnableMain.getTdTpdid());
            // putting element to structure
            addToQueue(fileName, fileCopyInfo);
        } catch (Exception err) {
            LOGGER.error("Error adding file to queue ", err);
            throw new BDREException(err);
        }
        // *End*   Eligible files moved to data structure for ingestion to HDFS
    }

    @Override
    public void fileDeleted(FileChangeEvent fileChangeEvent) throws Exception {
        //nothing to do
    }

    @Override
    public void fileChanged(FileChangeEvent fileChangeEvent) throws Exception {
        //nothing to do
    }

}