azkaban.viewer.hdfs.HdfsImageFileViewer.java Source code

Introduction

Here is the source code for azkaban.viewer.hdfs.HdfsImageFileViewer.java

Source

/*
 * Copyright 2012 LinkedIn Corp.
 * 
 * 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 azkaban.viewer.hdfs;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.HashSet;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.log4j.Logger;

/**
 * Reads a image file if the file size is not larger than {@value #MAX_IMAGE_FILE_SIZE}.
 * 
 * @author ximeng
 *
 */

public class HdfsImageFileViewer implements HdfsFileViewer {

    private static Logger logger = Logger.getLogger(HdfsImageFileViewer.class);
    private static final long MAX_IMAGE_FILE_SIZE = 10485760L;

    private HashSet<String> acceptedSuffix;

    public HdfsImageFileViewer() {
        final String[] imageSuffix = { ".jpg", ".jpeg", ".tif", ".tiff", ".png", ".gif", ".bmp", ".svg" };
        acceptedSuffix = new HashSet<String>(Arrays.asList(imageSuffix));
    }

    public boolean canReadFile(FileSystem fs, Path path) {
        String fileName = path.getName();
        int pos = fileName.lastIndexOf('.');
        if (pos >= 0) {
            String suffix = fileName.substring(pos).toLowerCase();
            if (acceptedSuffix.contains(suffix)) {
                long len = 0;
                try {
                    len = fs.getFileStatus(path).getLen();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    return false;
                }
                if (len <= MAX_IMAGE_FILE_SIZE) {
                    return true;
                }
            }
        }
        return false;
    }

    public void displayFile(FileSystem fs, Path path, OutputStream outputStream, int startLine, int endLine)
            throws IOException {

        if (logger.isDebugEnabled()) {
            logger.debug("read in image file");
        }

        InputStream inputStream = null;
        try {
            inputStream = new BufferedInputStream(fs.open(path));
            BufferedOutputStream output = new BufferedOutputStream(outputStream);
            long outputSize = 0L;
            byte[] buffer = new byte[16384];
            int len;
            while ((len = inputStream.read(buffer)) != -1) {
                output.write(buffer, 0, len);
                outputSize += len;
                if (outputSize > MAX_IMAGE_FILE_SIZE)
                    break;
            }
            output.flush();
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }
        }
    }
}