/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.eclipse.dfs;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.ui.PlatformUI;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSchException;
/**
* File handling methods for the DFS
*/
public class DfsFile extends DfsPath {
public DfsFile(DfsPath parent, String path) {
super(parent, path);
}
/**
* Download and view contents of a file in the DFS NOTE: may not work on
* files >1 MB.
*
* @return a FileInputStream for the file
*/
public FileInputStream open() throws JSchException, IOException,
InvocationTargetException, InterruptedException {
File tempFile =
File.createTempFile("hadoop" + System.currentTimeMillis(), "tmp");
tempFile.deleteOnExit();
this.downloadToLocalFile(tempFile);
// file size greater than 1 MB
if (tempFile.length() > 1024 * 1024) {
boolean answer =
MessageDialog.openQuestion(null, "Show large file from DFS?",
"The file you are attempting to download from the DFS, "
+ this.getPath() + " is over 1MB in size. \n"
+ "Opening this file may cause performance problems."
+ " You can open the file with your favourite editor at "
+ tempFile.getAbsolutePath()
+ " (it's already saved there)."
+ " Continue opening the file in eclipse?");
if (!answer) {
return null;
}
}
return new FileInputStream(tempFile);
}
public void downloadToLocalFile(File localFile) throws JSchException,
IOException, InvocationTargetException, InterruptedException {
final ChannelExec exec =
exec(" dfs " + DfsFolder.s_whichFS + " -cat " + getPath());
final OutputStream os =
new BufferedOutputStream(new FileOutputStream(localFile));
try {
PlatformUI.getWorkbench().getProgressService().busyCursorWhile(
new IRunnableWithProgress() {
public void run(IProgressMonitor monitor)
throws InvocationTargetException {
try {
monitor.beginTask("View file from Distributed File System",
IProgressMonitor.UNKNOWN);
exec.connect();
BufferedInputStream stream =
new BufferedInputStream(exec.getInputStream());
byte[] buffer = new byte[1024];
int bytes;
while ((bytes = stream.read(buffer)) >= 0) {
if (monitor.isCanceled()) {
os.close();
return;
}
monitor.worked(1);
os.write(buffer, 0, bytes);
}
monitor.done();
} catch (Exception e) {
throw new InvocationTargetException(e);
}
}
});
} finally {
if (exec.isConnected()) {
exec.disconnect();
}
os.close();
}
}
/* @inheritDoc */
@Override
public void downloadToLocalDirectory(String localDirectory)
throws InvocationTargetException, JSchException, InterruptedException,
IOException {
File dir = new File(localDirectory);
if (!dir.exists() || !dir.isDirectory())
return; // TODO display error message
File dfsPath = new File(this.getPath());
File destination = new File(dir, dfsPath.getName());
if (destination.exists()) {
boolean answer =
MessageDialog.openQuestion(null, "Overwrite existing local file?",
"The file you are attempting to download from the DFS "
+ this.getPath()
+ ", already exists in your local directory as "
+ destination + ".\n" + "Overwrite the existing file?");
if (!answer)
return;
}
this.downloadToLocalFile(destination);
}
}