Java tutorial
/** * 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.actions; import java.io.File; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; import org.apache.hadoop.eclipse.ImageLibrary; import org.apache.hadoop.eclipse.dfs.DFSActions; import org.apache.hadoop.eclipse.dfs.DFSFile; import org.apache.hadoop.eclipse.dfs.DFSFolder; import org.apache.hadoop.eclipse.dfs.DFSLocation; import org.apache.hadoop.eclipse.dfs.DFSLocationsRoot; import org.apache.hadoop.eclipse.dfs.DFSPath; import org.eclipse.core.resources.IStorage; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.core.runtime.PlatformObject; import org.eclipse.jface.action.IAction; import org.eclipse.jface.dialogs.InputDialog; import org.eclipse.jface.dialogs.MessageDialog; import org.eclipse.jface.operation.IRunnableWithProgress; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.DirectoryDialog; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.FileDialog; import org.eclipse.ui.IObjectActionDelegate; import org.eclipse.ui.IPersistableElement; import org.eclipse.ui.IStorageEditorInput; import org.eclipse.ui.IWorkbenchPart; import org.eclipse.ui.PartInitException; import org.eclipse.ui.PlatformUI; /** * Actual implementation of DFS actions */ public class DFSActionImpl implements IObjectActionDelegate { private ISelection selection; private IWorkbenchPart targetPart; /* @inheritDoc */ public void setActivePart(IAction action, IWorkbenchPart targetPart) { this.targetPart = targetPart; } /* @inheritDoc */ public void run(IAction action) { // Ignore non structured selections if (!(this.selection instanceof IStructuredSelection)) return; // operate on the DFS asynchronously to prevent blocking the main UI final IStructuredSelection ss = (IStructuredSelection) selection; final String actionId = action.getActionDefinitionId(); Display.getDefault().asyncExec(new Runnable() { public void run() { try { switch (DFSActions.getById(actionId)) { case DELETE: { delete(ss); break; } case OPEN: { open(ss); break; } case MKDIR: { mkdir(ss); break; } case UPLOAD_FILES: { uploadFilesToDFS(ss); break; } case UPLOAD_DIR: { uploadDirectoryToDFS(ss); break; } case REFRESH: { refresh(ss); break; } case DOWNLOAD: { downloadFromDFS(ss); break; } case RECONNECT: { reconnect(ss); break; } case DISCONNECT: { disconnect(ss); break; } default: { System.err.printf("Unhandled DFS Action: " + actionId); break; } } } catch (Exception e) { e.printStackTrace(); MessageDialog.openError(Display.getDefault().getActiveShell(), "DFS Action error", "An error occurred while performing DFS operation: " + e.getMessage()); } } }); } /** * Create a new sub-folder into an existing directory * * @param selection */ private void mkdir(IStructuredSelection selection) { List<DFSFolder> folders = filterSelection(DFSFolder.class, selection); if (folders.size() >= 1) { DFSFolder folder = folders.get(0); InputDialog dialog = new InputDialog(Display.getCurrent().getActiveShell(), "Create subfolder", "Enter the name of the subfolder", "", null); if (dialog.open() == InputDialog.OK) folder.mkdir(dialog.getValue()); } } /** * Implement the import action (upload files from the current machine to * HDFS) * * @param object * @throws SftpException * @throws JSchException * @throws InvocationTargetException * @throws InterruptedException */ private void uploadFilesToDFS(IStructuredSelection selection) throws InvocationTargetException, InterruptedException { // Ask the user which files to upload FileDialog dialog = new FileDialog(Display.getCurrent().getActiveShell(), SWT.OPEN | SWT.MULTI); dialog.setText("Select the local files to upload"); dialog.open(); List<File> files = new ArrayList<File>(); for (String fname : dialog.getFileNames()) files.add(new File(dialog.getFilterPath() + File.separator + fname)); // TODO enable upload command only when selection is exactly one folder List<DFSFolder> folders = filterSelection(DFSFolder.class, selection); if (folders.size() >= 1) uploadToDFS(folders.get(0), files); } /** * Implement the import action (upload directory from the current machine * to HDFS) * * @param object * @throws SftpException * @throws JSchException * @throws InvocationTargetException * @throws InterruptedException */ private void uploadDirectoryToDFS(IStructuredSelection selection) throws InvocationTargetException, InterruptedException { // Ask the user which local directory to upload DirectoryDialog dialog = new DirectoryDialog(Display.getCurrent().getActiveShell(), SWT.OPEN | SWT.MULTI); dialog.setText("Select the local file or directory to upload"); String dirName = dialog.open(); final File dir = new File(dirName); List<File> files = new ArrayList<File>(); files.add(dir); // TODO enable upload command only when selection is exactly one folder final List<DFSFolder> folders = filterSelection(DFSFolder.class, selection); if (folders.size() >= 1) uploadToDFS(folders.get(0), files); } private void uploadToDFS(final DFSFolder folder, final List<File> files) throws InvocationTargetException, InterruptedException { PlatformUI.getWorkbench().getProgressService().busyCursorWhile(new IRunnableWithProgress() { public void run(IProgressMonitor monitor) throws InvocationTargetException { int work = 0; for (File file : files) work += computeUploadWork(file); monitor.beginTask("Uploading files to distributed file system", work); for (File file : files) { try { folder.upload(monitor, file); } catch (IOException ioe) { ioe.printStackTrace(); MessageDialog.openError(null, "Upload files to distributed file system", "Upload failed.\n" + ioe); } } monitor.done(); // Update the UI folder.doRefresh(); } }); } private void reconnect(IStructuredSelection selection) { for (DFSLocation location : filterSelection(DFSLocation.class, selection)) location.reconnect(); } private void disconnect(IStructuredSelection selection) { if (selection.size() != 1) return; Object first = selection.getFirstElement(); if (!(first instanceof DFSLocationsRoot)) return; DFSLocationsRoot root = (DFSLocationsRoot) first; root.disconnect(); root.refresh(); } /** * Implements the Download action from HDFS to the current machine * * @param object * @throws SftpException * @throws JSchException * @throws InterruptedException * @throws InvocationTargetException */ private void downloadFromDFS(IStructuredSelection selection) throws InvocationTargetException, InterruptedException { // Ask the user where to put the downloaded files DirectoryDialog dialog = new DirectoryDialog(Display.getCurrent().getActiveShell()); dialog.setText("Copy to local directory"); dialog.setMessage("Copy the selected files and directories from the " + "distributed filesystem to a local directory"); String directory = dialog.open(); if (directory == null) return; final File dir = new File(directory); if (!dir.exists()) dir.mkdirs(); if (!dir.isDirectory()) { MessageDialog.openError(null, "Download to local file system", "Invalid directory location: \"" + dir + "\""); return; } final List<DFSPath> paths = filterSelection(DFSPath.class, selection); PlatformUI.getWorkbench().getProgressService().busyCursorWhile(new IRunnableWithProgress() { public void run(IProgressMonitor monitor) throws InvocationTargetException { int work = 0; for (DFSPath path : paths) work += path.computeDownloadWork(); monitor.beginTask("Downloading files to local file system", work); for (DFSPath path : paths) { if (monitor.isCanceled()) return; try { path.downloadToLocalDirectory(monitor, dir); } catch (Exception e) { // nothing we want to do here e.printStackTrace(); } } monitor.done(); } }); } /** * Open the selected DfsPath in the editor window * * @param selection * @throws JSchException * @throws IOException * @throws PartInitException * @throws InvocationTargetException * @throws InterruptedException */ private void open(IStructuredSelection selection) throws IOException, PartInitException, InvocationTargetException, InterruptedException { for (DFSFile file : filterSelection(DFSFile.class, selection)) { IStorageEditorInput editorInput = new DFSFileEditorInput(file); targetPart.getSite().getWorkbenchWindow().getActivePage().openEditor(editorInput, "org.eclipse.ui.DefaultTextEditor"); } } /** * @param selection * @throws JSchException */ private void refresh(IStructuredSelection selection) { for (DFSPath path : filterSelection(DFSPath.class, selection)) path.refresh(); } private void delete(IStructuredSelection selection) { List<DFSPath> list = filterSelection(DFSPath.class, selection); if (list.isEmpty()) return; StringBuffer msg = new StringBuffer(); msg.append("Are you sure you want to delete " + "the following files from the distributed file system?\n"); for (DFSPath path : list) msg.append(path.getPath()).append("\n"); if (MessageDialog.openConfirm(null, "Confirm Delete from DFS", msg.toString())) { Set<DFSPath> toRefresh = new HashSet<DFSPath>(); for (DFSPath path : list) { path.delete(); toRefresh.add(path.getParent()); } for (DFSPath path : toRefresh) { path.refresh(); } } } /* @inheritDoc */ public void selectionChanged(IAction action, ISelection selection) { this.selection = selection; } /** * Extract the list of <T> from the structured selection * * @param clazz the class T * @param selection the structured selection * @return the list of <T> it contains */ private static <T> List<T> filterSelection(Class<T> clazz, IStructuredSelection selection) { List<T> list = new ArrayList<T>(); for (Object obj : selection.toList()) { if (clazz.isAssignableFrom(obj.getClass())) { list.add((T) obj); } } return list; } private static int computeUploadWork(File file) { if (file.isDirectory()) { int contentWork = 1; for (File child : file.listFiles()) contentWork += computeUploadWork(child); return contentWork; } else if (file.isFile()) { return 1 + (int) (file.length() / 1024); } else { return 0; } } } /** * Adapter to allow the viewing of a DfsFile in the Editor window */ class DFSFileEditorInput extends PlatformObject implements IStorageEditorInput { private DFSFile file; /** * Constructor * * @param file */ DFSFileEditorInput(DFSFile file) { this.file = file; } /* @inheritDoc */ public String getToolTipText() { return file.toDetailedString(); } /* @inheritDoc */ public IPersistableElement getPersistable() { return null; } /* @inheritDoc */ public String getName() { return file.toString(); } /* @inheritDoc */ public ImageDescriptor getImageDescriptor() { return ImageLibrary.get("dfs.file.editor"); } /* @inheritDoc */ public boolean exists() { return true; } /* @inheritDoc */ public IStorage getStorage() throws CoreException { return file.getIStorage(); } };