Java tutorial
/******************************************************************************* * Copyright (c) 2013 GoPivotal, Inc. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-v10.html * * Contributors: * GoPivotal, Inc. - initial API and implementation *******************************************************************************/ package org.springframework.ide.eclipse.boot.wizard.content; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.zip.ZipException; import org.apache.commons.compress.archivers.zip.ZipArchiveEntry; import org.apache.commons.compress.archivers.zip.ZipFile; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.IPath; import org.eclipse.core.runtime.Path; import org.springframework.ide.eclipse.boot.wizard.BootWizardActivator; import org.springsource.ide.eclipse.commons.frameworks.core.downloadmanager.DownloadableItem; import org.springsource.ide.eclipse.commons.frameworks.core.downloadmanager.UIThreadDownloadDisallowed; /** * A CodeSet stored in a Downloadable Zip File. The interesting data in the * code set may be somewhere inside the zip file and is pointed to by * a path relative to the zipfile root. */ public class ZipFileCodeSet extends CodeSet { private static final boolean DEBUG = false; //(""+Platform.getLocation()).contains("kdvolder"); private void debug(String msg) { if (DEBUG) { System.out.println(msg); } } private final DownloadableItem zipDownload; private final IPath root; private Map<String, CodeSetEntry> entries = null; /** * Ensures that zip file is downloaded and entries are parsed * into a map. Only the first time this method is called do * we do any actual work. The zip entries are cached * after that. */ private synchronized void ensureEntryCache() throws Exception, UIThreadDownloadDisallowed { //Careful... if called in UIThred this may throw an exception because downloading content // in the UI thread is not allowed. Callers generally know how to deal with that but // we should take care not to accidentally leave an empty hashmap around as well. // I.e. take care not to install the map unless reading download etc of the // zip succeeded. if (entries == null) { debug(">>> caching codeset entries " + this); final HashMap<String, CodeSetEntry> newEntries = new HashMap<String, CodeSetEntry>(1024); each(new Processor<Void>() { @Override public Void doit(CodeSetEntry e) throws Exception { debug(e.getPath().toString()); newEntries.put(e.getPath().toString(), e); return null; } }); //Nothing bad happened. The cache map is ready now. this.entries = newEntries; debug("<<< cached codeset entries " + entries.size()); } } ZipFileCodeSet(String name, DownloadableItem zip, IPath root) { super(name); this.zipDownload = zip; this.root = root.makeRelative(); } @Override public String toString() { return "ZipCodeSet(" + name + ", " + zipDownload.getURL() + "@" + root + ")"; } @Override public boolean exists() throws Exception { ensureEntryCache(); return !entries.isEmpty(); } @Override public boolean hasFile(IPath path) throws UIThreadDownloadDisallowed { try { ensureEntryCache(); return entries.containsKey(fileKey(path)); } catch (UIThreadDownloadDisallowed e) { throw e; } catch (Exception e) { BootWizardActivator.log(e); } return false; } @Override public boolean hasFolder(IPath path) { try { ensureEntryCache(); return entries.containsKey(folderKey(path)); } catch (Exception e) { BootWizardActivator.log(e); } return false; } private String folderKey(IPath _path) { String path = fileKey(_path); if (!path.endsWith("/")) { //ZipEntries for dirs always end with a "/" path = path + "/"; } return path; } private String fileKey(IPath path) { path = path.makeRelative(); return path.toString(); } @Override public <T> T each(Processor<T> processor) throws Exception { T result = null; ZipFile zip = new ZipFile(zipDownload.getFile()); try { Enumeration<ZipArchiveEntry> iter = zip.getEntries(); while (iter.hasMoreElements() && result == null) { ZipArchiveEntry el = iter.nextElement(); Path zipPath = new Path(el.getName()); if (root.isPrefixOf(zipPath)) { String key = zipPath.removeFirstSegments(root.segmentCount()).toString(); if ("".equals(key)) { //path maches exactly, this means we hit the root of the // code set. Do not store it because the root of a codeset // is not actually an element of the codeset! } else { CodeSetEntry cse = csEntry(zip, el); result = processor.doit(cse); if (result != null) { //Bail out early when result found return result; } } } } return result; } finally { try { zip.close(); } catch (IOException e) { } } } @Override public <T> T readFileEntry(String path, Processor<T> processor) throws Exception { ZipFile zip = new ZipFile(zipDownload.getFile()); try { String entryName = root.append(path).toString(); ZipArchiveEntry entry = zip.getEntry(entryName); return processor.doit(entry == null ? null : csEntry(zip, entry)); } finally { try { zip.close(); } catch (IOException e) { } } } @Override protected void assertCorrectOutputLocation(java.nio.file.Path normalizedLocation, java.nio.file.Path normalizedTarget) throws Exception { if (!normalizedTarget.startsWith(normalizedLocation)) { throw new ZipException("The file " + normalizedTarget + " is trying to leave the target output directory of " + normalizedLocation); } } /** * Create a CodeSetEntry that wraps a ZipEntry */ private CodeSetEntry csEntry(final ZipFile zip, final ZipArchiveEntry e) { IPath zipPath = new Path(e.getName()); //path relative to zip file Assert.isTrue(root.isPrefixOf(zipPath)); final IPath csPath = zipPath.removeFirstSegments(root.segmentCount()); return new CodeSetEntry() { @Override public IPath getPath() { return csPath; } @Override public String toString() { return getPath() + " in " + zipDownload; } @Override public boolean isDirectory() { return e.isDirectory(); } @Override public int getUnixMode() { return e.getUnixMode(); } @Override public InputStream getData() throws IOException { return zip.getInputStream(e); } }; } }