nbbuild/antsrc/org/netbeans/nbbuild/extlibs/DownloadBinaries.java - netbeans - Git at Google

 /*
  * 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.netbeans.nbbuild.extlibs;

 import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.math.BigInteger;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.Proxy;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLConnection;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.DirectoryScanner;
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.Task;
 import org.apache.tools.ant.types.FileSet;
 import org.apache.tools.ant.util.FileUtils;

 /**
  * Task to retrieve named files (generally large binaries such as ZIPs) from a repository.
  * Similar to a very simplified version of Ivy, but correctly handles binaries
  * with missing or irrelevant version numbers, since it is based on a hash of contents.
  * You keep one or more manifests under version control which enumerate files and their SHA-1 hashes.
  * Then just run this task to download any missing files.
  * Remember to specify the binaries as "ignorable" to your version control system.
  * You can also run it in a clean mode which will remove the binaries.
  * At the end of this source file is a sample CGI script and matching form which you can run on the server
  * to permit people to upload files to the correct repository paths.
  * Motivation: http://wiki.netbeans.org/wiki/view/HgMigration#section-HgMigration-Binaries
  */
 public class DownloadBinaries extends Task {

     private File cache;
     /**
      * Location of per-user cache of already downloaded binaries.
      * Optional; no cache will be used if unset.
      * The directory will be created if it does not yet exist.
      */
     public void setCache(File cache) {
         this.cache = cache;
     }

     private String server;
     /**
      * URL prefix for the server repository.
      * Should generally include a trailing slash.
      * You may include multiple server URLs separated by spaces
      * in which case they will be tried in order.
      * To use a local repository, simply specify e.g. <code>file:/repo/</code> as the URL.
      */
     public void setServer(String server) {
         this.server = server;
     }

     private final List<FileSet> manifests = new ArrayList<>();
     /**
      * Add one or more manifests of files to download.
      * Each manifest is a text file; lines beginning with # are ignored.
      * All other lines must be entries of the form
      * <pre>
      * 0123456789ABCDEF something-1.0.jar
      * </pre>
      * consisting of an SHA-1 hash followed by a filename.
      * The filename is relative to the manifest, usually a simple basename.
      * If the file exists and has the specified hash, nothing is done.
      * If it has the wrong hash, the task aborts with an error message.
      * If it is missing, it is downloaded from the server (or copied from cache)
      * using a filename derived from the basename of the file in the manifest and its hash.
      * For example, the above line with a server of <code>http://nowhere.net/repo/</code>
      * would try to download
      * <pre>
      * http://nowhere.net/repo/0123456789ABCDEF-something-1.0.jar
      * </pre>
      * Any version number etc. in the filename is purely informational;
      * the "up to date" check is entirely based on the hash.
      */
     public void addManifest(FileSet manifest) {
         manifests.add(manifest);
     }

     private boolean clean;
     /**
      * If true, rather than creating binary files, will delete them.
      * Any cache is ignored in this case.
      * If a binary does not match its hash, the build is aborted:
      * the file might be a precious customized version and should not be blindly deleted.
      */
     public void setClean(boolean clean) {
         this.clean = clean;
     }

     @Override
     public void execute() throws BuildException {
         for (FileSet fs : manifests) {
             DirectoryScanner scanner = fs.getDirectoryScanner(getProject());
             File basedir = scanner.getBasedir();
             for (String include : scanner.getIncludedFiles()) {
                 File manifest = new File(basedir, include);
                 log("Scanning: " + manifest, Project.MSG_VERBOSE);
                 try {
                     try (InputStream is = new FileInputStream(manifest)) {
                         BufferedReader r = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                         String line;
                         while ((line = r.readLine()) != null) {
                             if (line.startsWith("#")) {
                                 continue;
                             }
                             if (line.trim().length() == 0) {
                                 continue;
                             }
                             String[] hashAndFile = line.split(" ", 2);
                             if (hashAndFile.length < 2) {
                                 throw new BuildException("Bad line '" + line + "' in " + manifest, getLocation());
                             }

                             if (MavenCoordinate.isMavenFile(hashAndFile[1])) {
                                 MavenCoordinate mc = MavenCoordinate.fromGradleFormat(hashAndFile[1]);
                                 fillInFile(hashAndFile[0], mc.toArtifactFilename(), manifest, () -> mavenFile(mc));
                             } else {
                                 fillInFile(hashAndFile[0], hashAndFile[1], manifest, () -> legacyDownload(hashAndFile[0] + "-" + hashAndFile[1]));
                             }
                         }
                     }
                 } catch (IOException x) {
                     throw new BuildException("Could not open " + manifest + ": " + x, x, getLocation());
                 }
             }
         }
     }

     private byte[] mavenFile(MavenCoordinate mc) throws IOException {
         String cacheName = mc.toMavenPath();
         File local = new File(new File(new File(new File(System.getProperty("user.home")), ".m2"), "repository"), cacheName.replace('/', File.separatorChar));
         final String url;
         if (local.exists()) {
             url = local.toURI().toString();
         } else {
             url = "https://repo.maven.apache.org/maven2/" + cacheName;
         }
         URL u = new URL(url);
         return downloadFromServer(u);
     }

     private void fillInFile(String expectedHash, String baseName, File manifest, Downloader download) throws BuildException {
         File f = new File(manifest.getParentFile(), baseName);
         if (!clean) {
             if (!f.exists() || !hash(f).equals(expectedHash)) {
                 log("Creating " + f);
                 String cacheName = expectedHash + "-" + baseName;
                 if (cache != null) {
                     cache.mkdirs();
                     File cacheFile = new File(cache, cacheName);
                     if (!cacheFile.exists()) {
                         doDownload(cacheName, cacheFile, expectedHash, download);
                     }
                     if (f.isFile() && !f.delete()) {
                         throw new BuildException("Could not delete " + f);
                     }
                     try {
                         FileUtils.getFileUtils().copyFile(cacheFile, f);
                     } catch (IOException x) {
                         throw new BuildException("Could not copy " + cacheFile + " to " + f + ": " + x, x, getLocation());
                     }
                 } else {
                     doDownload(cacheName, f, expectedHash, download);
                 }
             }
             String actualHash = hash(f);
             if (!actualHash.equals(expectedHash)) {
                 throw new BuildException("File " + f + " requested by " + manifest + " to have hash " +
                         expectedHash + " actually had hash " + actualHash, getLocation());
             }
             log("Have " + f + " with expected hash", Project.MSG_VERBOSE);
         } else {
             if (f.exists()) {
                 String actualHash = hash(f);
                 if (!actualHash.equals(expectedHash)) {
                     throw new BuildException("File " + f + " requested by " + manifest + " to have hash " +
                             expectedHash + " actually had hash " + actualHash, getLocation());
                 }
                 log("Deleting " + f);
                 f.delete();
             }
         }
     }

     private void doDownload(String cacheName, File destination, String expectedHash, Downloader download) {
         Throwable firstProblem = null;
         try {
             byte[] downloaded = download.download();

             if (expectedHash != null) {
                 String actualHash = hash(new ByteArrayInputStream(downloaded));
                 if (!expectedHash.equals(actualHash)) {
                     throw new BuildException("Download of " + cacheName + " produced content with hash "
                             + actualHash + " when " + expectedHash + " was expected", getLocation());
                 }
             }
             OutputStream os = new FileOutputStream(destination);
             try {
                 os.write(downloaded);
             } catch (IOException x) {
                 os.close();
                 destination.delete();
                 throw x;
             }
             os.close();
             return ;
         } catch (IOException x) {
             String msg = "Could not download " + cacheName + " to " + destination + ": " + x;
             log(msg, Project.MSG_WARN);
             if (firstProblem == null) {
                 firstProblem = new IOException(msg).initCause(x);
             }
         }
         throw new BuildException("Could not download " + cacheName + " from " + server + ": " + firstProblem, firstProblem, getLocation());
     }

     private byte[] legacyDownload(String cacheName) throws IOException {
         if (server == null) {
             throw new BuildException("Must specify a server to download files from", getLocation());
         }
         Throwable firstProblem = null;
         for (String prefix : server.split(" ")) {
             URL url = new URL(prefix + cacheName);
             return downloadFromServer(url);
         }
         throw new BuildException("Could not download " + cacheName + " from " + server + ": " + firstProblem, firstProblem, getLocation());
     }

     private byte[] downloadFromServer(URL url) throws IOException {
         log("Downloading: " + url);
         URLConnection conn = openConnection(url);
         int code = HttpURLConnection.HTTP_OK;
         if (conn instanceof HttpURLConnection) {
             code = ((HttpURLConnection) conn).getResponseCode();
         }
         if (code != HttpURLConnection.HTTP_OK) {
             throw new IOException("Skipping download from " + url + " due to response code " + code);
         }
         try {
             try (InputStream is = conn.getInputStream()) {
                 ByteArrayOutputStream baos = new ByteArrayOutputStream();
                 byte[] buf = new byte[4096];
                 int read;
                 while ((read = is.read(buf)) != -1) {
                     baos.write(buf, 0, read);
                 }
                 return baos.toByteArray();
             }
         } catch (IOException ex) {
             throw new IOException("Cannot download: " + url + " due to: " + ex, ex);
         }
     }

     interface Downloader {
         public byte[] download() throws IOException;
     }

     private URLConnection openConnection(final URL url) throws IOException {
         final URLConnection[] conn = { null };
         final CountDownLatch connected = new CountDownLatch(1);
         ExecutorService connectors = Executors.newFixedThreadPool(3);
         connectors.submit(new Runnable() {
             public void run() {
                 String httpProxy = System.getenv("http_proxy");
                 if (httpProxy != null) {
                     try {
                         URI uri = new URI(httpProxy);
                         InetSocketAddress address = InetSocketAddress.createUnresolved(uri.getHost(), uri.getPort());
                         Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
                         URLConnection test = url.openConnection(proxy);
                         test.connect();
                         conn[0] = test;
                         connected.countDown();
                     } catch (IOException | URISyntaxException ex) {
                         log(ex, Project.MSG_ERR);
                     }
                 }
             }
         });
         connectors.submit(new Runnable() {
             public void run() {
                 String httpProxy = System.getenv("https_proxy");
                 if (httpProxy != null) {
                     try {
                         URI uri = new URI(httpProxy);
                         InetSocketAddress address = InetSocketAddress.createUnresolved(uri.getHost(), uri.getPort());
                         Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
                         URLConnection test = url.openConnection(proxy);
                         test.connect();
                         conn[0] = test;
                         connected.countDown();
                     } catch (IOException | URISyntaxException ex) {
                         log(ex, Project.MSG_ERR);
                     }
                 }
             }
         });
         connectors.submit(new Runnable() {
             public void run() {
                 try {
                     URLConnection test = url.openConnection();
                     test.connect();
                     conn[0] = test;
                     connected.countDown();
                 } catch (IOException ex) {
                     log(ex, Project.MSG_ERR);
                 }
             }
         });
         try {
             connected.await(5, TimeUnit.SECONDS);
         } catch (InterruptedException ex) {
         }
         if (conn[0] == null) {
             throw new IOException("Cannot connect to " + url);
         }
         return conn[0];
     }

     private String hash(File f) {
         try {
             try (FileInputStream is = new FileInputStream(f)) {
                 return hash(is);
             }
         } catch (IOException x) {
             throw new BuildException("Could not get hash for " + f + ": " + x, x, getLocation());
         }
     }

     private String hash(InputStream is) throws IOException {
         MessageDigest digest;
         try {
             digest = MessageDigest.getInstance("SHA-1");
         } catch (NoSuchAlgorithmException x) {
             throw new BuildException(x, getLocation());
         }
         byte[] buf = new byte[4096];
         int r;
         while ((r = is.read(buf)) != -1) {
             digest.update(buf, 0, r);
         }
         return String.format("%040X", new BigInteger(1, digest.digest()));
     }

     static class MavenCoordinate {
         private final String groupId;
         private final String artifactId;
         private final String version;
         private final String extension;
         private final String classifier;

         private MavenCoordinate(String groupId, String artifactId, String version, String extension, String classifier) {
             this.groupId = groupId;
             this.artifactId = artifactId;
             this.version = version;
             this.extension = extension;
             this.classifier = classifier;
         }

         public boolean hasClassifier() {
             return (! classifier.isEmpty());
         }

         public String getGroupId() {
             return groupId;
         }

         public String getArtifactId() {
             return artifactId;
         }

         public String getVersion() {
             return version;
         }

         public String getExtension() {
             return extension;
         }

         public String getClassifier() {
             return classifier;
         }

         /**
          * @return filename of the artifact by maven convention:
          *         {@code artifact-version[-classifier].extension}
          */
         public String toArtifactFilename() {
             return String.format("%s-%s%s.%s",
                     getArtifactId(),
                     getVersion(),
                     hasClassifier() ? ("-" + getClassifier()) : "",
                     getExtension()
             );
         }

         /**
          * @return The repository path for an artifact by maven convention:
          *         {@code group/artifact/version/artifact-version[-classifier].extension}.
          *         In the group part all dots are replaced by a slash.
          */
         public String toMavenPath() {
             return String.format("%s/%s/%s/%s",
                     getGroupId().replace(".", "/"),
                     getArtifactId(),
                     getVersion(),
                     toArtifactFilename()
                     );
         }

         public static boolean isMavenFile(String gradleFormat) {
             return gradleFormat.split(":").length > 2;
         }

         /**
          * The maven coordinate is supplied in the form:
          *
          * <p>{@code group:name:version:classifier@extension}</p>
          *
          * <p>For the DownloadBinaries task the parts group, name and version
          * are requiered. classifier and extension are optional. The extension
          * has a default value of "jar".
          *
          * @param gradleFormat artifact coordinated to be parse as a MavenCoordinate
          * @return
          * @throws IllegalArgumentException if provided string fails to parse
          */
         public static MavenCoordinate fromGradleFormat(String gradleFormat) {
             if(! isMavenFile(gradleFormat)) {
                 throw new IllegalArgumentException("Supplied string is not in gradle dependency format: " + gradleFormat);
             }
             String[] coordinateExtension = gradleFormat.split("@", 2);
             String extension;
             String coordinate = coordinateExtension[0];
             if (coordinateExtension.length > 1
                     && (!coordinateExtension[1].trim().isEmpty())) {
                 extension = coordinateExtension[1];
             } else {
                 extension = "jar";
             }
             String[] coordinates = coordinate.split(":");
             String group = coordinates[0];
             String artifact = coordinates[1];
             String version = coordinates[2];
             String classifier = "";
             if (coordinates.length > 3) {
                 classifier = coordinates[3].trim();
             }
             return new MavenCoordinate(group, artifact, version, extension, classifier);
         }
     }
 }

 /*

 Sample upload script (edit repository location as needed):

 #!/usr/bin/env ruby
 repository = '/tmp/repository'
 require 'cgi'
 require 'digest/sha1'
 require 'date'
 cgi = CGI.new
 begin
   if cgi.request_method == 'POST'
     value = cgi['file']
     content = value.read
     name = value.original_filename.gsub(/\.\.|[^a-zA-Z0-9._+-]/, '_')
     sha1 = Digest::SHA1.hexdigest(content).upcase
     open("#{repository}/#{sha1}-#{name}", "w") do |f|
       f.write content
     end
     open("#{repository}/log", "a") do |f|
       f << "#{DateTime.now.to_s} #{sha1}-#{name} #{cgi.remote_user}\n"
     end
     cgi.out do <<RESPONSE
 <html>
 <head>
 <title>Uploaded #{name}</title>
 </head>
 <body>
 <p>Uploaded. Add to your manifest:</p>
 <pre>#{sha1} #{name}</pre>
 </body>
 </html>
 RESPONSE
     end
   else
     cgi.out do <<FORM
 <html>
 <head>
 <title>Upload a Binary</title>
 </head>
 <body>
 <form method="POST" action="" enctype="multipart/form-data">
 <input type="file" name="file">
 <input type="submit" value="Upload">
 </form>
 </body>
 </html>
 FORM
     end
   end
 rescue
   cgi.out do
     "Caught an exception: #{$!}"
   end
 end

  */
	/*
	* 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.netbeans.nbbuild.extlibs;

	import java.io.BufferedReader;
	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.OutputStream;
	import java.math.BigInteger;
	import java.net.HttpURLConnection;
	import java.net.InetSocketAddress;
	import java.net.Proxy;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.net.URL;
	import java.net.URLConnection;
	import java.security.MessageDigest;
	import java.security.NoSuchAlgorithmException;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.concurrent.CountDownLatch;
	import java.util.concurrent.ExecutorService;
	import java.util.concurrent.Executors;
	import java.util.concurrent.TimeUnit;
	import org.apache.tools.ant.BuildException;
	import org.apache.tools.ant.DirectoryScanner;
	import org.apache.tools.ant.Project;
	import org.apache.tools.ant.Task;
	import org.apache.tools.ant.types.FileSet;
	import org.apache.tools.ant.util.FileUtils;

	/**
	* Task to retrieve named files (generally large binaries such as ZIPs) from a repository.
	* Similar to a very simplified version of Ivy, but correctly handles binaries
	* with missing or irrelevant version numbers, since it is based on a hash of contents.
	* You keep one or more manifests under version control which enumerate files and their SHA-1 hashes.
	* Then just run this task to download any missing files.
	* Remember to specify the binaries as "ignorable" to your version control system.
	* You can also run it in a clean mode which will remove the binaries.
	* At the end of this source file is a sample CGI script and matching form which you can run on the server
	* to permit people to upload files to the correct repository paths.
	* Motivation: http://wiki.netbeans.org/wiki/view/HgMigration#section-HgMigration-Binaries
	*/
	public class DownloadBinaries extends Task {

	private File cache;
	/**
	* Location of per-user cache of already downloaded binaries.
	* Optional; no cache will be used if unset.
	* The directory will be created if it does not yet exist.
	*/
	public void setCache(File cache) {
	this.cache = cache;
	}

	private String server;
	/**
	* URL prefix for the server repository.
	* Should generally include a trailing slash.
	* You may include multiple server URLs separated by spaces
	* in which case they will be tried in order.
	* To use a local repository, simply specify e.g. <code>file:/repo/</code> as the URL.
	*/
	public void setServer(String server) {
	this.server = server;
	}

	private final List<FileSet> manifests = new ArrayList<>();
	/**
	* Add one or more manifests of files to download.
	* Each manifest is a text file; lines beginning with # are ignored.
	* All other lines must be entries of the form
	* <pre>
	* 0123456789ABCDEF something-1.0.jar
	* </pre>
	* consisting of an SHA-1 hash followed by a filename.
	* The filename is relative to the manifest, usually a simple basename.
	* If the file exists and has the specified hash, nothing is done.
	* If it has the wrong hash, the task aborts with an error message.
	* If it is missing, it is downloaded from the server (or copied from cache)
	* using a filename derived from the basename of the file in the manifest and its hash.
	* For example, the above line with a server of <code>http://nowhere.net/repo/</code>
	* would try to download
	* <pre>
	* http://nowhere.net/repo/0123456789ABCDEF-something-1.0.jar
	* </pre>
	* Any version number etc. in the filename is purely informational;
	* the "up to date" check is entirely based on the hash.
	*/
	public void addManifest(FileSet manifest) {
	manifests.add(manifest);
	}

	private boolean clean;
	/**
	* If true, rather than creating binary files, will delete them.
	* Any cache is ignored in this case.
	* If a binary does not match its hash, the build is aborted:
	* the file might be a precious customized version and should not be blindly deleted.
	*/
	public void setClean(boolean clean) {
	this.clean = clean;
	}

	@Override
	public void execute() throws BuildException {
	for (FileSet fs : manifests) {
	DirectoryScanner scanner = fs.getDirectoryScanner(getProject());
	File basedir = scanner.getBasedir();
	for (String include : scanner.getIncludedFiles()) {
	File manifest = new File(basedir, include);
	log("Scanning: " + manifest, Project.MSG_VERBOSE);
	try {
	try (InputStream is = new FileInputStream(manifest)) {
	BufferedReader r = new BufferedReader(new InputStreamReader(is, "UTF-8"));
	String line;
	while ((line = r.readLine()) != null) {
	if (line.startsWith("#")) {
	continue;
	}
	if (line.trim().length() == 0) {
	continue;
	}
	String[] hashAndFile = line.split(" ", 2);
	if (hashAndFile.length < 2) {
	throw new BuildException("Bad line '" + line + "' in " + manifest, getLocation());
	}

	if (MavenCoordinate.isMavenFile(hashAndFile[1])) {
	MavenCoordinate mc = MavenCoordinate.fromGradleFormat(hashAndFile[1]);
	fillInFile(hashAndFile[0], mc.toArtifactFilename(), manifest, () -> mavenFile(mc));
	} else {
	fillInFile(hashAndFile[0], hashAndFile[1], manifest, () -> legacyDownload(hashAndFile[0] + "-" + hashAndFile[1]));
	}
	}
	}
	} catch (IOException x) {
	throw new BuildException("Could not open " + manifest + ": " + x, x, getLocation());
	}
	}
	}
	}

	private byte[] mavenFile(MavenCoordinate mc) throws IOException {
	String cacheName = mc.toMavenPath();
	File local = new File(new File(new File(new File(System.getProperty("user.home")), ".m2"), "repository"), cacheName.replace('/', File.separatorChar));
	final String url;
	if (local.exists()) {
	url = local.toURI().toString();
	} else {
	url = "https://repo.maven.apache.org/maven2/" + cacheName;
	}
	URL u = new URL(url);
	return downloadFromServer(u);
	}

	private void fillInFile(String expectedHash, String baseName, File manifest, Downloader download) throws BuildException {
	File f = new File(manifest.getParentFile(), baseName);
	if (!clean) {
	if (!f.exists() \|\| !hash(f).equals(expectedHash)) {
	log("Creating " + f);
	String cacheName = expectedHash + "-" + baseName;
	if (cache != null) {
	cache.mkdirs();
	File cacheFile = new File(cache, cacheName);
	if (!cacheFile.exists()) {
	doDownload(cacheName, cacheFile, expectedHash, download);
	}
	if (f.isFile() && !f.delete()) {
	throw new BuildException("Could not delete " + f);
	}
	try {
	FileUtils.getFileUtils().copyFile(cacheFile, f);
	} catch (IOException x) {
	throw new BuildException("Could not copy " + cacheFile + " to " + f + ": " + x, x, getLocation());
	}
	} else {
	doDownload(cacheName, f, expectedHash, download);
	}
	}
	String actualHash = hash(f);
	if (!actualHash.equals(expectedHash)) {
	throw new BuildException("File " + f + " requested by " + manifest + " to have hash " +
	expectedHash + " actually had hash " + actualHash, getLocation());
	}
	log("Have " + f + " with expected hash", Project.MSG_VERBOSE);
	} else {
	if (f.exists()) {
	String actualHash = hash(f);
	if (!actualHash.equals(expectedHash)) {
	throw new BuildException("File " + f + " requested by " + manifest + " to have hash " +
	expectedHash + " actually had hash " + actualHash, getLocation());
	}
	log("Deleting " + f);
	f.delete();
	}
	}
	}

	private void doDownload(String cacheName, File destination, String expectedHash, Downloader download) {
	Throwable firstProblem = null;
	try {
	byte[] downloaded = download.download();

	if (expectedHash != null) {
	String actualHash = hash(new ByteArrayInputStream(downloaded));
	if (!expectedHash.equals(actualHash)) {
	throw new BuildException("Download of " + cacheName + " produced content with hash "
	+ actualHash + " when " + expectedHash + " was expected", getLocation());
	}
	}
	OutputStream os = new FileOutputStream(destination);
	try {
	os.write(downloaded);
	} catch (IOException x) {
	os.close();
	destination.delete();
	throw x;
	}
	os.close();
	return ;
	} catch (IOException x) {
	String msg = "Could not download " + cacheName + " to " + destination + ": " + x;
	log(msg, Project.MSG_WARN);
	if (firstProblem == null) {
	firstProblem = new IOException(msg).initCause(x);
	}
	}
	throw new BuildException("Could not download " + cacheName + " from " + server + ": " + firstProblem, firstProblem, getLocation());
	}

	private byte[] legacyDownload(String cacheName) throws IOException {
	if (server == null) {
	throw new BuildException("Must specify a server to download files from", getLocation());
	}
	Throwable firstProblem = null;
	for (String prefix : server.split(" ")) {
	URL url = new URL(prefix + cacheName);
	return downloadFromServer(url);
	}
	throw new BuildException("Could not download " + cacheName + " from " + server + ": " + firstProblem, firstProblem, getLocation());
	}

	private byte[] downloadFromServer(URL url) throws IOException {
	log("Downloading: " + url);
	URLConnection conn = openConnection(url);
	int code = HttpURLConnection.HTTP_OK;
	if (conn instanceof HttpURLConnection) {
	code = ((HttpURLConnection) conn).getResponseCode();
	}
	if (code != HttpURLConnection.HTTP_OK) {
	throw new IOException("Skipping download from " + url + " due to response code " + code);
	}
	try {
	try (InputStream is = conn.getInputStream()) {
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	byte[] buf = new byte[4096];
	int read;
	while ((read = is.read(buf)) != -1) {
	baos.write(buf, 0, read);
	}
	return baos.toByteArray();
	}
	} catch (IOException ex) {
	throw new IOException("Cannot download: " + url + " due to: " + ex, ex);
	}
	}

	interface Downloader {
	public byte[] download() throws IOException;
	}

	private URLConnection openConnection(final URL url) throws IOException {
	final URLConnection[] conn = { null };
	final CountDownLatch connected = new CountDownLatch(1);
	ExecutorService connectors = Executors.newFixedThreadPool(3);
	connectors.submit(new Runnable() {
	public void run() {
	String httpProxy = System.getenv("http_proxy");
	if (httpProxy != null) {
	try {
	URI uri = new URI(httpProxy);
	InetSocketAddress address = InetSocketAddress.createUnresolved(uri.getHost(), uri.getPort());
	Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
	URLConnection test = url.openConnection(proxy);
	test.connect();
	conn[0] = test;
	connected.countDown();
	} catch (IOException \| URISyntaxException ex) {
	log(ex, Project.MSG_ERR);
	}
	}
	}
	});
	connectors.submit(new Runnable() {
	public void run() {
	String httpProxy = System.getenv("https_proxy");
	if (httpProxy != null) {
	try {
	URI uri = new URI(httpProxy);
	InetSocketAddress address = InetSocketAddress.createUnresolved(uri.getHost(), uri.getPort());
	Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
	URLConnection test = url.openConnection(proxy);
	test.connect();
	conn[0] = test;
	connected.countDown();
	} catch (IOException \| URISyntaxException ex) {
	log(ex, Project.MSG_ERR);
	}
	}
	}
	});
	connectors.submit(new Runnable() {
	public void run() {
	try {
	URLConnection test = url.openConnection();
	test.connect();
	conn[0] = test;
	connected.countDown();
	} catch (IOException ex) {
	log(ex, Project.MSG_ERR);
	}
	}
	});
	try {
	connected.await(5, TimeUnit.SECONDS);
	} catch (InterruptedException ex) {
	}
	if (conn[0] == null) {
	throw new IOException("Cannot connect to " + url);
	}
	return conn[0];
	}

	private String hash(File f) {
	try {
	try (FileInputStream is = new FileInputStream(f)) {
	return hash(is);
	}
	} catch (IOException x) {
	throw new BuildException("Could not get hash for " + f + ": " + x, x, getLocation());
	}
	}

	private String hash(InputStream is) throws IOException {
	MessageDigest digest;
	try {
	digest = MessageDigest.getInstance("SHA-1");
	} catch (NoSuchAlgorithmException x) {
	throw new BuildException(x, getLocation());
	}
	byte[] buf = new byte[4096];
	int r;
	while ((r = is.read(buf)) != -1) {
	digest.update(buf, 0, r);
	}
	return String.format("%040X", new BigInteger(1, digest.digest()));
	}

	static class MavenCoordinate {
	private final String groupId;
	private final String artifactId;
	private final String version;
	private final String extension;
	private final String classifier;

	private MavenCoordinate(String groupId, String artifactId, String version, String extension, String classifier) {
	this.groupId = groupId;
	this.artifactId = artifactId;
	this.version = version;
	this.extension = extension;
	this.classifier = classifier;
	}

	public boolean hasClassifier() {
	return (! classifier.isEmpty());
	}

	public String getGroupId() {
	return groupId;
	}

	public String getArtifactId() {
	return artifactId;
	}

	public String getVersion() {
	return version;
	}

	public String getExtension() {
	return extension;
	}

	public String getClassifier() {
	return classifier;
	}

	/**
	* @return filename of the artifact by maven convention:
	* {@code artifact-version[-classifier].extension}
	*/
	public String toArtifactFilename() {
	return String.format("%s-%s%s.%s",
	getArtifactId(),
	getVersion(),
	hasClassifier() ? ("-" + getClassifier()) : "",
	getExtension()
	);
	}

	/**
	* @return The repository path for an artifact by maven convention:
	* {@code group/artifact/version/artifact-version[-classifier].extension}.
	* In the group part all dots are replaced by a slash.
	*/
	public String toMavenPath() {
	return String.format("%s/%s/%s/%s",
	getGroupId().replace(".", "/"),
	getArtifactId(),
	getVersion(),
	toArtifactFilename()
	);
	}

	public static boolean isMavenFile(String gradleFormat) {
	return gradleFormat.split(":").length > 2;
	}

	/**
	* The maven coordinate is supplied in the form:
	*
	* <p>{@code group:name:version:classifier@extension}</p>
	*
	* <p>For the DownloadBinaries task the parts group, name and version
	* are requiered. classifier and extension are optional. The extension
	* has a default value of "jar".
	*
	* @param gradleFormat artifact coordinated to be parse as a MavenCoordinate
	* @return
	* @throws IllegalArgumentException if provided string fails to parse
	*/
	public static MavenCoordinate fromGradleFormat(String gradleFormat) {
	if(! isMavenFile(gradleFormat)) {
	throw new IllegalArgumentException("Supplied string is not in gradle dependency format: " + gradleFormat);
	}
	String[] coordinateExtension = gradleFormat.split("@", 2);
	String extension;
	String coordinate = coordinateExtension[0];
	if (coordinateExtension.length > 1
	&& (!coordinateExtension[1].trim().isEmpty())) {
	extension = coordinateExtension[1];
	} else {
	extension = "jar";
	}
	String[] coordinates = coordinate.split(":");
	String group = coordinates[0];
	String artifact = coordinates[1];
	String version = coordinates[2];
	String classifier = "";
	if (coordinates.length > 3) {
	classifier = coordinates[3].trim();
	}
	return new MavenCoordinate(group, artifact, version, extension, classifier);
	}
	}
	}

	/*

	Sample upload script (edit repository location as needed):

	#!/usr/bin/env ruby
	repository = '/tmp/repository'
	require 'cgi'
	require 'digest/sha1'
	require 'date'
	cgi = CGI.new
	begin
	if cgi.request_method == 'POST'
	value = cgi['file']
	content = value.read
	name = value.original_filename.gsub(/\.\.\|[^a-zA-Z0-9._+-]/, '_')
	sha1 = Digest::SHA1.hexdigest(content).upcase
	open("#{repository}/#{sha1}-#{name}", "w") do \|f\|
	f.write content
	end
	open("#{repository}/log", "a") do \|f\|
	f << "#{DateTime.now.to_s} #{sha1}-#{name} #{cgi.remote_user}\n"
	end
	cgi.out do <<RESPONSE
	<html>
	<head>
	<title>Uploaded #{name}</title>
	</head>
	<body>
	<p>Uploaded. Add to your manifest:</p>
	<pre>#{sha1} #{name}</pre>
	</body>
	</html>
	RESPONSE
	end
	else
	cgi.out do <<FORM
	<html>
	<head>
	<title>Upload a Binary</title>
	</head>
	<body>
	<form method="POST" action="" enctype="multipart/form-data">
	<input type="file" name="file">
	<input type="submit" value="Upload">
	</form>
	</body>
	</html>
	FORM
	end
	end
	rescue
	cgi.out do
	"Caught an exception: #{$!}"
	end
	end

	*/