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.hyracks.maven.license; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.io.Writer; import java.net.HttpURLConnection; import java.net.URL; import java.nio.charset.StandardCharsets; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import org.apache.commons.io.IOUtils; import org.apache.maven.plugin.MojoExecutionException; import org.apache.maven.plugin.MojoFailureException; import org.apache.maven.plugins.annotations.LifecyclePhase; import org.apache.maven.plugins.annotations.Mojo; import org.apache.maven.plugins.annotations.Parameter; import org.apache.maven.plugins.annotations.ResolutionScope; import org.apache.maven.project.ProjectBuildingException; @Mojo(name = "licensedownload", requiresProject = true, requiresDependencyResolution = ResolutionScope.TEST, defaultPhase = LifecyclePhase.GENERATE_RESOURCES) public class DownloadLicensesMojo extends LicenseMojo { @Parameter(required = true) private File downloadDir; @Parameter(defaultValue = "30") private int timeoutSecs; @java.lang.Override public void execute() throws MojoExecutionException, MojoFailureException { try { init(); addDependenciesToLicenseMap(); final int timeoutMillis = (int) TimeUnit.SECONDS.toMillis(timeoutSecs); //noinspection ResultOfMethodCallIgnored downloadDir.mkdirs(); AtomicInteger counter = new AtomicInteger(); getLicenseMap().values().parallelStream().forEach(entry -> { final int i = counter.incrementAndGet(); final String url = entry.getLicense().getUrl(); String fileName = entry.getLicense().getContentFile(false); doDownload(timeoutMillis, i, url, fileName); }); } catch (IOException | ProjectBuildingException e) { throw new MojoExecutionException("Unexpected exception: " + e, e); } } private void doDownload(int timeoutMillis, int id, String url, String fileName) { try { HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection(); conn.setConnectTimeout(timeoutMillis); conn.setReadTimeout(timeoutMillis); conn.setRequestMethod("GET"); final File outFile = new File(downloadDir, fileName); getLog().info("[" + id + "] " + url + " -> " + outFile); final InputStream is = conn.getInputStream(); try (FileOutputStream fos = new FileOutputStream(outFile); Writer writer = new OutputStreamWriter(fos, StandardCharsets.UTF_8)) { IOUtils.copy(is, writer, conn.getContentEncoding()); } getLog().info("[" + id + "] ...done!"); } catch (IOException e) { getLog().warn("[" + id + "] ...error downloading " + url + ": " + e); } } }