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.drill.fmpp.mojo; import static java.lang.String.format; import java.io.File; import java.io.IOException; import java.nio.file.Files; import java.util.concurrent.TimeUnit; import org.apache.commons.io.FileUtils; import org.apache.maven.plugin.AbstractMojo; import org.apache.maven.plugin.MojoExecutionException; import org.apache.maven.plugin.MojoFailureException; import org.apache.maven.project.MavenProject; import com.google.common.base.Stopwatch; import fmpp.Engine; import fmpp.ProgressListener; import fmpp.progresslisteners.TerseConsoleProgressListener; import fmpp.setting.Settings; import fmpp.util.MiscUtil; /** * a maven plugin to run the freemarker generation incrementally * (if output has not changed, the files are not touched) * @goal generate * @phase generate-sources */ public class FMPPMojo extends AbstractMojo { /** * Used to add new source directories to the build. * @parameter default-value="${project}" * @required * @readonly **/ private MavenProject project; /** * Where to find the FreeMarker template files. * * @parameter default-value="src/main/resources/fmpp/templates/" * @required */ private File templates; /** * Where to write the generated files of the output files. * * @parameter default-value="${project.build.directory}/generated-sources/fmpp/" * @required */ private File output; /** * Location of the FreeMarker config file. * * @parameter default-value="src/main/resources/fmpp/config.fmpp" * @required */ private File config; /** * compilation scope to be added to ("compile" or "test") * * @parameter default-value="compile" * @required */ private String scope; @Override public void execute() throws MojoExecutionException, MojoFailureException { if (project == null) { throw new MojoExecutionException("This plugin can only be used inside a project."); } String outputPath = output.getAbsolutePath(); if ((!output.exists() && !output.mkdirs()) || !output.isDirectory()) { throw new MojoFailureException("can not write to output dir: " + outputPath); } String templatesPath = templates.getAbsolutePath(); if (!templates.exists() || !templates.isDirectory()) { throw new MojoFailureException("templates not found in dir: " + outputPath); } // add the output directory path to the project source directories switch (scope) { case "compile": project.addCompileSourceRoot(outputPath); break; case "test": project.addTestCompileSourceRoot(outputPath); break; default: throw new MojoFailureException("scope must be compile or test"); } final Stopwatch sw = Stopwatch.createStarted(); try { getLog().info(format("Freemarker generation:\n scope: %s,\n config: %s,\n templates: %s", scope, config.getAbsolutePath(), templatesPath)); final File tmp = Files.createTempDirectory("freemarker-tmp").toFile(); String tmpPath = tmp.getAbsolutePath(); final String tmpPathNormalized = tmpPath.endsWith(File.separator) ? tmpPath : tmpPath + File.separator; Settings settings = new Settings(new File(".")); settings.set("sourceRoot", templatesPath); settings.set("outputRoot", tmp.getAbsolutePath()); settings.load(config); settings.addProgressListener(new TerseConsoleProgressListener()); settings.addProgressListener(new ProgressListener() { @Override public void notifyProgressEvent(Engine engine, int event, File src, int pMode, Throwable error, Object param) throws Exception { if (event == EVENT_END_PROCESSING_SESSION) { getLog().info(format("Freemarker generation took %dms", sw.elapsed(TimeUnit.MILLISECONDS))); sw.reset(); Report report = moveIfChanged(tmp, tmpPathNormalized); if (!tmp.delete()) { throw new MojoFailureException(format("can not delete %s", tmp)); } getLog().info( format("Incremental output update took %dms", sw.elapsed(TimeUnit.MILLISECONDS))); getLog().info(format("new: %d", report.newFiles)); getLog().info(format("changed: %d", report.changedFiles)); getLog().info(format("unchanged: %d", report.unchangedFiles)); } } }); settings.execute(); } catch (Exception e) { throw new MojoFailureException(MiscUtil.causeMessages(e), e); } } private static final class Report { int changedFiles; int unchangedFiles; int newFiles; Report(int changedFiles, int unchangedFiles, int newFiles) { super(); this.changedFiles = changedFiles; this.unchangedFiles = unchangedFiles; this.newFiles = newFiles; } public Report() { this(0, 0, 0); } void add(Report other) { changedFiles += other.changedFiles; unchangedFiles += other.unchangedFiles; newFiles += other.newFiles; } public void addChanged() { ++changedFiles; } public void addNew() { ++newFiles; } public void addUnchanged() { ++unchangedFiles; } } private Report moveIfChanged(File root, String tmpPath) throws MojoFailureException, IOException { Report report = new Report(); for (File file : root.listFiles()) { if (file.isDirectory()) { report.add(moveIfChanged(file, tmpPath)); if (!file.delete()) { throw new MojoFailureException(format("can not delete %s", file)); } } else { String absPath = file.getAbsolutePath(); if (!absPath.startsWith(tmpPath)) { throw new MojoFailureException(format("%s should start with %s", absPath, tmpPath)); } String relPath = absPath.substring(tmpPath.length()); File outputFile = new File(output, relPath); if (!outputFile.exists()) { report.addNew(); } else if (!FileUtils.contentEquals(file, outputFile)) { getLog().info(format("%s has changed", relPath)); if (!outputFile.delete()) { throw new MojoFailureException(format("can not delete %s", outputFile)); } report.addChanged(); } else { report.addUnchanged(); } if (!outputFile.exists()) { File parentDir = outputFile.getParentFile(); if (parentDir.exists() && !parentDir.isDirectory()) { throw new MojoFailureException( format("can not move %s to %s as %s is not a dir", file, outputFile, parentDir)); } if (!parentDir.exists() && !parentDir.mkdirs()) { throw new MojoFailureException(format("can not move %s to %s as dir %s can not be created", file, outputFile, parentDir)); } FileUtils.moveFile(file, outputFile); } else { if (!file.delete()) { throw new MojoFailureException(format("can not delete %s", file)); } } } } return report; } }