Java tutorial
/******************************************************************************* * * Copyright 2011 Spiffy UI Team * * Licensed 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.spiffyui.maven.plugins; import java.io.File; import java.util.ArrayList; import java.util.List; import javax.tools.JavaCompiler; import javax.tools.ToolProvider; 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; /** * Invokes the Java compiler for the project .java source * * @goal java-compile * @phase process-classes * @requiresDependencyResolution compile */ public class JavaCompileMojo extends AbstractMojo { /** * @parameter default-value="${project}" * @required * @readonly */ private MavenProject project; /** * Enable debug output * * @parameter expression="${spiffyui.javac.debug}" default-value=true */ private boolean debug; /** * Enable verbose output * * @parameter expression="${spiffyui.javac.verbose}" default-value=false */ private boolean verbose; /** * Enable deprecation warnings * * @parameter expression="${spiffyui.javac.deprecation}" default-value=false */ private boolean deprecation; /** * Disable warnings * * @parameter expression="${spiffyui.javac.nowarn}" default-value=false */ private boolean nowarn; /** * Set Xlint value passed to compiler "all" = enable all "none" = disable * all $value = pass to compiler as -Xlint:$value * * @parameter expression="${spiffyui.javac.xlint}" default-value=none */ private String xlint; /** * Extra arguments to pass to the compiler * * @parameter expression="${spiffyui.javac.extraArgs}" */ private List<String> extraArgs; /** * The -source argument for the Java compiler. * * @parameter expression="${spiffyui.javac.source}" default-value="1.6" */ private String source; /** * The -target argument for the Java compiler. * * @parameter expression="${spiffyui.javac.target}" default-value="1.6" */ private String target; /** * The source directories containing the sources to be compiled. * * @parameter default-value="${project.compileSourceRoots}" * @required * @readonly */ private List<String> compileSourceRoots; /** * The path to our generated source * * @parameter expression="${spiffyui.generated-source}" * @required * @readonly */ private String generatedSourcePath; /** * Project classpath. * * @parameter default-value="${project.compileClasspathElements}" * @required * @readonly */ private List<String> classpathElements; /** * The character encoding scheme to be applied when filtering resources. * * @parameter expression="${project.build.sourceEncoding}" * default-value="UTF-8" */ private String encoding; /** * The output directory into which to copy the resources. * * @parameter default-value="${project.build.outputDirectory}" * @required */ private File outputDirectory; /** * <p> * Specify where to place generated source files created by annotation * processing. Only applies to JDK 1.6+ * </p> * * @parameter * default-value="${project.build.directory}/generated-sources/annotations" */ private File generatedSourcesDirectory; /** * Convenience class that makes it easier to build a string of arguments for * passing to the compiler */ class ArgBuilder { private List<String> m_args = new ArrayList<String>(); ArgBuilder add(String arg) { m_args.add(arg); return this; } @Override public String toString() { return flatten(m_args.toString(), " "); } public String[] get() { return m_args.toArray(new String[m_args.size()]); } } @Override public void execute() throws MojoExecutionException, MojoFailureException { ArgBuilder args = new ArgBuilder(); String classpath = flatten(classpathElements.toString(), File.pathSeparator); if (debug) { args.add("-g"); } if (verbose) { args.add("-verbose"); } if (deprecation) { args.add("-deprecation"); } if (nowarn) { args.add("-nowarn"); } if (!xlint.equals("none")) { if (xlint.equals("all")) { args.add("-Xlint"); } else { args.add("-Xlint:" + xlint); } } args.add("-d").add(outputDirectory.getAbsolutePath()).add("-s") .add(generatedSourcesDirectory.getAbsolutePath()).add("-encoding").add(encoding).add("-cp") .add(classpath).add("-source").add(source).add("-target").add(target); String[] exts = { "java" }; for (String extraArg : extraArgs) { args.add(extraArg); } List<String> sources = compileSourceRoots; sources.add(generatedSourcePath); for (String s : sources) { File path = new File(s); if (!path.exists()) { continue; } List<File> files = new ArrayList<File>(FileUtils.listFiles(path, exts, true)); for (File file : files) { args.add(file.getAbsolutePath()); } } ensureExists(outputDirectory); ensureExists(generatedSourcesDirectory); JavaCompiler javac = ToolProvider.getSystemJavaCompiler(); if (javac == null) { throw new MojoExecutionException("The Java compiler could not be found. " + "Make sure to point your Maven build to a full Java development environment."); } getLog().debug("Exec: javac " + args.toString()); if (javac.run(null, null, null, args.get()) != 0) { throw new MojoExecutionException("Compilation failed"); } } private void ensureExists(File dir) { if (!dir.exists()) { dir.mkdirs(); } } private String flatten(String list, String sep) { return list.replace(", ", sep).replace("[", "").replace("]", ""); } }