Coalesce JavaBuilder class hierarchy

Some of these abstract classes used to have more than one subtype.

--
PiperOrigin-RevId: 144366452
MOS_MIGRATED_REVID=144366452

4 files changed, 359 insertions, 452 deletions

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java
deleted file mode 100644
index 6973c320d1..0000000000
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java
+++ /dev/null
@@ -1,159 +0,0 @@
-// Copyright 2014 The Bazel Authors. All rights reserved.
-//
-// 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 com.google.devtools.build.buildjar;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.io.Files;
-import com.google.devtools.build.buildjar.instrumentation.JacocoInstrumentationProcessor;
-import com.google.devtools.build.buildjar.javac.BlazeJavacArguments;
-import com.google.devtools.build.buildjar.javac.BlazeJavacMain;
-import com.google.devtools.build.buildjar.javac.JavacRunner;
-import com.google.devtools.build.buildjar.javac.plugins.BlazeJavaCompilerPlugin;
-import com.sun.tools.javac.main.Main.Result;
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.OutputStream;
-import java.io.PrintWriter;
-import java.util.List;
-import java.util.zip.ZipEntry;
-
-/**
- * A command line interface to compile a java_library rule using in-process javac. This allows us to
- * spawn multiple java_library compilations on a single machine or distribute Java compilations to
- * multiple machines.
- */
-public abstract class AbstractJavaBuilder extends AbstractLibraryBuilder {
-
-  /** The name of the protobuf meta file. */
-  private static final String PROTOBUF_META_NAME = "protobuf.meta";
-
-  /** Enables more verbose output from the compiler. */
-  protected boolean debug = false;
-
-  /**
-   * Prepares a compilation run and sets everything up so that the source files in the build request
-   * can be compiled. Invokes compileSources to do the actual compilation.
-   *
-   * @param build A JavaLibraryBuildRequest request object describing what to compile
-   * @param err PrintWriter for logging any diagnostic output
-   */
-  public Result compileJavaLibrary(final JavaLibraryBuildRequest build, final PrintWriter err)
-      throws Exception {
-    prepareSourceCompilation(build);
-    if (build.getSourceFiles().isEmpty()) {
-      return Result.OK;
-    }
-    JavacRunner javacRunner =
-        new JavacRunner() {
-          @Override
-          public Result invokeJavac(
-              ImmutableList<BlazeJavaCompilerPlugin> plugins,
-              BlazeJavacArguments arguments,
-              PrintWriter output) {
-            return new BlazeJavacMain(output, plugins).compile(arguments);
-          }
-        };
-    Result result = compileSources(build, javacRunner, err);
-    JacocoInstrumentationProcessor processor = build.getJacocoInstrumentationProcessor();
-    if (processor != null) {
-      processor.processRequest(build);
-    }
-    return result;
-  }
-
-  /** Build a jar file containing source files that were generated by an annotation processor. */
-  public abstract void buildGensrcJar(JavaLibraryBuildRequest build) throws IOException;
-
-  /**
-   * Compiles the java files specified in 'JavaLibraryBuildRequest'. Implementations can try to
-   * avoid recompiling the java files. Whenever this function is invoked, it is guaranteed that the
-   * build request contains files to compile.
-   *
-   * @param build A JavaLibraryBuildRequest request object describing what to compile
-   * @param err PrintWriter for logging any diagnostic output
-   * @return the exit status of the java compiler.
-   */
-  abstract Result compileSources(
-      JavaLibraryBuildRequest build, JavacRunner javacRunner, PrintWriter err) throws IOException;
-
-  /** Perform the build. */
-  public Result run(JavaLibraryBuildRequest build, PrintWriter err) throws Exception {
-    Result result = Result.ERROR;
-    try {
-      result = compileJavaLibrary(build, err);
-      if (result.isOK()) {
-        buildJar(build);
-      }
-      if (!build.getProcessors().isEmpty()) {
-        if (build.getGeneratedSourcesOutputJar() != null) {
-          buildGensrcJar(build);
-        }
-      }
-    } finally {
-      build.getDependencyModule().emitDependencyInformation(build.getClassPath(), result.isOK());
-      build.getProcessingModule().emitManifestProto();
-    }
-    return result;
-  }
-
-  /** A SourceJarEntryListener that collects protobuf meta data files from the source jar files. */
-  private static class ProtoMetaFileCollector implements SourceJarEntryListener {
-
-    private final String sourceDir;
-    private final String outputDir;
-    private final ByteArrayOutputStream buffer;
-
-    public ProtoMetaFileCollector(String sourceDir, String outputDir) {
-      this.sourceDir = sourceDir;
-      this.outputDir = outputDir;
-      this.buffer = new ByteArrayOutputStream();
-    }
-
-    @Override
-    public void onEntry(ZipEntry entry) throws IOException {
-      String entryName = entry.getName();
-      if (!entryName.equals(PROTOBUF_META_NAME)) {
-        return;
-      }
-      Files.copy(new File(sourceDir, PROTOBUF_META_NAME), buffer);
-    }
-
-    /**
-     * Writes the combined the meta files into the output directory. Delete the stalling meta file
-     * if no meta file is collected.
-     */
-    @Override
-    public void finish() throws IOException {
-      File outputFile = new File(outputDir, PROTOBUF_META_NAME);
-      if (buffer.size() > 0) {
-        try (OutputStream outputStream = new FileOutputStream(outputFile)) {
-          buffer.writeTo(outputStream);
-        }
-      } else if (outputFile.exists()) {
-        // Delete stalled meta file.
-        outputFile.delete();
-      }
-    }
-  }
-
-  @Override
-  protected List<SourceJarEntryListener> getSourceJarEntryListeners(JavaLibraryBuildRequest build) {
-    List<SourceJarEntryListener> result = super.getSourceJarEntryListeners(build);
-    result.add(new ProtoMetaFileCollector(build.getTempDir(), build.getClassDir()));
-    return result;
-  }
-}
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractLibraryBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractLibraryBuilder.java
deleted file mode 100644
index efac18a705..0000000000
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractLibraryBuilder.java
+++ /dev/null
@@ -1,287 +0,0 @@
-// Copyright 2014 The Bazel Authors. All rights reserved.
-//
-// 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 com.google.devtools.build.buildjar;
-
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.io.ByteStreams;
-import com.google.devtools.build.buildjar.jarhelper.JarCreator;
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Enumeration;
-import java.util.List;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
-
-/**
- * Base class for java_library builders.
- *
- * <p>Implements common functionality like source files preparation and output jar creation.
- */
-public abstract class AbstractLibraryBuilder {
-
-  /**
-   * Prepares a compilation run. This involves cleaning up temporary directories and writing the
-   * classpath files.
-   */
-  protected void prepareSourceCompilation(JavaLibraryBuildRequest build) throws IOException {
-    File classDirectory = new File(build.getClassDir());
-    if (classDirectory.exists()) {
-      try {
-        // Necessary for local builds in order to discard previous outputs
-        cleanupOutputDirectory(classDirectory);
-      } catch (IOException e) {
-        throw new IOException("Cannot clean output directory '" + classDirectory + "'", e);
-      }
-    }
-    classDirectory.mkdirs();
-
-    setUpSourceJars(build);
-  }
-
-  public void buildJar(JavaLibraryBuildRequest build) throws IOException {
-    JarCreator jar = new JarCreator(build.getOutputJar());
-    jar.setNormalize(true);
-    jar.setCompression(build.compressJar());
-
-    // The easiest way to handle resource jars is to unpack them into the class directory, just
-    // before we start zipping it up.
-    for (String resourceJar : build.getResourceJars()) {
-      setUpSourceJar(
-          new File(resourceJar), build.getClassDir(), new ArrayList<SourceJarEntryListener>());
-    }
-
-    jar.addDirectory(build.getClassDir());
-
-    jar.addRootEntries(build.getRootResourceFiles());
-    addResourceEntries(jar, build.getResourceFiles());
-    addMessageEntries(jar, build.getMessageFiles());
-
-    jar.execute();
-  }
-
-  /**
-   * Adds a collection of resource entries. Each entry is a string composed of a pair of parts
-   * separated by a colon ':'. The name of the resource comes from the second part, and the path to
-   * the resource comes from the whole string with the colon replaced by a slash '/'.
-   *
-   * <pre>
-   * prefix:name => (name, prefix/name)
-   * </pre>
-   */
-  private static void addResourceEntries(JarCreator jar, Collection<String> resources)
-      throws IOException {
-    for (String resource : resources) {
-      int colon = resource.indexOf(':');
-      if (colon < 0) {
-        throw new IOException("" + resource + ": Illegal resource entry.");
-      }
-      String prefix = resource.substring(0, colon);
-      String name = resource.substring(colon + 1);
-      String path = colon > 0 ? prefix + "/" + name : name;
-      addEntryWithParents(jar, name, path);
-    }
-  }
-
-  private static void addMessageEntries(JarCreator jar, List<String> messages) throws IOException {
-    for (String message : messages) {
-      int colon = message.indexOf(':');
-      if (colon < 0) {
-        throw new IOException("" + message + ": Illegal message entry.");
-      }
-      String prefix = message.substring(0, colon);
-      String name = message.substring(colon + 1);
-      String path = colon > 0 ? prefix + "/" + name : name;
-      File messageFile = new File(path);
-      // Ignore empty messages. They get written by the translation importer
-      // when there is no translation for a particular language.
-      if (messageFile.length() != 0L) {
-        addEntryWithParents(jar, name, path);
-      }
-    }
-  }
-
-  /**
-   * Adds an entry to the jar, making sure that all the parent dirs up to the base of {@code entry}
-   * are also added.
-   *
-   * @param entry the PathFragment of the entry going into the Jar file
-   * @param file the PathFragment of the input file for the entry
-   */
-  @VisibleForTesting
-  static void addEntryWithParents(JarCreator creator, String entry, String file) {
-    while ((entry != null) && creator.addEntry(entry, file)) {
-      entry = new File(entry).getParent();
-      file = new File(file).getParent();
-    }
-  }
-
-  /**
-   * Internal interface which will listen on each entry of the source jar files during the source
-   * jar setup process.
-   */
-  protected interface SourceJarEntryListener {
-    void onEntry(ZipEntry entry) throws IOException;
-
-    void finish() throws IOException;
-  }
-
-  protected List<SourceJarEntryListener> getSourceJarEntryListeners(JavaLibraryBuildRequest build) {
-    List<SourceJarEntryListener> result = new ArrayList<>();
-    result.add(new SourceJavaFileCollector(build));
-    return result;
-  }
-
-  /**
-   * A SourceJarEntryListener that collects a lists of source Java files from the source jar files.
-   */
-  private static class SourceJavaFileCollector implements SourceJarEntryListener {
-    private final List<String> sources;
-    private final JavaLibraryBuildRequest build;
-
-    public SourceJavaFileCollector(JavaLibraryBuildRequest build) {
-      this.sources = new ArrayList<>();
-      this.build = build;
-    }
-
-    @Override
-    public void onEntry(ZipEntry entry) {
-      String entryName = entry.getName();
-      if (entryName.endsWith(".java")) {
-        sources.add(build.getTempDir() + File.separator + entryName);
-      }
-    }
-
-    @Override
-    public void finish() {
-      build.getSourceFiles().addAll(sources);
-    }
-  }
-
-  /**
-   * Extracts the all source jars from the build request into the temporary directory specified in
-   * the build request. Empties the temporary directory, if it exists.
-   */
-  private void setUpSourceJars(JavaLibraryBuildRequest build) throws IOException {
-    String sourcesDir = build.getTempDir();
-
-    File sourceDirFile = new File(sourcesDir);
-    if (sourceDirFile.exists()) {
-      cleanupDirectory(sourceDirFile, true);
-    }
-
-    if (build.getSourceJars().isEmpty()) {
-      return;
-    }
-
-    List<SourceJarEntryListener> listeners = getSourceJarEntryListeners(build);
-    for (String sourceJar : build.getSourceJars()) {
-      setUpSourceJar(new File(sourceJar), sourcesDir, listeners);
-    }
-    for (SourceJarEntryListener listener : listeners) {
-      listener.finish();
-    }
-  }
-
-  /**
-   * Extracts the source jar into the directory sourceDir. Calls each of the SourceJarEntryListeners
-   * for each non-directory entry to do additional work.
-   */
-  private void setUpSourceJar(
-      File sourceJar, String sourceDir, List<SourceJarEntryListener> listeners) throws IOException {
-    try (ZipFile zipFile = new ZipFile(sourceJar)) {
-      Enumeration<? extends ZipEntry> zipEntries = zipFile.entries();
-      while (zipEntries.hasMoreElements()) {
-        ZipEntry currentEntry = zipEntries.nextElement();
-        String entryName = currentEntry.getName();
-        File outputFile = new File(sourceDir, entryName);
-
-        outputFile.getParentFile().mkdirs();
-
-        if (currentEntry.isDirectory()) {
-          outputFile.mkdir();
-        } else {
-          // Copy the data from the zip file to the output file.
-          try (InputStream in = zipFile.getInputStream(currentEntry);
-              OutputStream out = new FileOutputStream(outputFile)) {
-            ByteStreams.copy(in, out);
-          }
-
-          for (SourceJarEntryListener listener : listeners) {
-            listener.onEntry(currentEntry);
-          }
-        }
-      }
-    }
-  }
-
-  /**
-   * Recursively cleans up the files beneath the specified output directory. Does not follow
-   * symbolic links. Throws IOException if any deletion fails.
-   *
-   * <p>Will delete all empty directories.
-   *
-   * @param dir the directory to clean up.
-   * @return true if the directory itself was removed as well.
-   */
-  boolean cleanupOutputDirectory(File dir) throws IOException {
-    return cleanupDirectory(dir, false);
-  }
-
-  /**
-   * Recursively cleans up the files beneath the specified output directory. Does not follow
-   * symbolic links. Throws IOException if any deletion fails. If removeEverything is false, keeps
-   * .class files if keepClassFilesDuringCleanup() returns true. If removeEverything is true,
-   * removes everything. Will delete all empty directories.
-   *
-   * @param dir the directory to clean up.
-   * @param removeEverything whether to remove all files, or keep flags.xml/.class files.
-   * @return true if the directory itself was removed as well.
-   */
-  private boolean cleanupDirectory(File dir, boolean removeEverything) throws IOException {
-    boolean isEmpty = true;
-    File[] files = dir.listFiles();
-    if (files == null) {
-      return false;
-    } // avoid race condition
-    for (File file : files) {
-      if (file.isDirectory()) {
-        isEmpty &= cleanupDirectory(file, removeEverything);
-      } else if (!removeEverything
-          && keepClassFilesDuringCleanup()
-          && file.getName().endsWith(".class")) {
-        isEmpty = false;
-      } else {
-        file.delete();
-      }
-    }
-    if (isEmpty) {
-      dir.delete();
-    }
-    return isEmpty;
-  }
-
-  /**
-   * Returns true if cleaning the output directory should remove all .class files in the output
-   * directory.
-   */
-  protected boolean keepClassFilesDuringCleanup() {
-    return false;
-  }
-}
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
index bf73f62ace..6b9010e3e1 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
@@ -81,7 +81,7 @@ public abstract class BazelJavaBuilder {
   public static int processRequest(List<String> args, PrintWriter err) {
     try {
       JavaLibraryBuildRequest build = parse(args);
-      AbstractJavaBuilder builder =
+      SimpleJavaLibraryBuilder builder =
           build.getDependencyModule().reduceClasspath()
               ? new ReducedClasspathJavaLibraryBuilder()
               : new SimpleJavaLibraryBuilder();
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/SimpleJavaLibraryBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/SimpleJavaLibraryBuilder.java
index 4080cbfbb6..07e2dcb6af 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/SimpleJavaLibraryBuilder.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/SimpleJavaLibraryBuilder.java
@@ -14,26 +14,121 @@
 
 package com.google.devtools.build.buildjar;
 
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.ByteStreams;
+import com.google.common.io.Files;
+import com.google.devtools.build.buildjar.instrumentation.JacocoInstrumentationProcessor;
 import com.google.devtools.build.buildjar.jarhelper.JarCreator;
+import com.google.devtools.build.buildjar.javac.BlazeJavacArguments;
+import com.google.devtools.build.buildjar.javac.BlazeJavacMain;
 import com.google.devtools.build.buildjar.javac.JavacRunner;
+import com.google.devtools.build.buildjar.javac.plugins.BlazeJavaCompilerPlugin;
 import com.sun.tools.javac.main.Main.Result;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
 
 /** An implementation of the JavaBuilder that uses in-process javac to compile java files. */
-public class SimpleJavaLibraryBuilder extends AbstractJavaBuilder {
+public class SimpleJavaLibraryBuilder {
+
+  /** The name of the protobuf meta file. */
+  private static final String PROTOBUF_META_NAME = "protobuf.meta";
+  /** Enables more verbose output from the compiler. */
+  protected boolean debug = false;
+
+  /**
+   * Adds a collection of resource entries. Each entry is a string composed of a pair of parts
+   * separated by a colon ':'. The name of the resource comes from the second part, and the path to
+   * the resource comes from the whole string with the colon replaced by a slash '/'.
+   *
+   * <pre>
+   * prefix:name => (name, prefix/name)
+   * </pre>
+   */
+  private static void addResourceEntries(JarCreator jar, Collection<String> resources)
+      throws IOException {
+    for (String resource : resources) {
+      int colon = resource.indexOf(':');
+      if (colon < 0) {
+        throw new IOException("" + resource + ": Illegal resource entry.");
+      }
+      String prefix = resource.substring(0, colon);
+      String name = resource.substring(colon + 1);
+      String path = colon > 0 ? prefix + "/" + name : name;
+      addEntryWithParents(jar, name, path);
+    }
+  }
+
+  private static void addMessageEntries(JarCreator jar, List<String> messages) throws IOException {
+    for (String message : messages) {
+      int colon = message.indexOf(':');
+      if (colon < 0) {
+        throw new IOException("" + message + ": Illegal message entry.");
+      }
+      String prefix = message.substring(0, colon);
+      String name = message.substring(colon + 1);
+      String path = colon > 0 ? prefix + "/" + name : name;
+      File messageFile = new File(path);
+      // Ignore empty messages. They get written by the translation importer
+      // when there is no translation for a particular language.
+      if (messageFile.length() != 0L) {
+        addEntryWithParents(jar, name, path);
+      }
+    }
+  }
+
+  /**
+   * Adds an entry to the jar, making sure that all the parent dirs up to the base of {@code entry}
+   * are also added.
+   *
+   * @param entry the PathFragment of the entry going into the Jar file
+   * @param file the PathFragment of the input file for the entry
+   */
+  @VisibleForTesting
+  static void addEntryWithParents(JarCreator creator, String entry, String file) {
+    while ((entry != null) && creator.addEntry(entry, file)) {
+      entry = new File(entry).getParent();
+      file = new File(file).getParent();
+    }
+  }
+
+  private static List<SourceJarEntryListener> getSourceJarEntryListeners(
+      JavaLibraryBuildRequest build) {
+    return ImmutableList.of(
+        new SourceJavaFileCollector(build),
+        new ProtoMetaFileCollector(build.getTempDir(), build.getClassDir()));
+  }
 
-  @Override
   Result compileSources(JavaLibraryBuildRequest build, JavacRunner javacRunner, PrintWriter err)
       throws IOException {
     return javacRunner.invokeJavac(
         build.getPlugins(), build.toBlazeJavacArguments(build.getClassPath()), err);
   }
 
-  @Override
   protected void prepareSourceCompilation(JavaLibraryBuildRequest build) throws IOException {
-    super.prepareSourceCompilation(build);
+    File classDirectory = new File(build.getClassDir());
+    if (classDirectory.exists()) {
+      try {
+        // Necessary for local builds in order to discard previous outputs
+        cleanupOutputDirectory(classDirectory);
+      } catch (IOException e) {
+        throw new IOException("Cannot clean output directory '" + classDirectory + "'", e);
+      }
+    }
+    classDirectory.mkdirs();
+
+    setUpSourceJars(build);
 
     // Create sourceGenDir if necessary.
     if (build.getSourceGenDir() != null) {
@@ -49,7 +144,6 @@ public class SimpleJavaLibraryBuilder extends AbstractJavaBuilder {
     }
   }
 
-  @Override
   public void buildGensrcJar(JavaLibraryBuildRequest build) throws IOException {
     JarCreator jar = new JarCreator(build.getGeneratedSourcesOutputJar());
     jar.setNormalize(true);
@@ -57,4 +151,263 @@ public class SimpleJavaLibraryBuilder extends AbstractJavaBuilder {
     jar.addDirectory(build.getSourceGenDir());
     jar.execute();
   }
+
+  /**
+   * Prepares a compilation run and sets everything up so that the source files in the build request
+   * can be compiled. Invokes compileSources to do the actual compilation.
+   *
+   * @param build A JavaLibraryBuildRequest request object describing what to compile
+   * @param err PrintWriter for logging any diagnostic output
+   */
+  public Result compileJavaLibrary(final JavaLibraryBuildRequest build, final PrintWriter err)
+      throws Exception {
+    prepareSourceCompilation(build);
+    if (build.getSourceFiles().isEmpty()) {
+      return Result.OK;
+    }
+    JavacRunner javacRunner =
+        new JavacRunner() {
+          @Override
+          public Result invokeJavac(
+              ImmutableList<BlazeJavaCompilerPlugin> plugins,
+              BlazeJavacArguments arguments,
+              PrintWriter output) {
+            return new BlazeJavacMain(output, plugins).compile(arguments);
+          }
+        };
+    Result result = compileSources(build, javacRunner, err);
+    JacocoInstrumentationProcessor processor = build.getJacocoInstrumentationProcessor();
+    if (processor != null) {
+      processor.processRequest(build);
+    }
+    return result;
+  }
+
+  /** Perform the build. */
+  public Result run(JavaLibraryBuildRequest build, PrintWriter err) throws Exception {
+    Result result = Result.ERROR;
+    try {
+      result = compileJavaLibrary(build, err);
+      if (result.isOK()) {
+        buildJar(build);
+      }
+      if (!build.getProcessors().isEmpty()) {
+        if (build.getGeneratedSourcesOutputJar() != null) {
+          buildGensrcJar(build);
+        }
+      }
+    } finally {
+      build.getDependencyModule().emitDependencyInformation(build.getClassPath(), result.isOK());
+      build.getProcessingModule().emitManifestProto();
+    }
+    return result;
+  }
+
+  public void buildJar(JavaLibraryBuildRequest build) throws IOException {
+    JarCreator jar = new JarCreator(build.getOutputJar());
+    jar.setNormalize(true);
+    jar.setCompression(build.compressJar());
+
+    // The easiest way to handle resource jars is to unpack them into the class directory, just
+    // before we start zipping it up.
+    for (String resourceJar : build.getResourceJars()) {
+      setUpSourceJar(
+          new File(resourceJar), build.getClassDir(), new ArrayList<SourceJarEntryListener>());
+    }
+
+    jar.addDirectory(build.getClassDir());
+
+    jar.addRootEntries(build.getRootResourceFiles());
+    SimpleJavaLibraryBuilder.addResourceEntries(jar, build.getResourceFiles());
+    SimpleJavaLibraryBuilder.addMessageEntries(jar, build.getMessageFiles());
+
+    jar.execute();
+  }
+
+  /**
+   * Extracts the all source jars from the build request into the temporary directory specified in
+   * the build request. Empties the temporary directory, if it exists.
+   */
+  private void setUpSourceJars(JavaLibraryBuildRequest build) throws IOException {
+    String sourcesDir = build.getTempDir();
+
+    File sourceDirFile = new File(sourcesDir);
+    if (sourceDirFile.exists()) {
+      cleanupDirectory(sourceDirFile, true);
+    }
+
+    if (build.getSourceJars().isEmpty()) {
+      return;
+    }
+
+    List<SourceJarEntryListener> listeners = getSourceJarEntryListeners(build);
+    for (String sourceJar : build.getSourceJars()) {
+      setUpSourceJar(new File(sourceJar), sourcesDir, listeners);
+    }
+    for (SourceJarEntryListener listener : listeners) {
+      listener.finish();
+    }
+  }
+
+  /**
+   * Extracts the source jar into the directory sourceDir. Calls each of the SourceJarEntryListeners
+   * for each non-directory entry to do additional work.
+   */
+  private void setUpSourceJar(
+      File sourceJar, String sourceDir, List<SourceJarEntryListener> listeners) throws IOException {
+    try (ZipFile zipFile = new ZipFile(sourceJar)) {
+      Enumeration<? extends ZipEntry> zipEntries = zipFile.entries();
+      while (zipEntries.hasMoreElements()) {
+        ZipEntry currentEntry = zipEntries.nextElement();
+        String entryName = currentEntry.getName();
+        File outputFile = new File(sourceDir, entryName);
+
+        outputFile.getParentFile().mkdirs();
+
+        if (currentEntry.isDirectory()) {
+          outputFile.mkdir();
+        } else {
+          // Copy the data from the zip file to the output file.
+          try (InputStream in = zipFile.getInputStream(currentEntry);
+              OutputStream out = new FileOutputStream(outputFile)) {
+            ByteStreams.copy(in, out);
+          }
+
+          for (SourceJarEntryListener listener : listeners) {
+            listener.onEntry(currentEntry);
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Recursively cleans up the files beneath the specified output directory. Does not follow
+   * symbolic links. Throws IOException if any deletion fails.
+   *
+   * <p>Will delete all empty directories.
+   *
+   * @param dir the directory to clean up.
+   * @return true if the directory itself was removed as well.
+   */
+  boolean cleanupOutputDirectory(File dir) throws IOException {
+    return cleanupDirectory(dir, false);
+  }
+
+  /**
+   * Recursively cleans up the files beneath the specified output directory. Does not follow
+   * symbolic links. Throws IOException if any deletion fails. If removeEverything is false, keeps
+   * .class files if keepClassFilesDuringCleanup() returns true. If removeEverything is true,
+   * removes everything. Will delete all empty directories.
+   *
+   * @param dir the directory to clean up.
+   * @param removeEverything whether to remove all files, or keep flags.xml/.class files.
+   * @return true if the directory itself was removed as well.
+   */
+  private boolean cleanupDirectory(File dir, boolean removeEverything) throws IOException {
+    boolean isEmpty = true;
+    File[] files = dir.listFiles();
+    if (files == null) {
+      return false;
+    } // avoid race condition
+    for (File file : files) {
+      if (file.isDirectory()) {
+        isEmpty &= cleanupDirectory(file, removeEverything);
+      } else if (!removeEverything
+          && keepClassFilesDuringCleanup()
+          && file.getName().endsWith(".class")) {
+        isEmpty = false;
+      } else {
+        file.delete();
+      }
+    }
+    if (isEmpty) {
+      dir.delete();
+    }
+    return isEmpty;
+  }
+
+  /**
+   * Returns true if cleaning the output directory should remove all .class files in the output
+   * directory.
+   */
+  protected boolean keepClassFilesDuringCleanup() {
+    return false;
+  }
+
+  /**
+   * Internal interface which will listen on each entry of the source jar files during the source
+   * jar setup process.
+   */
+  protected interface SourceJarEntryListener {
+    void onEntry(ZipEntry entry) throws IOException;
+
+    void finish() throws IOException;
+  }
+
+  /** A SourceJarEntryListener that collects protobuf meta data files from the source jar files. */
+  private static class ProtoMetaFileCollector implements SourceJarEntryListener {
+
+    private final String sourceDir;
+    private final String outputDir;
+    private final ByteArrayOutputStream buffer;
+
+    public ProtoMetaFileCollector(String sourceDir, String outputDir) {
+      this.sourceDir = sourceDir;
+      this.outputDir = outputDir;
+      this.buffer = new ByteArrayOutputStream();
+    }
+
+    @Override
+    public void onEntry(ZipEntry entry) throws IOException {
+      String entryName = entry.getName();
+      if (!entryName.equals(PROTOBUF_META_NAME)) {
+        return;
+      }
+      Files.copy(new File(sourceDir, PROTOBUF_META_NAME), buffer);
+    }
+
+    /**
+     * Writes the combined the meta files into the output directory. Delete the stalling meta file
+     * if no meta file is collected.
+     */
+    @Override
+    public void finish() throws IOException {
+      File outputFile = new File(outputDir, PROTOBUF_META_NAME);
+      if (buffer.size() > 0) {
+        try (OutputStream outputStream = new FileOutputStream(outputFile)) {
+          buffer.writeTo(outputStream);
+        }
+      } else if (outputFile.exists()) {
+        // Delete stalled meta file.
+        outputFile.delete();
+      }
+    }
+  }
+
+  /**
+   * A SourceJarEntryListener that collects a lists of source Java files from the source jar files.
+   */
+  private static class SourceJavaFileCollector implements SourceJarEntryListener {
+    private final List<String> sources;
+    private final JavaLibraryBuildRequest build;
+
+    public SourceJavaFileCollector(JavaLibraryBuildRequest build) {
+      this.sources = new ArrayList<>();
+      this.build = build;
+    }
+
+    @Override
+    public void onEntry(ZipEntry entry) {
+      String entryName = entry.getName();
+      if (entryName.endsWith(".java")) {
+        sources.add(build.getTempDir() + File.separator + entryName);
+      }
+    }
+
+    @Override
+    public void finish() {
+      build.getSourceFiles().addAll(sources);
+    }
+  }
 }