Prepare Classpath reading for Java 9

PiperOrigin-RevId: 171180273
fulldecent · Oct 6, 2017 · e9cc512 · e9cc512
1 parent 06d2410
commit e9cc512
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Showing 2 changed files with 16 additions and 140 deletions.
diff --git a/src/main/java/com/google/devtools/build/lib/BUILD b/src/main/java/com/google/devtools/build/lib/BUILD
@@ -135,7 +135,10 @@ java_library(
 java_library(
     name = "classpath-util",
     srcs = ["util/Classpath.java"],
-    deps = ["//src/main/java/com/google/devtools/build/lib:preconditions"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib:preconditions",
+        "//third_party:guava",
+    ],
 )
 
 java_library(

diff --git a/src/main/java/com/google/devtools/build/lib/util/Classpath.java b/src/main/java/com/google/devtools/build/lib/util/Classpath.java
@@ -13,29 +13,17 @@
 // limitations under the License.
 package com.google.devtools.build.lib.util;
 
-import java.io.File;
+import com.google.common.reflect.ClassPath;
+import com.google.common.reflect.ClassPath.ClassInfo;
 import java.io.IOException;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.net.URL;
-import java.net.URLClassLoader;
-import java.nio.file.Paths;
-import java.util.Enumeration;
 import java.util.LinkedHashSet;
 import java.util.Set;
-import java.util.TreeSet;
-import java.util.jar.Attributes;
-import java.util.jar.JarFile;
-import java.util.jar.Manifest;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
 
 /**
  * A helper class to find all classes on the current classpath. This is used to automatically create
  * JUnit 3 and 4 test suites.
  */
 public final class Classpath {
-  private static final String CLASS_EXTENSION = ".class";
 
   /**
    * Base exception for any classpath related errors.
@@ -49,135 +37,20 @@ public ClassPathException(String format, Object... args) {
   /** Finds all classes that live in or below the given package. */
   public static Set<Class<?>> findClasses(String packageName) throws ClassPathException {
     Set<Class<?>> result = new LinkedHashSet<>();
-    String pathPrefix = (packageName + '.').replace('.', '/');
-    for (String entryName : getClassPath()) {
-      File classPathEntry = new File(entryName);
-      if (classPathEntry.exists()) {
-        try {
-          Set<String> classNames;
-          if (classPathEntry.isDirectory()) {
-            classNames = findClassesInDirectory(classPathEntry, pathPrefix);
-          } else {
-            classNames = findClassesInJar(classPathEntry, pathPrefix);
-          }
-          for (String className : classNames) {
-            try {
-              Class<?> clazz = Class.forName(className);
-              result.add(clazz);
-            } catch (UnsatisfiedLinkError | NoClassDefFoundError unused) {
-              // Ignore: we're most likely running on a different platform.
-            }
-          }
-        } catch (IOException e) {
-          throw new ClassPathException(
-              "Can't read classpath entry %s: %s", entryName, e.getMessage());
-        } catch (ClassNotFoundException e) {
-          throw new ClassPathException(
-              "Class not found even though it is on the classpath %s: %s",
-              entryName, e.getMessage());
-        }
-      }
-    }
-    return result;
-  }
-
-  private static Set<String> findClassesInDirectory(File classPathEntry, String pathPrefix) {
-    Set<String> result = new TreeSet<>();
-    File directory = new File(classPathEntry, pathPrefix);
-    innerFindClassesInDirectory(result, directory, pathPrefix);
-    return result;
-  }
-
-  /**
-   * Finds all classes and sub packages in the given directory that are below the given package and
-   * add them to the respective sets.
-   *
-   * @param directory Directory to inspect
-   * @param pathPrefix Prefix for the path to the classes that are requested
-   *                   (ex: {@code com/google/foo/bar})
-   */
-  private static void innerFindClassesInDirectory(Set<String> classNames, File directory,
-      String pathPrefix) {
-    Preconditions.checkArgument(pathPrefix.endsWith("/"));
-    if (directory.exists()) {
-      for (File f : directory.listFiles()) {
-        String name = f.getName();
-        if (name.endsWith(CLASS_EXTENSION)) {
-          String clzName = getClassName(pathPrefix + name);
-          classNames.add(clzName);
-        } else if (f.isDirectory()) {
-          findClassesInDirectory(f, pathPrefix + name + "/");
-        }
-      }
-    }
-  }
-
-  /**
-   * Returns a set of all classes in the jar that start with the given prefix.
-   */
-  private static Set<String> findClassesInJar(File jarFile, String pathPrefix) throws IOException {
-    Set<String> classNames = new TreeSet<>();
-    try (ZipFile zipFile = new ZipFile(jarFile)) {
-      Enumeration<? extends ZipEntry> entries = zipFile.entries();
-      while (entries.hasMoreElements()) {
-        String entryName = entries.nextElement().getName();
-        if (entryName.startsWith(pathPrefix) && entryName.endsWith(CLASS_EXTENSION)) {
-          classNames.add(getClassName(entryName));
-        }
-      }
-    }
-    return classNames;
-  }
-
-  /**
-   * Given the absolute path of a class file, return the class name.
-   */
-  private static String getClassName(String className) {
-    int classNameEnd = className.length() - CLASS_EXTENSION.length();
-    return className.substring(0, classNameEnd).replace('/', '.');
-  }
-
-  private static void getClassPathsFromClasspathJar(File classpathJar, Set<String> classPaths)
-      throws IOException, ClassPathException {
-    Manifest manifest = new JarFile(classpathJar).getManifest();
-    Attributes attributes = manifest.getMainAttributes();
-    for (String classPath : attributes.getValue("Class-Path").split(" ")) {
-      try {
-        classPaths.add(Paths.get(new URI(classPath)).toAbsolutePath().toString());
-      } catch (URISyntaxException e) {
-        throw new ClassPathException(
-            "Error parsing classpath uri %s: %s", classPath, e.getMessage());
-      }
-    }
-  }
-
-  /** Gets the classpath from current classloader. */
-  private static Set<String> getClassPath() throws ClassPathException {
-    ClassLoader classloader = Classpath.class.getClassLoader();
-    if (!(classloader instanceof URLClassLoader)) {
-      throw new IllegalStateException("Unable to find classes to test, since Test Suite class is "
-          + "loaded by an unsupported Classloader.");
-    }
-
-    Set<String> completeClassPaths = new TreeSet<>();
-    URL[] urls = ((URLClassLoader) classloader).getURLs();
-    for (URL url : urls) {
-      String entryName = url.getPath();
-      completeClassPaths.add(entryName);
-      if (entryName.endsWith("-classpath.jar")) {
-        // Bazel creates a classpath jar when the class path length exceeds command line length
-        // limit, read the class path value from its manifest file if it's a classpath jar.
-        File classPathEntry = new File(entryName);
-        if (classPathEntry.exists() && classPathEntry.isFile()) {
+    String packagePrefix = (packageName + '.').replace('/', '.');
+    try {
+      for (ClassInfo ci : ClassPath.from(Classpath.class.getClassLoader()).getAllClasses()) {
+        if (ci.getName().startsWith(packagePrefix)) {
           try {
-            getClassPathsFromClasspathJar(classPathEntry, completeClassPaths);
-          } catch (IOException e) {
-            throw new ClassPathException(
-                "Can't read classpath entry %s: %s", entryName, e.getMessage());
+            result.add(ci.load());
+          } catch (UnsatisfiedLinkError | NoClassDefFoundError unused) {
+            // Ignore: we're most likely running on a different platform.
           }
         }
       }
+    } catch (IOException e) {
+      throw new ClassPathException(e.getMessage());
     }
-    return completeClassPaths;
+    return result;
   }
 }