Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.runtime.local;
020
021import org.apache.reef.runtime.common.files.RuntimeClasspathProvider;
022import org.apache.reef.util.Optional;
023
024import javax.inject.Inject;
025import java.io.File;
026import java.nio.file.Path;
027import java.util.ArrayList;
028import java.util.Collections;
029import java.util.LinkedHashSet;
030import java.util.List;
031
032/**
033 * RuntimeClasspathProvider for the local runtime.
034 * <p>
035 * The prefix for the local runtime is empty, the suffix is the classpath of the current JVM. That classpath is filtered
036 * to not contain subfolders of JAVA_HOME. Also, duplicates are removed.
037 */
038public final class LocalClasspathProvider implements RuntimeClasspathProvider {
039  private final List<String> classPathSuffix;
040
041  @Inject
042  LocalClasspathProvider() {
043    this.classPathSuffix = Collections.unmodifiableList(new ArrayList<>(getFilteredClasspath()));
044  }
045
046  /**
047   * @return the classpath filtered by entries in subfolders of JAVA_HOME are removed, so are duplicate entries.
048   */
049  private static LinkedHashSet<String> getFilteredClasspath() {
050    final LinkedHashSet<String> result = new LinkedHashSet<>();
051    final Optional<Path> javaHome = getJavaHome();
052
053    if (javaHome.isPresent()) {
054      final Path javaHomePath = javaHome.get();
055      for (final Path classPathEntry : getClasspath()) {
056        if (!classPathEntry.startsWith(javaHomePath)) {
057          result.add(toAbsolutePathString(classPathEntry));
058        }
059      }
060    } else {
061      for (final Path classPathEntry : getClasspath()) {
062        result.add(toAbsolutePathString(classPathEntry));
063      }
064    }
065    return result;
066  }
067
068  /**
069   * @return the path to "JAVA_HOME", if that is set. Optional.empty(), else.
070   */
071  private static Optional<Path> getJavaHome() {
072    final Optional<String> javaHome = getEnv("JAVA_HOME");
073
074    if (javaHome.isPresent()) {
075      final File javaHomeFile = new File(javaHome.get());
076      if (javaHomeFile.exists()) {
077        return Optional.of(javaHomeFile.toPath());
078      }
079    }
080    return Optional.empty();
081  }
082
083  /**
084   * @param envName
085   * @return the value of the environment variable, if there is one.
086   */
087  private static Optional<String> getEnv(final String envName) {
088    return Optional.ofNullable(System.getenv(envName));
089  }
090
091  /**
092   * @return the classpath of the current JVM. Duplicates are removed.
093   */
094  private static LinkedHashSet<Path> getClasspath() {
095    final LinkedHashSet<Path> result = new LinkedHashSet<>();
096    for (final String classPathEntry : System.getProperty("java.class.path").split(File.pathSeparator)) {
097      final File file = new File(classPathEntry);
098      if (file.exists()) {
099        result.add(file.toPath());
100      }
101    }
102    return result;
103  }
104
105  /**
106   * Concerts the given path into a String representing the absolute path.
107   *
108   * @param path
109   * @return
110   */
111  private static String toAbsolutePathString(final Path path) {
112    return path.toAbsolutePath().toString();
113  }
114
115  @Override
116  public List<String> getDriverClasspathPrefix() {
117    return Collections.emptyList();
118  }
119
120  @Override
121  public List<String> getDriverClasspathSuffix() {
122    return this.classPathSuffix;
123  }
124
125  @Override
126  public List<String> getEvaluatorClasspathPrefix() {
127    return Collections.emptyList();
128  }
129
130  @Override
131  public List<String> getEvaluatorClasspathSuffix() {
132    return this.classPathSuffix;
133  }
134}