com.google.caliper.runner.target.EffectiveClassPath.java Source code

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Here is the source code for com.google.caliper.runner.target.EffectiveClassPath.java

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/*
 * Copyright (C) 2013 Google Inc.
 *
 * 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.caliper.runner.target;

import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableSet;
import java.io.File;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.LinkedHashSet;
import java.util.Set;
import javax.annotation.Nullable;

/**
 * Provides a class path containing all of the jars present on the local machine that are referenced
 * by a given {@link ClassLoader}.
 */
final class EffectiveClassPath {
    private EffectiveClassPath() {
    }

    private static final String PATH_SEPARATOR = System.getProperty("path.separator");
    private static final String JAVA_CLASS_PATH = System.getProperty("java.class.path");

    static String getClassPathForClassLoader(ClassLoader classLoader) {
        // Order of JAR files may have some significance. Try to preserve it.
        LinkedHashSet<File> files = new LinkedHashSet<File>();
        for (String entry : Splitter.on(PATH_SEPARATOR).split(JAVA_CLASS_PATH)) {
            files.add(new File(entry));
        }
        files.addAll(getClassPathFiles(classLoader));

        return Joiner.on(PATH_SEPARATOR).join(files);
    }

    private static Set<File> getClassPathFiles(ClassLoader classLoader) {
        ImmutableSet.Builder<File> files = ImmutableSet.builder();
        @Nullable
        ClassLoader parent = classLoader.getParent();
        if (parent != null) {
            files.addAll(getClassPathFiles(parent));
        }
        if (classLoader instanceof URLClassLoader) {
            URLClassLoader urlClassLoader = (URLClassLoader) classLoader;
            for (URL url : urlClassLoader.getURLs()) {
                try {
                    files.add(new File(url.toURI()));
                } catch (URISyntaxException e) {
                    // skip it then
                } catch (IllegalArgumentException e) {
                    // skip it then
                }
            }
        }
        return files.build();
    }
}