Contents

/*
 * Copyright 2017 CyberAgent, 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 org.embulk.input.parquet_hadoop;

/**
 * Set the context class loader to plugin's class loader.
 *
 * {@link org.apache.hadoop.fs.FileSystem#loadFileSystems()} loads FileSystem implementation via
 * {@link java.util.ServiceLoader}.
 * It's look up services via system class loader if context class loader is null.
 * However system class loader failed to look up FileSystem implementations because
 * hadoop jars is not in classpath of system class loader.
 * So we need to set context class loader to plugins' class loader.
 */
class PluginClassLoaderScope implements AutoCloseable
{
    private static final ClassLoader PLUGIN_CLASS_LOADER =
            ParquetHadoopInputPlugin.class.getClassLoader();

    private final ClassLoader original;

    public PluginClassLoaderScope()
    {
        Thread current = Thread.currentThread();
        this.original = current.getContextClassLoader();
        Thread.currentThread().setContextClassLoader(PLUGIN_CLASS_LOADER);
    }

    @Override
    public void close()
    {
        Thread.currentThread().setContextClassLoader(original);
    }
}

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
embulk-input-parquet_hadoop-0.1.1	src/main/java/org/embulk/input/parquet_hadoop/PluginClassLoaderScope.java