co.cask.cdap.security.authorization.AuthorizerClassLoader.java Source code

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Here is the source code for co.cask.cdap.security.authorization.AuthorizerClassLoader.java

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/*
 * Copyright  2016 Cask Data, 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 co.cask.cdap.security.authorization;

import co.cask.cdap.api.app.Application;
import co.cask.cdap.common.lang.ClassPathResources;
import co.cask.cdap.common.lang.DirectoryClassLoader;
import co.cask.cdap.common.lang.FilterClassLoader;
import co.cask.cdap.security.spi.authorization.Authorizer;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.util.Set;

/**
 * {@link DirectoryClassLoader} for {@link Authorizer} extensions.
 */
public class AuthorizerClassLoader extends DirectoryClassLoader {

    private static final Logger LOG = LoggerFactory.getLogger(AuthorizerClassLoader.class);

    @VisibleForTesting
    static ClassLoader createParent() {
        ClassLoader baseClassLoader = AuthorizerClassLoader.class.getClassLoader();
        // Trace dependencies for Authorizer class. This will make classes from cdap-security-spi as well as  cdap-proto
        // and other dependencies of cdap-security-spi available to the authorizer extension.
        Set<String> authorizerResources;
        try {
            authorizerResources = ClassPathResources.getResourcesWithDependencies(baseClassLoader,
                    Authorizer.class);
        } catch (IOException e) {
            LOG.error("Failed to determine resources for authorizer class loader while tracing dependencies of "
                    + "Authorizer.", e);
            authorizerResources = ImmutableSet.of();
        }

        // Trace dependencies of cdap-api and include them as well. This will make classes like slf4j Logger implementation
        // as well as classes from twill-api and other dependencies required for cdap-api available to the authorizer
        // extension.
        Set<String> apiResources;
        try {
            apiResources = ClassPathResources.getResourcesWithDependencies(baseClassLoader, Application.class);
        } catch (IOException e) {
            LOG.error("Failed to determine resources for authorizer class loader while tracing dependencies of "
                    + "cdap-api.", e);
            apiResources = ImmutableSet.of();
        }
        final Set<String> finalAuthorizerResources = Sets.union(authorizerResources, apiResources);
        return new FilterClassLoader(baseClassLoader, new FilterClassLoader.Filter() {
            @Override
            public boolean acceptResource(String resource) {
                return finalAuthorizerResources.contains(resource);
            }

            @Override
            public boolean acceptPackage(String packageName) {
                return true;
            }
        });
    }

    AuthorizerClassLoader(File unpackedJarDir) {
        super(unpackedJarDir, createParent(), "lib");
    }
}