minifi-nar-bundles/minifi-framework-bundle/minifi-framework/minifi-nar-utils/src/main/java/org/apache/nifi/nar/NarClassLoader.java - nifi-minifi - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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.apache.nifi.nar;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.io.File;
 import java.io.FileFilter;
 import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;

 /**
  * <p>
  * A <tt>ClassLoader</tt> for loading NARs (NiFi archives). NARs are designed to
  * allow isolating bundles of code (comprising one-or-more NiFi
  * <tt>FlowFileProcessor</tt>s, <tt>FlowFileComparator</tt>s and their
  * dependencies) from other such bundles; this allows for dependencies and
  * processors that require conflicting, incompatible versions of the same
  * dependency to run in a single instance of NiFi.</p>
  *
  * <p>
  * <tt>NarClassLoader</tt> follows the delegation model described in
  * {@link ClassLoader#findClass(String) ClassLoader.findClass(...)};
  * classes are first loaded from the parent <tt>ClassLoader</tt>, and only if
  * they cannot be found there does the <tt>NarClassLoader</tt> provide a
  * definition. Specifically, this means that resources are loaded from NiFi's
  * <tt>conf</tt>
  * and <tt>lib</tt> directories first, and if they cannot be found there, are
  * loaded from the NAR.</p>
  *
  * <p>
  * The packaging of a NAR is such that it is a ZIP file with the following
  * directory structure:
  *
  * <pre>
  *   +META-INF/
  *   +-- bundled-dependencies/
  *   +-- &lt;JAR files&gt;
  *   +-- MANIFEST.MF
  * </pre>
  * </p>
  *
  * <p>
  * The MANIFEST.MF file contains the same information as a typical JAR file but
  * also includes two additional NiFi properties: {@code Nar-Id} and
  * {@code Nar-Dependency-Id}.
  * </p>
  *
  * <p>
  * The {@code Nar-Id} provides a unique identifier for this NAR.
  * </p>
  *
  * <p>
  * The {@code Nar-Dependency-Id} is optional. If provided, it indicates that
  * this NAR should inherit all of the dependencies of the NAR with the provided
  * ID. Often times, the NAR that is depended upon is referred to as the Parent.
  * This is because its ClassLoader will be the parent ClassLoader of the
  * dependent NAR.
  * </p>
  *
  * <p>
  * If a NAR is built using NiFi's Maven NAR Plugin, the {@code Nar-Id} property
  * will be set to the artifactId of the NAR. The {@code Nar-Dependency-Id} will
  * be set to the artifactId of the NAR that is depended upon. For example, if
  * NAR A is defined as such:
  *
  * <pre>
  * ...
  * &lt;artifactId&gt;nar-a&lt;/artifactId&gt;
  * &lt;packaging&gt;nar&lt;/packaging&gt;
  * ...
  * &lt;dependencies&gt;
  *   &lt;dependency&gt;
  *     &lt;groupId&gt;group&lt;/groupId&gt;
  *     &lt;artifactId&gt;nar-z&lt;/artifactId&gt;
  *     <b>&lt;type&gt;nar&lt;/type&gt;</b>
  *   &lt;/dependency&gt;
  * &lt;/dependencies&gt;
  * </pre>
  * </p>
  *
  *
  * <p>
  * Then the MANIFEST.MF file that is created for NAR A will have the following
  * properties set:
  * <ul>
  * <li>{@code Nar-Id: nar-a}</li>
  * <li>{@code Nar-Dependency-Id: nar-z}</li>
  * </ul>
  * </p>
  *
  * <p>
  * Note, above, that the {@code type} of the dependency is set to {@code nar}.
  * </p>
  *
  * <p>
  * If the NAR has more than one dependency of {@code type} {@code nar}, then the
  * Maven NAR plugin will fail to build the NAR.
  * </p>
  */
 public class NarClassLoader extends URLClassLoader {

     private static final Logger LOGGER = LoggerFactory.getLogger(NarClassLoader.class);

     private static final FileFilter JAR_FILTER = new FileFilter() {
         @Override
         public boolean accept(File pathname) {
             final String nameToTest = pathname.getName().toLowerCase();
             return nameToTest.endsWith(".jar") && pathname.isFile();
         }
     };

     /**
      * The NAR for which this <tt>ClassLoader</tt> is responsible.
      */
     private final File narWorkingDirectory;

     /**
      * Construct a nar class loader.
      *
      * @param narWorkingDirectory directory to explode nar contents to
      * @throws IllegalArgumentException if the NAR is missing the Java Services
      * API file for <tt>FlowFileProcessor</tt> implementations.
      * @throws ClassNotFoundException if any of the <tt>FlowFileProcessor</tt>
      * implementations defined by the Java Services API cannot be loaded.
      * @throws IOException if an error occurs while loading the NAR.
      */
     public NarClassLoader(final File narWorkingDirectory) throws ClassNotFoundException, IOException {
         super(new URL[0]);
         this.narWorkingDirectory = narWorkingDirectory;

         // process the classpath
         updateClasspath(narWorkingDirectory);
     }

     /**
      * Construct a nar class loader with the specific parent.
      *
      * @param narWorkingDirectory directory to explode nar contents to
      * @param parentClassLoader parent class loader of this nar
      * @throws IllegalArgumentException if the NAR is missing the Java Services
      * API file for <tt>FlowFileProcessor</tt> implementations.
      * @throws ClassNotFoundException if any of the <tt>FlowFileProcessor</tt>
      * implementations defined by the Java Services API cannot be loaded.
      * @throws IOException if an error occurs while loading the NAR.
      */
     public NarClassLoader(final File narWorkingDirectory, final ClassLoader parentClassLoader) throws ClassNotFoundException, IOException {
         super(new URL[0], parentClassLoader);
         this.narWorkingDirectory = narWorkingDirectory;

         // process the classpath
         updateClasspath(narWorkingDirectory);
     }

     public File getWorkingDirectory() {
         return narWorkingDirectory;
     }

     /**
      * Adds URLs for the resources unpacked from this NAR:
      * <ul><li>the root: for classes, <tt>META-INF</tt>, etc.</li>
      * <li><tt>META-INF/dependencies</tt>: for config files, <tt>.so</tt>s,
      * etc.</li>
      * <li><tt>META-INF/dependencies/*.jar</tt>: for dependent
      * libraries</li></ul>
      *
      * @param root the root directory of the unpacked NAR.
      * @throws IOException if the URL list could not be updated.
      */
     private void updateClasspath(File root) throws IOException {
         addURL(root.toURI().toURL()); // for compiled classes, META-INF/, etc.

         File dependencies = new File(root, "META-INF/bundled-dependencies");
         if (!dependencies.isDirectory()) {
             LOGGER.warn(narWorkingDirectory + " does not contain META-INF/bundled-dependencies!");
         }
         addURL(dependencies.toURI().toURL());
         if (dependencies.isDirectory()) {
             for (File libJar : dependencies.listFiles(JAR_FILTER)) {
                 addURL(libJar.toURI().toURL());
             }
         }
     }

     @Override
     protected String findLibrary(final String libname) {
         File dependencies = new File(narWorkingDirectory, "META-INF/bundled-dependencies");
         if (!dependencies.isDirectory()) {
             LOGGER.warn(narWorkingDirectory + " does not contain META-INF/bundled-dependencies!");
         }

         final File nativeDir = new File(dependencies, "native");
         final File libsoFile = new File(nativeDir, "lib" + libname + ".so");
         final File dllFile = new File(nativeDir, libname + ".dll");
         final File soFile = new File(nativeDir, libname + ".so");
         if (libsoFile.exists()) {
             return libsoFile.getAbsolutePath();
         } else if (dllFile.exists()) {
             return dllFile.getAbsolutePath();
         } else if (soFile.exists()) {
             return soFile.getAbsolutePath();
         }

         // not found in the nar. try system native dir
         return null;
     }

     @Override
     public String toString() {
         return NarClassLoader.class.getName() + "[" + narWorkingDirectory.getPath() + "]";
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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.apache.nifi.nar;

	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import java.io.File;
	import java.io.FileFilter;
	import java.io.IOException;
	import java.net.URL;
	import java.net.URLClassLoader;

	/**
	* <p>
	* A <tt>ClassLoader</tt> for loading NARs (NiFi archives). NARs are designed to
	* allow isolating bundles of code (comprising one-or-more NiFi
	* <tt>FlowFileProcessor</tt>s, <tt>FlowFileComparator</tt>s and their
	* dependencies) from other such bundles; this allows for dependencies and
	* processors that require conflicting, incompatible versions of the same
	* dependency to run in a single instance of NiFi.</p>
	*
	* <p>
	* <tt>NarClassLoader</tt> follows the delegation model described in
	* {@link ClassLoader#findClass(String) ClassLoader.findClass(...)};
	* classes are first loaded from the parent <tt>ClassLoader</tt>, and only if
	* they cannot be found there does the <tt>NarClassLoader</tt> provide a
	* definition. Specifically, this means that resources are loaded from NiFi's
	* <tt>conf</tt>
	* and <tt>lib</tt> directories first, and if they cannot be found there, are
	* loaded from the NAR.</p>
	*
	* <p>
	* The packaging of a NAR is such that it is a ZIP file with the following
	* directory structure:
	*
	* <pre>
	* +META-INF/
	* +-- bundled-dependencies/
	* +-- <JAR files>
	* +-- MANIFEST.MF
	* </pre>
	* </p>
	*
	* <p>
	* The MANIFEST.MF file contains the same information as a typical JAR file but
	* also includes two additional NiFi properties: {@code Nar-Id} and
	* {@code Nar-Dependency-Id}.
	* </p>
	*
	* <p>
	* The {@code Nar-Id} provides a unique identifier for this NAR.
	* </p>
	*
	* <p>
	* The {@code Nar-Dependency-Id} is optional. If provided, it indicates that
	* this NAR should inherit all of the dependencies of the NAR with the provided
	* ID. Often times, the NAR that is depended upon is referred to as the Parent.
	* This is because its ClassLoader will be the parent ClassLoader of the
	* dependent NAR.
	* </p>
	*
	* <p>
	* If a NAR is built using NiFi's Maven NAR Plugin, the {@code Nar-Id} property
	* will be set to the artifactId of the NAR. The {@code Nar-Dependency-Id} will
	* be set to the artifactId of the NAR that is depended upon. For example, if
	* NAR A is defined as such:
	*
	* <pre>
	* ...
	* <artifactId>nar-a</artifactId>
	* <packaging>nar</packaging>
	* ...
	* <dependencies>
	* <dependency>
	* <groupId>group</groupId>
	* <artifactId>nar-z</artifactId>
	* <b><type>nar</type></b>
	* </dependency>
	* </dependencies>
	* </pre>
	* </p>
	*
	*
	* <p>
	* Then the MANIFEST.MF file that is created for NAR A will have the following
	* properties set:
	* <ul>
	* <li>{@code Nar-Id: nar-a}</li>
	* <li>{@code Nar-Dependency-Id: nar-z}</li>
	* </ul>
	* </p>
	*
	* <p>
	* Note, above, that the {@code type} of the dependency is set to {@code nar}.
	* </p>
	*
	* <p>
	* If the NAR has more than one dependency of {@code type} {@code nar}, then the
	* Maven NAR plugin will fail to build the NAR.
	* </p>
	*/
	public class NarClassLoader extends URLClassLoader {

	private static final Logger LOGGER = LoggerFactory.getLogger(NarClassLoader.class);

	private static final FileFilter JAR_FILTER = new FileFilter() {
	@Override
	public boolean accept(File pathname) {
	final String nameToTest = pathname.getName().toLowerCase();
	return nameToTest.endsWith(".jar") && pathname.isFile();
	}
	};

	/**
	* The NAR for which this <tt>ClassLoader</tt> is responsible.
	*/
	private final File narWorkingDirectory;

	/**
	* Construct a nar class loader.
	*
	* @param narWorkingDirectory directory to explode nar contents to
	* @throws IllegalArgumentException if the NAR is missing the Java Services
	* API file for <tt>FlowFileProcessor</tt> implementations.
	* @throws ClassNotFoundException if any of the <tt>FlowFileProcessor</tt>
	* implementations defined by the Java Services API cannot be loaded.
	* @throws IOException if an error occurs while loading the NAR.
	*/
	public NarClassLoader(final File narWorkingDirectory) throws ClassNotFoundException, IOException {
	super(new URL[0]);
	this.narWorkingDirectory = narWorkingDirectory;

	// process the classpath
	updateClasspath(narWorkingDirectory);
	}

	/**
	* Construct a nar class loader with the specific parent.
	*
	* @param narWorkingDirectory directory to explode nar contents to
	* @param parentClassLoader parent class loader of this nar
	* @throws IllegalArgumentException if the NAR is missing the Java Services
	* API file for <tt>FlowFileProcessor</tt> implementations.
	* @throws ClassNotFoundException if any of the <tt>FlowFileProcessor</tt>
	* implementations defined by the Java Services API cannot be loaded.
	* @throws IOException if an error occurs while loading the NAR.
	*/
	public NarClassLoader(final File narWorkingDirectory, final ClassLoader parentClassLoader) throws ClassNotFoundException, IOException {
	super(new URL[0], parentClassLoader);
	this.narWorkingDirectory = narWorkingDirectory;

	// process the classpath
	updateClasspath(narWorkingDirectory);
	}

	public File getWorkingDirectory() {
	return narWorkingDirectory;
	}

	/**
	* Adds URLs for the resources unpacked from this NAR:
	* <ul><li>the root: for classes, <tt>META-INF</tt>, etc.</li>
	* <li><tt>META-INF/dependencies</tt>: for config files, <tt>.so</tt>s,
	* etc.</li>
	* <li><tt>META-INF/dependencies/*.jar</tt>: for dependent
	* libraries</li></ul>
	*
	* @param root the root directory of the unpacked NAR.
	* @throws IOException if the URL list could not be updated.
	*/
	private void updateClasspath(File root) throws IOException {
	addURL(root.toURI().toURL()); // for compiled classes, META-INF/, etc.

	File dependencies = new File(root, "META-INF/bundled-dependencies");
	if (!dependencies.isDirectory()) {
	LOGGER.warn(narWorkingDirectory + " does not contain META-INF/bundled-dependencies!");
	}
	addURL(dependencies.toURI().toURL());
	if (dependencies.isDirectory()) {
	for (File libJar : dependencies.listFiles(JAR_FILTER)) {
	addURL(libJar.toURI().toURL());
	}
	}
	}

	@Override
	protected String findLibrary(final String libname) {
	File dependencies = new File(narWorkingDirectory, "META-INF/bundled-dependencies");
	if (!dependencies.isDirectory()) {
	LOGGER.warn(narWorkingDirectory + " does not contain META-INF/bundled-dependencies!");
	}

	final File nativeDir = new File(dependencies, "native");
	final File libsoFile = new File(nativeDir, "lib" + libname + ".so");
	final File dllFile = new File(nativeDir, libname + ".dll");
	final File soFile = new File(nativeDir, libname + ".so");
	if (libsoFile.exists()) {
	return libsoFile.getAbsolutePath();
	} else if (dllFile.exists()) {
	return dllFile.getAbsolutePath();
	} else if (soFile.exists()) {
	return soFile.getAbsolutePath();
	}

	// not found in the nar. try system native dir
	return null;
	}

	@Override
	public String toString() {
	return NarClassLoader.class.getName() + "[" + narWorkingDirectory.getPath() + "]";
	}
	}