| /** |
| * 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.pulsar.functions.instance; |
| |
| import java.io.File; |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.net.MalformedURLException; |
| import java.net.URL; |
| import java.net.URLClassLoader; |
| import java.util.Arrays; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| /** |
| * This is the initial class that gets called when starting a Java Function instance. |
| * Multiple class loaders are used to separate function instance dependencies from user code dependencies |
| * This class will create three classloaders: |
| * 1. The root classloader that will share interfaces between the function instance |
| * classloader and user code classloader. This classloader will contain the following dependencies |
| * - pulsar-io-core |
| * - pulsar-functions-api |
| * - pulsar-client-api |
| * - log4j-slf4j-impl |
| * - slf4j-api |
| * - log4j-core |
| * - log4j-api |
| * |
| * 2. The Function instance classloader, a child of the root classloader, that loads all pulsar broker/worker dependencies |
| * 3. The user code classloader, a child of the root classloader, that loads all user code dependencies |
| * |
| * This class should not use any other dependencies! |
| * |
| */ |
| public class JavaInstanceMain { |
| |
| private static final String FUNCTIONS_INSTANCE_CLASSPATH = "pulsar.functions.instance.classpath"; |
| |
| public JavaInstanceMain() { } |
| |
| public static void main(String[] args) throws Exception { |
| |
| // Set root classloader to current classpath |
| ClassLoader root = Thread.currentThread().getContextClassLoader(); |
| |
| // Get classpath for function instance |
| String functionInstanceClasspath = System.getProperty(FUNCTIONS_INSTANCE_CLASSPATH); |
| if (functionInstanceClasspath == null) { |
| throw new IllegalArgumentException("Property " + FUNCTIONS_INSTANCE_CLASSPATH + " is not set!"); |
| } |
| |
| List<File> files = new LinkedList<>(); |
| for (String entry: functionInstanceClasspath.split(":")) { |
| if (isBlank(entry)) { |
| continue; |
| } |
| // replace any asterisks i.e. wildcards as they don't work with url classloader |
| File f = new File(entry.replace("*", "")); |
| if (f.exists()) { |
| if (f.isDirectory()) { |
| files.addAll(Arrays.asList(f.listFiles())); |
| } else { |
| files.add(new File(entry)); |
| } |
| } else { |
| System.out.println(String.format("[WARN] %s on functions instance classpath does not exist", f.getAbsolutePath())); |
| } |
| } |
| |
| ClassLoader functionInstanceClsLoader = loadJar(root, files.toArray(new File[files.size()])); |
| |
| System.out.println("Using function root classloader: " + root); |
| System.out.println("Using function instance classloader: " + functionInstanceClsLoader); |
| |
| // use the function instance classloader to create org.apache.pulsar.functions.runtime.JavaInstanceStarter |
| Object main = createInstance("org.apache.pulsar.functions.runtime.JavaInstanceStarter", functionInstanceClsLoader); |
| |
| // Invoke start method of JavaInstanceStarter to start the function instance code |
| Method method = main.getClass().getDeclaredMethod("start", String[].class, ClassLoader.class, ClassLoader.class); |
| |
| System.out.println("Starting function instance..."); |
| method.invoke(main, args, functionInstanceClsLoader, root); |
| } |
| |
| public static Object createInstance(String userClassName, |
| ClassLoader classLoader) { |
| Class<?> theCls; |
| try { |
| theCls = Class.forName(userClassName, true, classLoader); |
| } catch (ClassNotFoundException | NoClassDefFoundError cnfe) { |
| throw new RuntimeException("Class " + userClassName + " must be in class path", cnfe); |
| } |
| Object result; |
| try { |
| Constructor<?> meth = theCls.getDeclaredConstructor(); |
| meth.setAccessible(true); |
| |
| result = meth.newInstance(); |
| } catch (InstantiationException ie) { |
| throw new RuntimeException("User class must be concrete", ie); |
| } catch (NoSuchMethodException e) { |
| throw new RuntimeException("Class " + userClassName + " doesn't have such method", e); |
| } catch (IllegalAccessException e) { |
| throw new RuntimeException("Class " + userClassName + " must have a no-arg constructor", e); |
| } catch (InvocationTargetException e) { |
| throw new RuntimeException("Class " + userClassName + " constructor throws exception", e); |
| } |
| return result; |
| } |
| |
| public static ClassLoader loadJar(ClassLoader parent, File[] jars) throws MalformedURLException { |
| URL[] urls = new URL[jars.length]; |
| for (int i = 0; i < jars.length; i++) { |
| urls[i] = jars[i].toURI().toURL(); |
| } |
| return new URLClassLoader(urls, parent); |
| } |
| |
| public static boolean isBlank(String str) { |
| int strLen; |
| if (str != null && (strLen = str.length()) != 0) { |
| for(int i = 0; i < strLen; ++i) { |
| if (!Character.isWhitespace(str.charAt(i))) { |
| return false; |
| } |
| } |
| |
| return true; |
| } else { |
| return true; |
| } |
| } |
| } |