/**
* 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.tez.common;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.tez.dag.api.TezUncheckedException;
@Private
public class ReflectionUtils {
private static final Map<String, Class<?>> CLAZZ_CACHE = new ConcurrentHashMap<String, Class<?>>();
@Private
public static Class<?> getClazz(String className) {
Class<?> clazz = CLAZZ_CACHE.get(className);
if (clazz == null) {
try {
clazz = Class.forName(className, true, Thread.currentThread().getContextClassLoader());
} catch (ClassNotFoundException e) {
throw new TezUncheckedException("Unable to load class: " + className, e);
}
}
return clazz;
}
private static <T> T getNewInstance(Class<T> clazz) {
T instance;
try {
instance = clazz.newInstance();
} catch (InstantiationException e) {
throw new TezUncheckedException(
"Unable to instantiate class with 0 arguments: " + clazz.getName(), e);
} catch (IllegalAccessException e) {
throw new TezUncheckedException(
"Unable to instantiate class with 0 arguments: " + clazz.getName(), e);
}
return instance;
}
private static <T> T getNewInstance(Class<T> clazz, Class<?>[] parameterTypes, Object[] parameters) {
T instance;
try {
Constructor<T> constructor = clazz.getConstructor(parameterTypes);
instance = constructor.newInstance(parameters);
} catch (InstantiationException e) {
throw new TezUncheckedException(
"Unable to instantiate class with " + parameters.length + " arguments: " + clazz.getName(), e);
} catch (IllegalAccessException e) {
throw new TezUncheckedException(
"Unable to instantiate class with " + parameters.length + " arguments: " + clazz.getName(), e);
} catch (NoSuchMethodException e) {
throw new TezUncheckedException(
"Unable to instantiate class with " + parameters.length + " arguments: " + clazz.getName(), e);
} catch (InvocationTargetException e) {
throw new TezUncheckedException(
"Unable to instantiate class with " + parameters.length + " arguments: " + clazz.getName(), e);
}
return instance;
}
@Private
public static <T> T createClazzInstance(String className) {
Class<?> clazz = getClazz(className);
@SuppressWarnings("unchecked")
T instance = (T) getNewInstance(clazz);
return instance;
}
@Private
public static <T> T createClazzInstance(String className, Class<?>[] parameterTypes, Object[] parameters) {
Class<?> clazz = getClazz(className);
@SuppressWarnings("unchecked")
T instance = (T) getNewInstance(clazz, parameterTypes, parameters);
return instance;
}
@Private
public static synchronized void addResourcesToClasspath(List<URL> urls) {
ClassLoader classLoader = new URLClassLoader(urls.toArray(new URL[urls.size()]), Thread
.currentThread().getContextClassLoader());
Thread.currentThread().setContextClassLoader(classLoader);
}
// Parameters for addResourcesToSystemClassLoader
private static final Class<?>[] parameters = new Class[]{URL.class};
private static Method sysClassLoaderMethod = null;
@Private
public static synchronized void addResourcesToSystemClassLoader(List<URL> urls) {
URLClassLoader sysLoader = (URLClassLoader)ClassLoader.getSystemClassLoader();
if (sysClassLoaderMethod == null) {
Class<?> sysClass = URLClassLoader.class;
Method method;
try {
method = sysClass.getDeclaredMethod("addURL", parameters);
} catch (SecurityException e) {
throw new TezUncheckedException("Failed to get handle on method addURL", e);
} catch (NoSuchMethodException e) {
throw new TezUncheckedException("Failed to get handle on method addURL", e);
}
method.setAccessible(true);
sysClassLoaderMethod = method;
}
for (URL url : urls) {
try {
sysClassLoaderMethod.invoke(sysLoader, new Object[] { url });
} catch (IllegalArgumentException e) {
throw new TezUncheckedException("Failed to invoke addURL for rsrc: " + url, e);
} catch (IllegalAccessException e) {
throw new TezUncheckedException("Failed to invoke addURL for rsrc: " + url, e);
} catch (InvocationTargetException e) {
throw new TezUncheckedException("Failed to invoke addURL for rsrc: " + url, e);
}
}
}
}