org.apache.flink.util.LambdaUtil Maven / Gradle / Ivy
/*
* 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.flink.util;
import org.apache.flink.util.function.SupplierWithException;
import org.apache.flink.util.function.ThrowingConsumer;
import org.apache.flink.util.function.ThrowingRunnable;
/**
* This class offers utility functions for Java's lambda features.
*/
public final class LambdaUtil {
private LambdaUtil() {
throw new AssertionError();
}
/**
* This method supplies all elements from the input to the consumer. Exceptions that happen on elements are
* suppressed until all elements are processed. If exceptions happened for one or more of the inputs, they are
* reported in a combining suppressed exception.
*
* @param inputs iterator for all inputs to the throwingConsumer.
* @param throwingConsumer this consumer will be called for all elements delivered by the input iterator.
* @param the type of input.
* @throws Exception collected exceptions that happened during the invocation of the consumer on the input elements.
*/
public static void applyToAllWhileSuppressingExceptions(
Iterable inputs,
ThrowingConsumer throwingConsumer) throws Exception {
if (inputs != null && throwingConsumer != null) {
Exception exception = null;
for (T input : inputs) {
if (input != null) {
try {
throwingConsumer.accept(input);
} catch (Exception ex) {
exception = ExceptionUtils.firstOrSuppressed(ex, exception);
}
}
}
if (exception != null) {
throw exception;
}
}
}
/**
* Runs the given runnable with the given ClassLoader as the thread's
* {@link Thread#setContextClassLoader(ClassLoader) context class loader}.
*
* The method will make sure to set the context class loader of the calling thread
* back to what it was before after the runnable completed.
*/
public static void withContextClassLoader(
final ClassLoader cl,
final ThrowingRunnable r) throws E {
final Thread currentThread = Thread.currentThread();
final ClassLoader oldClassLoader = currentThread.getContextClassLoader();
try {
currentThread.setContextClassLoader(cl);
r.run();
}
finally {
currentThread.setContextClassLoader(oldClassLoader);
}
}
/**
* Runs the given runnable with the given ClassLoader as the thread's
* {@link Thread#setContextClassLoader(ClassLoader) context class loader}.
*
* The method will make sure to set the context class loader of the calling thread
* back to what it was before after the runnable completed.
*/
public static R withContextClassLoader(
final ClassLoader cl,
final SupplierWithException s) throws E {
final Thread currentThread = Thread.currentThread();
final ClassLoader oldClassLoader = currentThread.getContextClassLoader();
try {
currentThread.setContextClassLoader(cl);
return s.get();
}
finally {
currentThread.setContextClassLoader(oldClassLoader);
}
}
}