javadoc.src-html.com.google.common.util.concurrent.UncaughtExceptionHandlers.html Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of guava-osgi
Repackaging of Google Guava libraries as OSGi bundle
The newest version!


001    /*
002     * Copyright (C) 2010 The Guava Authors
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package com.google.common.util.concurrent;
018    
019    import static java.util.logging.Level.SEVERE;
020    
021    import com.google.common.annotations.VisibleForTesting;
022    
023    import java.lang.Thread.UncaughtExceptionHandler;
024    import java.util.logging.Logger;
025    
026    /**
027     * Factories for {@link UncaughtExceptionHandler} instances.
028     *
029     * @author Gregory Kick
030     * @since 8.0
031     */
032    public final class UncaughtExceptionHandlers {
033      private UncaughtExceptionHandlers() {}
034    
035      /**
036       * Returns an exception handler that exits the system. This is particularly useful for the main
037       * thread, which may start up other, non-daemon threads, but fail to fully initialize the
038       * application successfully.
039       *
040       * <p>Example usage:
041       * <pre>public static void main(String[] args) {
042       *   Thread.currentThread().setUncaughtExceptionHandler(UncaughtExceptionHandlers.systemExit());
043       *   ...
044       * </pre>
045       */
046      public static UncaughtExceptionHandler systemExit() {
047        return new Exiter(Runtime.getRuntime());
048      }
049    
050      @VisibleForTesting static final class Exiter implements UncaughtExceptionHandler {
051        private static final Logger logger = Logger.getLogger(Exiter.class.getName());
052    
053        private final Runtime runtime;
054    
055        Exiter(Runtime runtime) {
056          this.runtime = runtime;
057        }
058    
059        @Override public void uncaughtException(Thread t, Throwable e) {
060          // cannot use FormattingLogger due to a dependency loop
061          logger.log(SEVERE, String.format("Caught an exception in %s.  Shutting down.", t), e);
062          runtime.exit(1);
063        }
064      }
065    }