| /* |
| * Copyright (C) 2010 The Guava Authors |
| * |
| * Licensed 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 com.google.common.util.concurrent; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.lang.Thread.UncaughtExceptionHandler; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| /** |
| * A ThreadFactory builder, providing any combination of these features: |
| * <ul> |
| * <li> whether threads should be marked as {@linkplain Thread#setDaemon daemon} |
| * threads |
| * <li> a {@linkplain ThreadFactoryBuilder#setNameFormat naming format} |
| * <li> a {@linkplain Thread#setPriority thread priority} |
| * <li> an {@linkplain Thread#setUncaughtExceptionHandler uncaught exception |
| * handler} |
| * <li> a {@linkplain ThreadFactory#newThread backing thread factory} |
| * </ul> |
| * <p>If no backing thread factory is provided, a default backing thread factory is |
| * used as if by calling {@code setThreadFactory(}{@link |
| * Executors#defaultThreadFactory()}{@code )}. |
| * |
| * @author Kurt Alfred Kluever |
| * @since 4.0 |
| */ |
| public final class ThreadFactoryBuilder { |
| private String nameFormat = null; |
| private Boolean daemon = null; |
| private Integer priority = null; |
| private UncaughtExceptionHandler uncaughtExceptionHandler = null; |
| private ThreadFactory backingThreadFactory = null; |
| |
| /** |
| * Creates a new {@link ThreadFactory} builder. |
| */ |
| public ThreadFactoryBuilder() {} |
| |
| /** |
| * Sets the naming format to use when naming threads ({@link Thread#setName}) |
| * which are created with this ThreadFactory. |
| * |
| * @param nameFormat a {@link String#format(String, Object...)}-compatible |
| * format String, to which a unique integer (0, 1, etc.) will be supplied |
| * as the single parameter. This integer will be unique to the built |
| * instance of the ThreadFactory and will be assigned sequentially. For |
| * example, {@code "rpc-pool-%d"} will generate thread names like |
| * {@code "rpc-pool-0"}, {@code "rpc-pool-1"}, {@code "rpc-pool-2"}, etc. |
| * @return this for the builder pattern |
| */ |
| @SuppressWarnings("ReturnValueIgnored") |
| public ThreadFactoryBuilder setNameFormat(String nameFormat) { |
| String.format(nameFormat, 0); // fail fast if the format is bad or null |
| this.nameFormat = nameFormat; |
| return this; |
| } |
| |
| /** |
| * Sets daemon or not for new threads created with this ThreadFactory. |
| * |
| * @param daemon whether or not new Threads created with this ThreadFactory |
| * will be daemon threads |
| * @return this for the builder pattern |
| */ |
| public ThreadFactoryBuilder setDaemon(boolean daemon) { |
| this.daemon = daemon; |
| return this; |
| } |
| |
| /** |
| * Sets the priority for new threads created with this ThreadFactory. |
| * |
| * @param priority the priority for new Threads created with this |
| * ThreadFactory |
| * @return this for the builder pattern |
| */ |
| public ThreadFactoryBuilder setPriority(int priority) { |
| // Thread#setPriority() already checks for validity. These error messages |
| // are nicer though and will fail-fast. |
| checkArgument(priority >= Thread.MIN_PRIORITY, |
| "Thread priority (%s) must be >= %s", priority, Thread.MIN_PRIORITY); |
| checkArgument(priority <= Thread.MAX_PRIORITY, |
| "Thread priority (%s) must be <= %s", priority, Thread.MAX_PRIORITY); |
| this.priority = priority; |
| return this; |
| } |
| |
| /** |
| * Sets the {@link UncaughtExceptionHandler} for new threads created with this |
| * ThreadFactory. |
| * |
| * @param uncaughtExceptionHandler the uncaught exception handler for new |
| * Threads created with this ThreadFactory |
| * @return this for the builder pattern |
| */ |
| public ThreadFactoryBuilder setUncaughtExceptionHandler( |
| UncaughtExceptionHandler uncaughtExceptionHandler) { |
| this.uncaughtExceptionHandler = checkNotNull(uncaughtExceptionHandler); |
| return this; |
| } |
| |
| /** |
| * Sets the backing {@link ThreadFactory} for new threads created with this |
| * ThreadFactory. Threads will be created by invoking #newThread(Runnable) on |
| * this backing {@link ThreadFactory}. |
| * |
| * @param backingThreadFactory the backing {@link ThreadFactory} which will |
| * be delegated to during thread creation. |
| * @return this for the builder pattern |
| * |
| * @see MoreExecutors |
| */ |
| public ThreadFactoryBuilder setThreadFactory( |
| ThreadFactory backingThreadFactory) { |
| this.backingThreadFactory = checkNotNull(backingThreadFactory); |
| return this; |
| } |
| |
| /** |
| * Returns a new thread factory using the options supplied during the building |
| * process. After building, it is still possible to change the options used to |
| * build the ThreadFactory and/or build again. State is not shared amongst |
| * built instances. |
| * |
| * @return the fully constructed {@link ThreadFactory} |
| */ |
| public ThreadFactory build() { |
| return build(this); |
| } |
| |
| private static ThreadFactory build(ThreadFactoryBuilder builder) { |
| final String nameFormat = builder.nameFormat; |
| final Boolean daemon = builder.daemon; |
| final Integer priority = builder.priority; |
| final UncaughtExceptionHandler uncaughtExceptionHandler = |
| builder.uncaughtExceptionHandler; |
| final ThreadFactory backingThreadFactory = |
| (builder.backingThreadFactory != null) |
| ? builder.backingThreadFactory |
| : Executors.defaultThreadFactory(); |
| final AtomicLong count = (nameFormat != null) ? new AtomicLong(0) : null; |
| return new ThreadFactory() { |
| @Override public Thread newThread(Runnable runnable) { |
| Thread thread = backingThreadFactory.newThread(runnable); |
| if (nameFormat != null) { |
| thread.setName(String.format(nameFormat, count.getAndIncrement())); |
| } |
| if (daemon != null) { |
| thread.setDaemon(daemon); |
| } |
| if (priority != null) { |
| thread.setPriority(priority); |
| } |
| if (uncaughtExceptionHandler != null) { |
| thread.setUncaughtExceptionHandler(uncaughtExceptionHandler); |
| } |
| return thread; |
| } |
| }; |
| } |
| } |