1 /* 2 * Copyright (C) 2006 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.util.concurrent; 18 19 import java.util.concurrent.Executors; 20 import java.util.concurrent.ThreadFactory; 21 import java.util.concurrent.atomic.AtomicInteger; 22 23 /** 24 * A ThreadFactory which decorates another ThreadFactory to set a name on 25 * each thread created. 26 * 27 * @author Kevin Bourrillion 28 * @since 2009.09.15 <b>tentative</b> 29 */ 30 public class NamingThreadFactory implements ThreadFactory { 31 private final ThreadFactory backingFactory; 32 private final String format; 33 private final AtomicInteger count = new AtomicInteger(0); 34 35 public static final ThreadFactory DEFAULT_FACTORY 36 = Executors.defaultThreadFactory(); 37 38 /** 39 * Creates a new factory that delegates to the default thread factory for 40 * thread creation, then uses {@code format} to construct a name for the new 41 * thread. 42 * 43 * @param format a {@link String#format(String, Object...)}-compatible format 44 * String, to which a unique integer (0, 1, etc.) will be supplied as the 45 * single parameter. This integer will be unique to this instance of 46 * NamingThreadFactory and will be assigned sequentially. 47 */ NamingThreadFactory(String format)48 public NamingThreadFactory(String format) { 49 this(format, DEFAULT_FACTORY); 50 } 51 52 /** 53 * Creates a new factory that delegates to {@code backingFactory} for thread 54 * creation, then uses {@code format} to construct a name for the new thread. 55 * 56 * @param format a {@link String#format(String, Object...)}-compatible format 57 * String, to which a unique integer (0, 1, etc.) will be supplied as the 58 * single parameter 59 * @param backingFactory the factory that will actually create the threads 60 * @throws java.util.IllegalFormatException if {@code format} is invalid 61 */ NamingThreadFactory(String format, ThreadFactory backingFactory)62 public NamingThreadFactory(String format, ThreadFactory backingFactory) { 63 this.format = format; 64 this.backingFactory = backingFactory; 65 makeName(0); // fail fast if format is bad 66 } 67 newThread(Runnable r)68 public Thread newThread(Runnable r) { 69 Thread t = backingFactory.newThread(r); 70 t.setName(makeName(count.getAndIncrement())); 71 return t; 72 } 73 makeName(int ordinal)74 private String makeName(int ordinal) { 75 return String.format(format, ordinal); 76 } 77 } 78