content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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.alibaba.nacos.common.utils;
  
  import java.util.Locale;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * build thread factory.
   * @author zzq
   * @date 2021/8/3
   */
  public class ThreadFactoryBuilder {
      
      /**
       *  Whether it is a daemon thread.
       */
      private Boolean daemon = false;
      
      /**
       *   Thread priority.
       */
      private Integer priority = null;
      
      /**
       *   Thread name template.
       */
      private String nameFormat = null;
      
      /**
       *   Uncaught exception handler.
       */
      private Thread.UncaughtExceptionHandler uncaughtExceptionHandler = null;
  
      /**
       *   Customize thread factory.
       */
      private ThreadFactory customizeFactory = null;
      
      /**
       * set nameFormat property.
       */
      public ThreadFactoryBuilder nameFormat(String nameFormat) {
          checkNullParameter(nameFormat, "nameFormat cannot be null.");
          this.nameFormat = nameFormat;
          return this;
      }
      
      /**
       * set priority property.
       */
      public ThreadFactoryBuilder priority(int priority) {
          if (priority > Thread.MAX_PRIORITY || priority < Thread.MIN_PRIORITY) {
              throw new IllegalArgumentException(
                      String.format("The value of priority should be between %s and %s", Thread.MIN_PRIORITY + 1, Thread.MAX_PRIORITY + 1)
              );
          }
          this.priority = priority;
          return this;
      }
      
      /**
       * set uncaughtExceptionHandler property.
       */
      public ThreadFactoryBuilder uncaughtExceptionHandler(
              Thread.UncaughtExceptionHandler uncaughtExceptionHandler) {
          checkNullParameter(uncaughtExceptionHandler, "uncaughtExceptionHandler cannot be null.");
          this.uncaughtExceptionHandler = uncaughtExceptionHandler;
          return this;
      }
      
      /**
       * set daemon property.
       */
      public ThreadFactoryBuilder daemon(boolean daemon) {
          this.daemon = daemon;
          return this;
      }
      
      /**
       * set customizeFactory property.
       */
      public ThreadFactoryBuilder customizeFactory(ThreadFactory factory) {
          checkNullParameter(factory, "factory cannot be null.");
          this.customizeFactory = factory;
          return this;
      }
      
      /**
       *  build thread factory.
       */
      public ThreadFactory build() {
          ThreadFactory factory = customizeFactory == null ? Executors.defaultThreadFactory() : customizeFactory;
          final AtomicLong count = (nameFormat != null) ? new AtomicLong(0) : null;
          return r -> {
              Thread thread = factory.newThread(r);
              if (nameFormat != null) {
                  thread.setName(format(nameFormat, count.getAndIncrement()));
              }
              if (priority != null) {
                  thread.setPriority(priority);
              }
              if (uncaughtExceptionHandler != null) {
                  thread.setUncaughtExceptionHandler(uncaughtExceptionHandler);
              }
              thread.setDaemon(daemon);
              return thread;
          };
      }
      
      private String format(String format, Object... args) {
          return String.format(Locale.ROOT, format, args);
      }
      
      private void checkNullParameter(Object obj, String msg) {
          if (obj == null) {
              throw new IllegalArgumentException(msg);
          }
      }
  }
  