Java Thread pool rejection policy

Class diagram for thread pool rejection policy: roughly seven or so

Look at the source code of each class:

AbortPolicy (direct throw exception)

public static class AbortPolicy implements RejectedExecutionHandler {        public AbortPolicy() { }        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {            throw new RejectedExecutionException("Task " + r.toString" rejected from " + e.toString());        }    }

Abortpolicywithreport (logging)

public class Abortpolicywithreport extends Threadpoolexecutor.abortpolicy {static private final Logger Logger = Logger     Init.logger;    Private final String ThreadName;    Private final URL url;        Public Abortpolicywithreport (String threadname, url url) {this.threadname = ThreadName;    This.url = URL; } @Override public void Rejectedexecution (Runnable R, Threadpoolexecutor e) {String msg = String.Format ("Thr EAD Pool is exhausted! "+" Thread Name:%s, pool Size:%d (active:%d, Core:%d, Max:%d, largest:%d), Ta SK:%d (completed:%d), "+" Executor Status: (isshutdown:%s, isterminated:%s, isterminating:%s), in%s://%s :%d! ", ThreadName, E.getpoolsize (), E.getactivecount (), E.getcorepoolsize (), E.getmaximumpoolsize (), E.get Largestpoolsize (), E.gettaskcount (), E.getcompletedtaskcount (), E.isshutdown (), e.isterminated (), E.isTermi Nating (), Url.getprotocol (), Url.getip (), Url.getporT ());        Logger.warn (msg);    throw new Rejectedexecutionexception (msg); }}

Callerrunspolicy (caller execution)

public static class CallerRunsPolicy implements RejectedExecutionHandler {        public CallerRunsPolicy() { }        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {            if (!e.isShutdown()) {                r.run();            }        }    }

Discardoldestpolicy (discards the oldest unhandled task in the thread pool)

public static class DiscardOldestPolicy implements RejectedExecutionHandler {        public DiscardOldestPolicy() { }        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {            if (!e.isShutdown()) {                e.getQueue().poll();                e.execute(r);            }        }    }

Discardpolicy (direct refusal, no processing)

public static class DiscardPolicy implements RejectedExecutionHandler {        public DiscardPolicy() { }        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {        }    }

Ignorerunspolicy (Ignore run test, dump JVM information)

private static class IgnoreRunsPolicy implements RejectedExecutionHandler {        private final static Logger LOGGER = LoggerInit.LOGGER;        public volatile boolean hasDump = false;        public IgnoreRunsPolicy() {        }        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {            dumpJVMInfo();  ?//方法太长不予展示，就是这个dump jvm信息的意思            // ignore it when thread full and it will be timeout response for client            throw new RejectedExecutionException();        }

Newthreadrunspolicy (Create a new temporary thread inside the memoryawarethreadpoolexecutor to handle)

private static final class NewThreadRunsPolicy implements RejectedExecutionHandler {        public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {            try {                final Thread t = new Thread(r, "Temporary task executor");                t.start();            } catch (Throwable e) {                throw new RejectedExecutionException(                        "Failed to start a new thread", e);            }        }    }

Reading the source is not the thread pool rejected the policy has a deeper understanding?

Java Thread pool rejection policy