Statement unnecessarily nested within else clause.
This commit is contained in:
ggregory
parent
b2ec67b54a
commit
5e5ba1b812
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@ -1,466 +1,460 @@
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/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.apache.commons.lang3;
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import java.util.ArrayList;
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import java.util.Collection;
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import java.util.Collections;
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import java.util.List;
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/**
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* <p>
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* Helpers for {@code java.lang.Thread} and {@code java.lang.ThreadGroup}.
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* </p>
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* <p>
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* #ThreadSafe#
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* </p>
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*
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* @see java.lang.Thread
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* @see java.lang.ThreadGroup
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* @since 3.5
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*/
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public class ThreadUtils {
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/**
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* Return the active thread with the specified id if it belong's to the specified thread group.
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*
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* @param threadId The thread id
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* @param threadGroup The thread group
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* @return The thread which belongs to a specified thread group and the thread's id match the specified id.
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* {@code null} is returned if no such thread exists
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* @throws IllegalArgumentException if the specified id is zero or negative or the group is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Thread findThreadById(final long threadId, final ThreadGroup threadGroup) {
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if (threadGroup == null) {
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throw new IllegalArgumentException("The thread group must not be null");
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}
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final Thread thread = findThreadById(threadId);
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if(thread != null && threadGroup.equals(thread.getThreadGroup())) {
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return thread;
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}
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return null;
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}
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/**
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* Return the active thread with the specified id if it belong's to a thread group with the specified group name.
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*
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* @param threadId The thread id
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* @param threadGroupName The thread group name
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* @return The threads which belongs to a thread group with the specified group name and the thread's id match the specified id.
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* {@code null} is returned if no such thread exists
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* @throws IllegalArgumentException if the specified id is zero or negative or the group name is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Thread findThreadById(final long threadId, final String threadGroupName) {
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if (threadGroupName == null) {
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throw new IllegalArgumentException("The thread group name must not be null");
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}
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final Thread thread = findThreadById(threadId);
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if(thread != null && thread.getThreadGroup() != null && thread.getThreadGroup().getName().equals(threadGroupName)) {
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return thread;
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}
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return null;
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}
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/**
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* Return active threads with the specified name if they belong to a specified thread group.
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*
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* @param threadName The thread name
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* @param threadGroup The thread group
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* @return The threads which belongs to a thread group and the thread's name match the specified name,
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* An empty collection is returned if no such thread exists. The collection returned is always unmodifiable.
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* @throws IllegalArgumentException if the specified thread name or group is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> findThreadsByName(final String threadName, final ThreadGroup threadGroup) {
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return findThreads(threadGroup, false, new NamePredicate(threadName));
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}
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/**
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* Return active threads with the specified name if they belong to a thread group with the specified group name.
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*
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* @param threadName The thread name
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* @param threadGroupName The thread group name
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* @return The threads which belongs to a thread group with the specified group name and the thread's name match the specified name,
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* An empty collection is returned if no such thread exists. The collection returned is always unmodifiable.
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* @throws IllegalArgumentException if the specified thread name or group name is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> findThreadsByName(final String threadName, final String threadGroupName) {
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if (threadName == null) {
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throw new IllegalArgumentException("The thread name must not be null");
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}
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if (threadGroupName == null) {
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throw new IllegalArgumentException("The thread group name must not be null");
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}
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final Collection<ThreadGroup> threadGroups = findThreadGroups(new NamePredicate(threadGroupName));
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if(threadGroups.isEmpty()) {
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return Collections.emptyList();
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}
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final Collection<Thread> result = new ArrayList<Thread>();
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final NamePredicate threadNamePredicate = new NamePredicate(threadName);
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for(final ThreadGroup group : threadGroups) {
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result.addAll(findThreads(group, false, threadNamePredicate));
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}
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return Collections.unmodifiableCollection(result);
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}
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/**
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* Return active thread groups with the specified group name.
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*
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* @param threadGroupName The thread group name
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* @return the thread groups with the specified group name or an empty collection if no such thread group exists. The collection returned is always unmodifiable.
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* @throws IllegalArgumentException if group name is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<ThreadGroup> findThreadGroupsByName(final String threadGroupName) {
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return findThreadGroups(new NamePredicate(threadGroupName));
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}
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/**
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* Return all active thread groups excluding the system thread group (A thread group is active if it has been not destroyed).
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*
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* @return all thread groups excluding the system thread group. The collection returned is always unmodifiable.
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<ThreadGroup> getAllThreadGroups() {
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return findThreadGroups(ALWAYS_TRUE_PREDICATE);
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}
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/**
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* Return the system thread group (sometimes also referred as "root thread group").
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*
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* @return the system thread group
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static ThreadGroup getSystemThreadGroup() {
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ThreadGroup threadGroup = Thread.currentThread().getThreadGroup();
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while(threadGroup.getParent() != null) {
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threadGroup = threadGroup.getParent();
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}
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return threadGroup;
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}
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/**
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* Return all active threads (A thread is active if it has been started and has not yet died).
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*
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* @return all active threads. The collection returned is always unmodifiable.
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> getAllThreads() {
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return findThreads(ALWAYS_TRUE_PREDICATE);
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}
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/**
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* Return active threads with the specified name.
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*
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* @param threadName The thread name
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* @return The threads with the specified name or an empty collection if no such thread exists. The collection returned is always unmodifiable.
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* @throws IllegalArgumentException if the specified name is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> findThreadsByName(final String threadName) {
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return findThreads(new NamePredicate(threadName));
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}
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/**
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* Return the active thread with the specified id.
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*
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* @param threadId The thread id
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* @return The thread with the specified id or {@code null} if no such thread exists
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* @throws IllegalArgumentException if the specified id is zero or negative
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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*
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Thread findThreadById(final long threadId) {
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final Collection<Thread> result = findThreads(new ThreadIdPredicate(threadId));
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if(result.isEmpty()) {
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return null;
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} else {
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return result.iterator().next();
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}
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}
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/**
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* <p>
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* ThreadUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
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* {@code ThreadUtils.getAllThreads()}
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* </p>
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* <p>
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* This constructor is public to permit tools that require a JavaBean instance to operate.
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* </p>
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*/
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public ThreadUtils() {
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super();
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}
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/**
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* A predicate for selecting threads.
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*/
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//if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
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public interface ThreadPredicate /*extends java.util.function.Predicate<Thread>*/{
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/**
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* Evaluates this predicate on the given thread.
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* @param thread the thread
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* @return {@code true} if the thread matches the predicate, otherwise {@code false}
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*/
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boolean test(Thread thread);
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}
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/**
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* A predicate for selecting threadgroups.
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*/
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//if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
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public interface ThreadGroupPredicate /*extends java.util.function.Predicate<ThreadGroup>*/{
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/**
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* Evaluates this predicate on the given threadgroup.
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* @param threadGroup the threadgroup
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* @return {@code true} if the threadGroup matches the predicate, otherwise {@code false}
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*/
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boolean test(ThreadGroup threadGroup);
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}
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/**
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* Predicate which always returns true.
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*/
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public static final AlwaysTruePredicate ALWAYS_TRUE_PREDICATE = new AlwaysTruePredicate();
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/**
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* A predicate implementation which always returns true.
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*/
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private final static class AlwaysTruePredicate implements ThreadPredicate, ThreadGroupPredicate{
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private AlwaysTruePredicate() {
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}
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@Override
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public boolean test(final ThreadGroup threadGroup) {
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return true;
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}
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@Override
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public boolean test(final Thread thread) {
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return true;
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}
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}
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/**
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* A predicate implementation which matches a thread or threadgroup name.
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*/
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public static class NamePredicate implements ThreadPredicate, ThreadGroupPredicate {
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private final String name;
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/**
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* Predicate constructor
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*
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* @param name thread or threadgroup name
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* @throws IllegalArgumentException if the name is {@code null}
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*/
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public NamePredicate(final String name) {
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super();
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if (name == null) {
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throw new IllegalArgumentException("The name must not be null");
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}
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this.name = name;
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}
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@Override
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public boolean test(final ThreadGroup threadGroup) {
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return threadGroup != null && threadGroup.getName().equals(name);
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}
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@Override
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public boolean test(final Thread thread) {
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return thread != null && thread.getName().equals(name);
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}
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}
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/**
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* A predicate implementation which matches a thread id.
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*/
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public static class ThreadIdPredicate implements ThreadPredicate {
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private final long threadId;
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/**
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* Predicate constructor
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*
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* @param threadId the threadId to match
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* @throws IllegalArgumentException if the threadId is zero or negative
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*/
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public ThreadIdPredicate(final long threadId) {
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super();
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if (threadId <= 0) {
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throw new IllegalArgumentException("The thread id must be greater than zero");
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}
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this.threadId = threadId;
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}
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@Override
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public boolean test(final Thread thread) {
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return thread != null && thread.getId() == threadId;
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}
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}
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/**
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* Select all active threads which match the given predicate.
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*
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* @param predicate the predicate
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* @return An unmodifiable {@code Collection} of active threads matching the given predicate
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*
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* @throws IllegalArgumentException if the predicate is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> findThreads(final ThreadPredicate predicate){
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return findThreads(getSystemThreadGroup(), true, predicate);
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}
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/**
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* Select all active threadgroups which match the given predicate.
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*
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* @param predicate the predicate
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* @return An unmodifiable {@code Collection} of active threadgroups matching the given predicate
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* @throws IllegalArgumentException if the predicate is null
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* @throws SecurityException
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* if the current thread cannot access the system thread group
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<ThreadGroup> findThreadGroups(final ThreadGroupPredicate predicate){
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return findThreadGroups(getSystemThreadGroup(), true, predicate);
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}
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/**
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* Select all active threads which match the given predicate and which belongs to the given thread group (or one of its subgroups).
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*
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* @param group the thread group
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* @param recurse if {@code true} then evaluate the predicate recursively on all threads in all subgroups of the given group
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* @param predicate the predicate
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* @return An unmodifiable {@code Collection} of active threads which match the given predicate and which belongs to the given thread group
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* @throws IllegalArgumentException if the given group or predicate is null
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* @throws SecurityException if the current thread cannot modify
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<Thread> findThreads(final ThreadGroup group, final boolean recurse, final ThreadPredicate predicate) {
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if (group == null) {
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throw new IllegalArgumentException("The group must not be null");
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}
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if (predicate == null) {
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throw new IllegalArgumentException("The predicate must not be null");
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}
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int count = group.activeCount();
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Thread[] threads;
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do {
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threads = new Thread[count + (count / 2) + 1]; //slightly grow the array size
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count = group.enumerate(threads, recurse);
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//return value of enumerate() must be strictly less than the array size according to javadoc
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} while (count >= threads.length);
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final List<Thread> result = new ArrayList<Thread>(count);
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for (int i = 0; i < count; ++i) {
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if (predicate.test(threads[i])) {
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result.add(threads[i]);
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}
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}
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return Collections.unmodifiableCollection(result);
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}
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/**
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* Select all active threadgroups which match the given predicate and which is a subgroup of the given thread group (or one of its subgroups).
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*
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* @param group the thread group
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* @param recurse if {@code true} then evaluate the predicate recursively on all threadgroups in all subgroups of the given group
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* @param predicate the predicate
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* @return An unmodifiable {@code Collection} of active threadgroups which match the given predicate and which is a subgroup of the given thread group
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* @throws IllegalArgumentException if the given group or predicate is null
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* @throws SecurityException if the current thread cannot modify
|
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* thread groups from this thread's thread group up to the system thread group
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*/
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public static Collection<ThreadGroup> findThreadGroups(final ThreadGroup group, final boolean recurse, final ThreadGroupPredicate predicate){
|
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if (group == null) {
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throw new IllegalArgumentException("The group must not be null");
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}
|
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if (predicate == null) {
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throw new IllegalArgumentException("The predicate must not be null");
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}
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|
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int count = group.activeGroupCount();
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ThreadGroup[] threadGroups;
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do {
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threadGroups = new ThreadGroup[count + (count / 2) + 1]; //slightly grow the array size
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count = group.enumerate(threadGroups, recurse);
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//return value of enumerate() must be strictly less than the array size according to javadoc
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} while(count >= threadGroups.length);
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final List<ThreadGroup> result = new ArrayList<ThreadGroup>(count);
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for(int i = 0; i < count; ++i) {
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if(predicate.test(threadGroups[i])) {
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result.add(threadGroups[i]);
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}
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}
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return Collections.unmodifiableCollection(result);
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}
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}
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/*
|
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* Licensed to the Apache Software Foundation (ASF) under one or more
|
||||
* contributor license agreements. See the NOTICE file distributed with
|
||||
* this work for additional information regarding copyright ownership.
|
||||
* The ASF licenses this file to You 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 org.apache.commons.lang3;
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import java.util.ArrayList;
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import java.util.Collection;
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import java.util.Collections;
|
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import java.util.List;
|
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|
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/**
|
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* <p>
|
||||
* Helpers for {@code java.lang.Thread} and {@code java.lang.ThreadGroup}.
|
||||
* </p>
|
||||
* <p>
|
||||
* #ThreadSafe#
|
||||
* </p>
|
||||
*
|
||||
* @see java.lang.Thread
|
||||
* @see java.lang.ThreadGroup
|
||||
* @since 3.5
|
||||
*/
|
||||
public class ThreadUtils {
|
||||
|
||||
/**
|
||||
* Return the active thread with the specified id if it belong's to the specified thread group.
|
||||
*
|
||||
* @param threadId The thread id
|
||||
* @param threadGroup The thread group
|
||||
* @return The thread which belongs to a specified thread group and the thread's id match the specified id.
|
||||
* {@code null} is returned if no such thread exists
|
||||
* @throws IllegalArgumentException if the specified id is zero or negative or the group is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Thread findThreadById(final long threadId, final ThreadGroup threadGroup) {
|
||||
if (threadGroup == null) {
|
||||
throw new IllegalArgumentException("The thread group must not be null");
|
||||
}
|
||||
final Thread thread = findThreadById(threadId);
|
||||
if(thread != null && threadGroup.equals(thread.getThreadGroup())) {
|
||||
return thread;
|
||||
}
|
||||
return null;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the active thread with the specified id if it belong's to a thread group with the specified group name.
|
||||
*
|
||||
* @param threadId The thread id
|
||||
* @param threadGroupName The thread group name
|
||||
* @return The threads which belongs to a thread group with the specified group name and the thread's id match the specified id.
|
||||
* {@code null} is returned if no such thread exists
|
||||
* @throws IllegalArgumentException if the specified id is zero or negative or the group name is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Thread findThreadById(final long threadId, final String threadGroupName) {
|
||||
if (threadGroupName == null) {
|
||||
throw new IllegalArgumentException("The thread group name must not be null");
|
||||
}
|
||||
final Thread thread = findThreadById(threadId);
|
||||
if(thread != null && thread.getThreadGroup() != null && thread.getThreadGroup().getName().equals(threadGroupName)) {
|
||||
return thread;
|
||||
}
|
||||
return null;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return active threads with the specified name if they belong to a specified thread group.
|
||||
*
|
||||
* @param threadName The thread name
|
||||
* @param threadGroup The thread group
|
||||
* @return The threads which belongs to a thread group and the thread's name match the specified name,
|
||||
* An empty collection is returned if no such thread exists. The collection returned is always unmodifiable.
|
||||
* @throws IllegalArgumentException if the specified thread name or group is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> findThreadsByName(final String threadName, final ThreadGroup threadGroup) {
|
||||
return findThreads(threadGroup, false, new NamePredicate(threadName));
|
||||
}
|
||||
|
||||
/**
|
||||
* Return active threads with the specified name if they belong to a thread group with the specified group name.
|
||||
*
|
||||
* @param threadName The thread name
|
||||
* @param threadGroupName The thread group name
|
||||
* @return The threads which belongs to a thread group with the specified group name and the thread's name match the specified name,
|
||||
* An empty collection is returned if no such thread exists. The collection returned is always unmodifiable.
|
||||
* @throws IllegalArgumentException if the specified thread name or group name is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> findThreadsByName(final String threadName, final String threadGroupName) {
|
||||
if (threadName == null) {
|
||||
throw new IllegalArgumentException("The thread name must not be null");
|
||||
}
|
||||
if (threadGroupName == null) {
|
||||
throw new IllegalArgumentException("The thread group name must not be null");
|
||||
}
|
||||
|
||||
final Collection<ThreadGroup> threadGroups = findThreadGroups(new NamePredicate(threadGroupName));
|
||||
|
||||
if(threadGroups.isEmpty()) {
|
||||
return Collections.emptyList();
|
||||
}
|
||||
|
||||
final Collection<Thread> result = new ArrayList<Thread>();
|
||||
final NamePredicate threadNamePredicate = new NamePredicate(threadName);
|
||||
for(final ThreadGroup group : threadGroups) {
|
||||
result.addAll(findThreads(group, false, threadNamePredicate));
|
||||
}
|
||||
return Collections.unmodifiableCollection(result);
|
||||
}
|
||||
|
||||
/**
|
||||
* Return active thread groups with the specified group name.
|
||||
*
|
||||
* @param threadGroupName The thread group name
|
||||
* @return the thread groups with the specified group name or an empty collection if no such thread group exists. The collection returned is always unmodifiable.
|
||||
* @throws IllegalArgumentException if group name is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<ThreadGroup> findThreadGroupsByName(final String threadGroupName) {
|
||||
return findThreadGroups(new NamePredicate(threadGroupName));
|
||||
}
|
||||
|
||||
/**
|
||||
* Return all active thread groups excluding the system thread group (A thread group is active if it has been not destroyed).
|
||||
*
|
||||
* @return all thread groups excluding the system thread group. The collection returned is always unmodifiable.
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<ThreadGroup> getAllThreadGroups() {
|
||||
return findThreadGroups(ALWAYS_TRUE_PREDICATE);
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the system thread group (sometimes also referred as "root thread group").
|
||||
*
|
||||
* @return the system thread group
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static ThreadGroup getSystemThreadGroup() {
|
||||
ThreadGroup threadGroup = Thread.currentThread().getThreadGroup();
|
||||
while(threadGroup.getParent() != null) {
|
||||
threadGroup = threadGroup.getParent();
|
||||
}
|
||||
return threadGroup;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return all active threads (A thread is active if it has been started and has not yet died).
|
||||
*
|
||||
* @return all active threads. The collection returned is always unmodifiable.
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> getAllThreads() {
|
||||
return findThreads(ALWAYS_TRUE_PREDICATE);
|
||||
}
|
||||
|
||||
/**
|
||||
* Return active threads with the specified name.
|
||||
*
|
||||
* @param threadName The thread name
|
||||
* @return The threads with the specified name or an empty collection if no such thread exists. The collection returned is always unmodifiable.
|
||||
* @throws IllegalArgumentException if the specified name is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> findThreadsByName(final String threadName) {
|
||||
return findThreads(new NamePredicate(threadName));
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the active thread with the specified id.
|
||||
*
|
||||
* @param threadId The thread id
|
||||
* @return The thread with the specified id or {@code null} if no such thread exists
|
||||
* @throws IllegalArgumentException if the specified id is zero or negative
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
*
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Thread findThreadById(final long threadId) {
|
||||
final Collection<Thread> result = findThreads(new ThreadIdPredicate(threadId));
|
||||
return result.isEmpty() ? null : result.iterator().next();
|
||||
}
|
||||
|
||||
/**
|
||||
* <p>
|
||||
* ThreadUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
|
||||
* {@code ThreadUtils.getAllThreads()}
|
||||
* </p>
|
||||
* <p>
|
||||
* This constructor is public to permit tools that require a JavaBean instance to operate.
|
||||
* </p>
|
||||
*/
|
||||
public ThreadUtils() {
|
||||
super();
|
||||
}
|
||||
|
||||
/**
|
||||
* A predicate for selecting threads.
|
||||
*/
|
||||
//if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
|
||||
public interface ThreadPredicate /*extends java.util.function.Predicate<Thread>*/{
|
||||
|
||||
/**
|
||||
* Evaluates this predicate on the given thread.
|
||||
* @param thread the thread
|
||||
* @return {@code true} if the thread matches the predicate, otherwise {@code false}
|
||||
*/
|
||||
boolean test(Thread thread);
|
||||
}
|
||||
|
||||
/**
|
||||
* A predicate for selecting threadgroups.
|
||||
*/
|
||||
//if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
|
||||
public interface ThreadGroupPredicate /*extends java.util.function.Predicate<ThreadGroup>*/{
|
||||
|
||||
/**
|
||||
* Evaluates this predicate on the given threadgroup.
|
||||
* @param threadGroup the threadgroup
|
||||
* @return {@code true} if the threadGroup matches the predicate, otherwise {@code false}
|
||||
*/
|
||||
boolean test(ThreadGroup threadGroup);
|
||||
}
|
||||
|
||||
/**
|
||||
* Predicate which always returns true.
|
||||
*/
|
||||
public static final AlwaysTruePredicate ALWAYS_TRUE_PREDICATE = new AlwaysTruePredicate();
|
||||
|
||||
/**
|
||||
* A predicate implementation which always returns true.
|
||||
*/
|
||||
private final static class AlwaysTruePredicate implements ThreadPredicate, ThreadGroupPredicate{
|
||||
|
||||
private AlwaysTruePredicate() {
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean test(final ThreadGroup threadGroup) {
|
||||
return true;
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean test(final Thread thread) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* A predicate implementation which matches a thread or threadgroup name.
|
||||
*/
|
||||
public static class NamePredicate implements ThreadPredicate, ThreadGroupPredicate {
|
||||
|
||||
private final String name;
|
||||
|
||||
/**
|
||||
* Predicate constructor
|
||||
*
|
||||
* @param name thread or threadgroup name
|
||||
* @throws IllegalArgumentException if the name is {@code null}
|
||||
*/
|
||||
public NamePredicate(final String name) {
|
||||
super();
|
||||
if (name == null) {
|
||||
throw new IllegalArgumentException("The name must not be null");
|
||||
}
|
||||
this.name = name;
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean test(final ThreadGroup threadGroup) {
|
||||
return threadGroup != null && threadGroup.getName().equals(name);
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean test(final Thread thread) {
|
||||
return thread != null && thread.getName().equals(name);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* A predicate implementation which matches a thread id.
|
||||
*/
|
||||
public static class ThreadIdPredicate implements ThreadPredicate {
|
||||
|
||||
private final long threadId;
|
||||
|
||||
/**
|
||||
* Predicate constructor
|
||||
*
|
||||
* @param threadId the threadId to match
|
||||
* @throws IllegalArgumentException if the threadId is zero or negative
|
||||
*/
|
||||
public ThreadIdPredicate(final long threadId) {
|
||||
super();
|
||||
if (threadId <= 0) {
|
||||
throw new IllegalArgumentException("The thread id must be greater than zero");
|
||||
}
|
||||
this.threadId = threadId;
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean test(final Thread thread) {
|
||||
return thread != null && thread.getId() == threadId;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Select all active threads which match the given predicate.
|
||||
*
|
||||
* @param predicate the predicate
|
||||
* @return An unmodifiable {@code Collection} of active threads matching the given predicate
|
||||
*
|
||||
* @throws IllegalArgumentException if the predicate is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> findThreads(final ThreadPredicate predicate){
|
||||
return findThreads(getSystemThreadGroup(), true, predicate);
|
||||
}
|
||||
|
||||
/**
|
||||
* Select all active threadgroups which match the given predicate.
|
||||
*
|
||||
* @param predicate the predicate
|
||||
* @return An unmodifiable {@code Collection} of active threadgroups matching the given predicate
|
||||
* @throws IllegalArgumentException if the predicate is null
|
||||
* @throws SecurityException
|
||||
* if the current thread cannot access the system thread group
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<ThreadGroup> findThreadGroups(final ThreadGroupPredicate predicate){
|
||||
return findThreadGroups(getSystemThreadGroup(), true, predicate);
|
||||
}
|
||||
|
||||
/**
|
||||
* Select all active threads which match the given predicate and which belongs to the given thread group (or one of its subgroups).
|
||||
*
|
||||
* @param group the thread group
|
||||
* @param recurse if {@code true} then evaluate the predicate recursively on all threads in all subgroups of the given group
|
||||
* @param predicate the predicate
|
||||
* @return An unmodifiable {@code Collection} of active threads which match the given predicate and which belongs to the given thread group
|
||||
* @throws IllegalArgumentException if the given group or predicate is null
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<Thread> findThreads(final ThreadGroup group, final boolean recurse, final ThreadPredicate predicate) {
|
||||
if (group == null) {
|
||||
throw new IllegalArgumentException("The group must not be null");
|
||||
}
|
||||
if (predicate == null) {
|
||||
throw new IllegalArgumentException("The predicate must not be null");
|
||||
}
|
||||
|
||||
int count = group.activeCount();
|
||||
Thread[] threads;
|
||||
do {
|
||||
threads = new Thread[count + (count / 2) + 1]; //slightly grow the array size
|
||||
count = group.enumerate(threads, recurse);
|
||||
//return value of enumerate() must be strictly less than the array size according to javadoc
|
||||
} while (count >= threads.length);
|
||||
|
||||
final List<Thread> result = new ArrayList<Thread>(count);
|
||||
for (int i = 0; i < count; ++i) {
|
||||
if (predicate.test(threads[i])) {
|
||||
result.add(threads[i]);
|
||||
}
|
||||
}
|
||||
return Collections.unmodifiableCollection(result);
|
||||
}
|
||||
|
||||
/**
|
||||
* Select all active threadgroups which match the given predicate and which is a subgroup of the given thread group (or one of its subgroups).
|
||||
*
|
||||
* @param group the thread group
|
||||
* @param recurse if {@code true} then evaluate the predicate recursively on all threadgroups in all subgroups of the given group
|
||||
* @param predicate the predicate
|
||||
* @return An unmodifiable {@code Collection} of active threadgroups which match the given predicate and which is a subgroup of the given thread group
|
||||
* @throws IllegalArgumentException if the given group or predicate is null
|
||||
* @throws SecurityException if the current thread cannot modify
|
||||
* thread groups from this thread's thread group up to the system thread group
|
||||
*/
|
||||
public static Collection<ThreadGroup> findThreadGroups(final ThreadGroup group, final boolean recurse, final ThreadGroupPredicate predicate){
|
||||
if (group == null) {
|
||||
throw new IllegalArgumentException("The group must not be null");
|
||||
}
|
||||
if (predicate == null) {
|
||||
throw new IllegalArgumentException("The predicate must not be null");
|
||||
}
|
||||
|
||||
int count = group.activeGroupCount();
|
||||
ThreadGroup[] threadGroups;
|
||||
do {
|
||||
threadGroups = new ThreadGroup[count + (count / 2) + 1]; //slightly grow the array size
|
||||
count = group.enumerate(threadGroups, recurse);
|
||||
//return value of enumerate() must be strictly less than the array size according to javadoc
|
||||
} while(count >= threadGroups.length);
|
||||
|
||||
final List<ThreadGroup> result = new ArrayList<ThreadGroup>(count);
|
||||
for(int i = 0; i < count; ++i) {
|
||||
if(predicate.test(threadGroups[i])) {
|
||||
result.add(threadGroups[i]);
|
||||
}
|
||||
}
|
||||
return Collections.unmodifiableCollection(result);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue