diff --git a/src/main/java/org/apache/commons/lang3/ThreadUtils.java b/src/main/java/org/apache/commons/lang3/ThreadUtils.java
index 1174ff7ad..15f0c5c05 100644
--- a/src/main/java/org/apache/commons/lang3/ThreadUtils.java
+++ b/src/main/java/org/apache/commons/lang3/ThreadUtils.java
@@ -1,466 +1,460 @@
-/*
- * 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;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-
-/**
- *
- * Helpers for {@code java.lang.Thread} and {@code java.lang.ThreadGroup}.
- *
- *
- * #ThreadSafe#
- *
- *
- * @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 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 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 threadGroups = findThreadGroups(new NamePredicate(threadGroupName));
-
- if(threadGroups.isEmpty()) {
- return Collections.emptyList();
- }
-
- final Collection result = new ArrayList();
- 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 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 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 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 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 result = findThreads(new ThreadIdPredicate(threadId));
-
- if(result.isEmpty()) {
- return null;
- } else {
- return result.iterator().next();
- }
-
- }
-
- /**
- *
- * ThreadUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
- * {@code ThreadUtils.getAllThreads()}
- *
- *
- * This constructor is public to permit tools that require a JavaBean instance to operate.
- *
- */
- 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*/{
-
- /**
- * 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*/{
-
- /**
- * 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 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 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 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 result = new ArrayList(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 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 result = new ArrayList(count);
- for(int i = 0; i < count; ++i) {
- if(predicate.test(threadGroups[i])) {
- result.add(threadGroups[i]);
- }
- }
- return Collections.unmodifiableCollection(result);
- }
-}
+/*
+ * 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;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ *
+ * Helpers for {@code java.lang.Thread} and {@code java.lang.ThreadGroup}.
+ *
+ *
+ * #ThreadSafe#
+ *
+ *
+ * @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 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 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 threadGroups = findThreadGroups(new NamePredicate(threadGroupName));
+
+ if(threadGroups.isEmpty()) {
+ return Collections.emptyList();
+ }
+
+ final Collection result = new ArrayList();
+ 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 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 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 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 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 result = findThreads(new ThreadIdPredicate(threadId));
+ return result.isEmpty() ? null : result.iterator().next();
+ }
+
+ /**
+ *
+ * ThreadUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
+ * {@code ThreadUtils.getAllThreads()}
+ *
+ *
+ * This constructor is public to permit tools that require a JavaBean instance to operate.
+ *
+ */
+ 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*/{
+
+ /**
+ * 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*/{
+
+ /**
+ * 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 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 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 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 result = new ArrayList(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 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 result = new ArrayList(count);
+ for(int i = 0; i < count; ++i) {
+ if(predicate.test(threadGroups[i])) {
+ result.add(threadGroups[i]);
+ }
+ }
+ return Collections.unmodifiableCollection(result);
+ }
+}