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Commit 2278952

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Java.EdgeJava.Edge
Java.Edge
authored and
Java.Edge
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2 parents da6425e + 3df0e54 commit 2278952

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6 files changed

+228
-0
lines changed

6 files changed

+228
-0
lines changed
Lines changed: 25 additions & 0 deletions
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public class LockSupportBlockerTest {
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public static void main(String[] args) {
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Thread t3 = new Thread(() -> {
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Thread.currentThread().setName("t3");
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System.out.println(Thread.currentThread().getName() + " park 5 seconds");
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//park 5 seconds, set blocker
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Object blocker = new String("sss");
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LockSupport.parkUntil(blocker, System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS));
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System.out.println(Thread.currentThread().getName() + " after park");
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});
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t3.start();
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try {
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Object t3_blocker = null;
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while (t3_blocker == null) {
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t3_blocker = LockSupport.getBlocker(t3);
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TimeUnit.MILLISECONDS.sleep(10);
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}
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System.out.println("t3 blocker is :" + t3_blocker);
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t3.join();
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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}
Lines changed: 48 additions & 0 deletions
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public class LockSupportExam {
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public static void main(String[] args) {
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Thread t1 = new Thread() {
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@Override
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public void run() {
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Thread.currentThread().setName("t1");
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System.out.println(Thread.currentThread().getName() + " before park");
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//park 100 seconds
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LockSupport.parkNanos(TimeUnit.NANOSECONDS.convert(100, TimeUnit.SECONDS));
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System.out.println(Thread.currentThread().getName() + " after park");
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}
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};
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Thread t2 = new Thread() {
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@Override
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public void run() {
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try {
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Thread.currentThread().setName("t2");
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TimeUnit.SECONDS.sleep(1);
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System.out.println(Thread.currentThread().getName() + " unpark t1");
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LockSupport.unpark(t1);
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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};
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Thread t3 = new Thread() {
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@Override
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public void run() {
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Thread.currentThread().setName("t3");
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System.out.println(Thread.currentThread().getName() + " park 5 seconds");
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//park 5 seconds
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LockSupport.parkUntil(System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5,TimeUnit.SECONDS));
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System.out.println(Thread.currentThread().getName() + " after park");
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}
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};
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t1.start();
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t2.start();
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t3.start();
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try {
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t1.join();
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t2.join();
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t3.join();
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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}
Lines changed: 52 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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public class UnsafeTest {
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public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
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Field f = Unsafe.class.getDeclaredField("theUnsafe");
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f.setAccessible(true);
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Unsafe unsafe = (Unsafe) f.get(null);
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Thread t1 = new Thread() {
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@Override
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public void run() {
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Thread.currentThread().setName("t1");
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System.out.println(Thread.currentThread().getName() + " before park");
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//park 100 seconds
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unsafe.park(false, TimeUnit.NANOSECONDS.convert(100, TimeUnit.SECONDS));
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System.out.println(Thread.currentThread().getName() + " after park");
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}
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};
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Thread t2 = new Thread() {
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@Override
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public void run() {
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try {
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Thread.currentThread().setName("t2");
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TimeUnit.SECONDS.sleep(1);
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System.out.println(Thread.currentThread().getName() + " unpark t1");
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unsafe.unpark(t1);
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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};
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Thread t3 = new Thread() {
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@Override
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public void run() {
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Thread.currentThread().setName("t3");
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System.out.println(Thread.currentThread().getName() + " park 5 seconds");
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//park 5 seconds
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unsafe.park(true, System.currentTimeMillis() + TimeUnit.MILLISECONDS.convert(5,TimeUnit.SECONDS));
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System.out.println(Thread.currentThread().getName() + " after park");
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}
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};
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t1.start();
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t2.start();
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t3.start();
44+
try {
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t1.join();
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t2.join();
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t3.join();
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} catch (InterruptedException e) {
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e.printStackTrace();
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}
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}
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}
Lines changed: 70 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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public class SimpleLock {
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private static class Sync extends AbstractQueuedSynchronizer {
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@Override
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protected boolean tryAcquire(int ignore) {
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return compareAndSetState(0, 1);
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}
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@Override
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protected boolean tryRelease(int ignore) {
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setState(0);
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return true;
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}
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14+
protected Sync() {
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super();
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}
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}
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private final Sync sync = new Sync();
20+
21+
public void lock() {
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sync.acquire(1);
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}
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25+
public void unlock() {
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sync.release(1);
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}
28+
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private static class MyThread extends Thread {
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private final String name;
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private final SimpleLock lock;
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33+
private MyThread(String name, SimpleLock lock) {
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this.name = name;
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this.lock = lock;
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}
37+
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@Override
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public void run() {
40+
try {
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lock.lock();
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System.out.println(name + " get the lock");
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TimeUnit.SECONDS.sleep(2);
44+
} catch (InterruptedException e) {
45+
e.printStackTrace();
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} finally {
47+
lock.unlock();
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System.out.println(name + " release the lock");
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}
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}
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}
52+
53+
public static void main(String[] args) {
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final SimpleLock mutex = new SimpleLock();
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MyThread t1 = new MyThread("t1", mutex);
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MyThread t2 = new MyThread("t2", mutex);
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MyThread t3 = new MyThread("t3", mutex);
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t1.start();
59+
t2.start();
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t3.start();
61+
try {
62+
t1.join();
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t2.join();
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t3.join();
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} catch (InterruptedException e) {
66+
e.printStackTrace();
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}
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System.out.println("main thread exit!");
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}
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}
Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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1+
import java.util.concurrent.atomic.AtomicInteger;
2+
3+
public class TicketLock {
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private AtomicInteger serviceNum = new AtomicInteger(); // 服务号
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private AtomicInteger ticketNum = new AtomicInteger(); // 排队号
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7+
public int lock() {
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// 首先原子性地获得一个排队号
9+
int myTicketNum = ticketNum.getAndIncrement();
10+
11+
// 只要当前服务号不是自己的就不断轮询
12+
while (serviceNum.get() != myTicketNum) {
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}
14+
15+
return myTicketNum;
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}
17+
18+
public void unlock(int myTicket) {
19+
// 只有当前线程拥有者才能释放锁
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int next = myTicket + 1;
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serviceNum.compareAndSet(myTicket, next);
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}
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}

‎concurrency/src/main/main.iml

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -7,5 +7,15 @@
77
</content>
88
<orderEntry type="inheritedJdk" />
99
<orderEntry type="sourceFolder" forTests="false" />
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<orderEntry type="module-library">
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<library name="JUnit4">
12+
<CLASSES>
13+
<root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.12/junit-4.12.jar!/" />
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<root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
15+
</CLASSES>
16+
<JAVADOC />
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<SOURCES />
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</library>
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</orderEntry>
1020
</component>
1121
</module>

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