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| 1 | +packagecom.winterbe.java8.samples.concurrent; |
| 2 | + |
| 3 | +importjava.util.HashMap; |
| 4 | +importjava.util.Map; |
| 5 | +importjava.util.concurrent.ExecutorService; |
| 6 | +importjava.util.concurrent.Executors; |
| 7 | +importjava.util.concurrent.TimeUnit; |
| 8 | +importjava.util.concurrent.locks.ReadWriteLock; |
| 9 | +importjava.util.concurrent.locks.ReentrantReadWriteLock; |
| 10 | + |
| 11 | +/** |
| 12 | + * @author Benjamin Winterberg |
| 13 | + */ |
| 14 | +publicclassLock3 { |
| 15 | + |
| 16 | +publicstaticvoidmain(String[]args) { |
| 17 | +ExecutorServiceexecutor =Executors.newFixedThreadPool(2); |
| 18 | + |
| 19 | +Map<String,String>map =newHashMap<>(); |
| 20 | + |
| 21 | +ReadWriteLocklock =newReentrantReadWriteLock(); |
| 22 | + |
| 23 | +executor.submit(() -> { |
| 24 | +lock.writeLock().lock(); |
| 25 | +try { |
| 26 | +TimeUnit.SECONDS.sleep(1); |
| 27 | +map.put("foo","bar"); |
| 28 | + } |
| 29 | +catch (InterruptedExceptione) { |
| 30 | +thrownewIllegalStateException(e); |
| 31 | + } |
| 32 | +finally { |
| 33 | +lock.writeLock().unlock(); |
| 34 | + } |
| 35 | + }); |
| 36 | + |
| 37 | +executor.submit(() -> { |
| 38 | +lock.readLock().lock(); |
| 39 | +try { |
| 40 | +Stringfoo =map.get("foo"); |
| 41 | +System.out.println(foo); |
| 42 | +TimeUnit.SECONDS.sleep(1); |
| 43 | + } |
| 44 | +catch (InterruptedExceptione) { |
| 45 | +thrownewIllegalStateException(e); |
| 46 | + } |
| 47 | +finally { |
| 48 | +lock.readLock().unlock(); |
| 49 | + } |
| 50 | + }); |
| 51 | + |
| 52 | +executor.submit(() -> { |
| 53 | +lock.readLock().lock(); |
| 54 | +try { |
| 55 | +Stringfoo =map.get("foo"); |
| 56 | +System.out.println(foo); |
| 57 | +TimeUnit.SECONDS.sleep(1); |
| 58 | + } |
| 59 | +catch (InterruptedExceptione) { |
| 60 | +thrownewIllegalStateException(e); |
| 61 | + } |
| 62 | +finally { |
| 63 | +lock.readLock().unlock(); |
| 64 | + } |
| 65 | + }); |
| 66 | + |
| 67 | +ConcurrentUtils.stop(executor); |
| 68 | + } |
| 69 | + |
| 70 | +} |