Java Code Examples for java.util.concurrent.ConcurrentHashMap#forEach()

The following examples show how to use java.util.concurrent.ConcurrentHashMap#forEach() . These examples are extracted from open source projects. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may want to check out the right sidebar which shows the related API usage.
Example 1
private void getConnections(ChannelHandlerContext ctx, ConcurrentHashMap<String,ClientConnection> connectionFactory) {
    ArrayList<ClientConnectionVO> vos = new ArrayList<>();
    if(null !=connectionFactory && !connectionFactory.isEmpty()){
        connectionFactory.forEach((k,v)->{
            ClientConnectionVO  vo=new ClientConnectionVO();
            vo.setClientId(v.getClientId());
            vo.setUsername(v.getUsername());
            vo.setIp(v.getIp());
            vo.setPort(v.getPort());
            vo.setConnectedDate(v.getConnectedDate());
            vo.setProtocolVersion(v.getProtocolVersion());
            vo.setPassword(v.getPassword());
            vos.add(vo);
        });
    }
    // 1.设置响应
    Result result= new Result<Object>().ok(vos);
    FullHttpResponse resp = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,
            HttpResponseStatus.OK,
            Unpooled.copiedBuffer(JSONObject.toJSONString(result), CharsetUtil.UTF_8));
    resp.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/html; charset=UTF-8");
    // 2.发送
    // 注意必须在使用完之后,close channel
    ctx.writeAndFlush(resp).addListener(ChannelFutureListener.CLOSE);

}
 
Example 2
public static  void  sendOffLineGroupMessage(String groupId){
    ClientGroup clientGroup = group.get(groupId);
    if(clientGroup!=null){
        ConcurrentHashMap<String, Channel> clients = clientGroup.subOfflineClients;
        clients.forEach((K,V)->{
            MqttFixedHeader pubFixedHeader = new MqttFixedHeader(MqttMessageType.PUBLISH, false,
                    MqttQoS.AT_MOST_ONCE, false, 0);
            MqttPublishVariableHeader publishVariableHeader=new MqttPublishVariableHeader(clientGroup.offLineTopic,1);
            ByteBuf payload = Unpooled.buffer(200);
            payload.writeBytes("下线消息".getBytes());
            MqttPublishMessage pubMsg=new MqttPublishMessage(pubFixedHeader,publishVariableHeader,payload);
            V.writeAndFlush(pubMsg);
            System.out.println("=============群发下线消息===============");
        });
    }



}
 
Example 3
public static void main(String[] args) {
    ConcurrentHashMap<Integer, UUID> concurrentHashMap = new ConcurrentHashMap<>();

    for (int i = 0; i < 100; i++) {
        concurrentHashMap.put(i, UUID.randomUUID());
    }

    int threshold = 1;

    concurrentHashMap.forEachValue(threshold, System.out::println);

    concurrentHashMap.forEach((id, uuid) -> {
        if (id % 10 == 0) {
            System.out.println(String.format("%s: %s", id, uuid));
        }
    });

    UUID searchResult = concurrentHashMap.search(threshold, (id, uuid) -> {
        if (String.valueOf(uuid).startsWith(String.valueOf(id))) {
            return uuid;
        }
        return null;
    });

    System.out.println(searchResult);
}
 
Example 4
Source Project: java8-tutorial   File: Concurrency1.java    License: MIT License 6 votes vote down vote up
public static void main(String[] args) {
    ConcurrentHashMap<Integer, UUID> concurrentHashMap = new ConcurrentHashMap<>();

    for (int i = 0; i < 100; i++) {
        concurrentHashMap.put(i, UUID.randomUUID());
    }

    int threshold = 1;

    concurrentHashMap.forEachValue(threshold, System.out::println);

    concurrentHashMap.forEach((id, uuid) -> {
        if (id % 10 == 0) {
            System.out.println(String.format("%s: %s", id, uuid));
        }
    });

    UUID searchResult = concurrentHashMap.search(threshold, (id, uuid) -> {
        if (String.valueOf(uuid).startsWith(String.valueOf(id))) {
            return uuid;
        }
        return null;
    });

    System.out.println(searchResult);
}
 
Example 5
Source Project: Java-Coding-Problems   File: Main.java    License: MIT License 5 votes vote down vote up
public static void main(String[] args) {

        ConcurrentHashMap<Integer, Integer> map = new ConcurrentHashMap<>();
        map.put(1, 1);
        map.put(2, 1);
        map.put(3, 1);
        map.put(4, 1);
        map.put(5, 1);
        map.put(6, 1);

        System.out.println("Map: \n" + map);

        System.out.println("\nMap displayed via forEach():");
        map.forEach(2, (k, v) -> System.out.println("key: " + k + ", Value: " + v));

        System.out.println("\nMap displayed via forEach() after incrementing each value with 1:");
        map.forEach(2, (k, v) -> v = v + 1, v -> System.out.println("Value: " + v));

        System.out.println("\nMap displayed via forEachEntry():");
        map.forEachEntry(2, (e) -> System.out.println("key: " + e.getKey() + ", Value: " + e.getValue()));

        System.out.println("\nCheck if key=value via forEachEntry():");
        map.forEachEntry(2, (e) -> Objects.equals(e.getKey(), e.getValue()), System.out::println);

        System.out.println("\nDisplay keys via forEachKey():");
        map.forEachKey(2, System.out::println);

        System.out.println("\nKeys displayed via forEachKey() after incrementing each key with 1:");
        map.forEachKey(2, (k) -> k = k + 1, System.out::println);

        System.out.println("\nDisplay values via forEachValue():");
        map.forEachValue(2, System.out::println);

        System.out.println("\nKeys displayed via forEachValue() after incrementing each value with 1:");
        map.forEachValue(2, (v) -> v = v + 1, System.out::println);
    }
 
Example 6
private static void testForEach() {
        ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
        map.putIfAbsent("foo", "bar");
        map.putIfAbsent("han", "solo");
        map.putIfAbsent("r2", "d2");
        map.putIfAbsent("c3", "p0");

        map.forEach(1, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));
//        map.forEach(5, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));

        System.out.println(map.mappingCount());
    }
 
Example 7
private static void testForEach() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.putIfAbsent("foo", "bar");
    map.putIfAbsent("han", "solo");
    map.putIfAbsent("r2", "d2");
    map.putIfAbsent("c3", "p0");

    map.forEach(1, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value,
        Thread.currentThread().getName()));
    // map.forEach(5, (key, value) -> System.out.printf("key: %s; value: %s; thread:
    // %s\n", key, value,
    // Thread.currentThread().getName()));

    System.out.println(map.mappingCount());
}
 
Example 8
/**
 * Example using a Cleaner to remove WeakKey references from a Map.
 */
@Test
void testWeakKey() {
    ConcurrentHashMap<WeakKey<String>, String> map = new ConcurrentHashMap<>();
    Cleaner cleaner = Cleaner.create();
    String key = new String("foo");  //  ensure it is not interned
    String data = "bar";

    map.put(new WeakKey<>(key, cleaner, map), data);

    WeakKey<String> k2 = new WeakKey<>(key, cleaner, map);

    Assert.assertEquals(map.get(k2), data, "value should be found in the map");
    key = null;
    System.gc();
    Assert.assertNotEquals(map.get(k2), data, "value should not be found in the map");

    final long CYCLE_MAX = Utils.adjustTimeout(30L);
    for (int i = 1; map.size() > 0 && i < CYCLE_MAX; i++) {
        map.forEach( (k, v) -> System.out.printf("    k: %s, v: %s%n", k, v));
        try {
            Thread.sleep(10L);
        } catch (InterruptedException ie) {}
    }
    Assert.assertEquals(map.size(), 0, "Expected map to be empty;");
    cleaner = null;
}
 
Example 9
/**
 * forEachSequentially traverses all mappings
 */
public void testForEachSequentially() {
    LongAdder adder = new LongAdder();
    ConcurrentHashMap<Long, Long> m = longMap();
    m.forEach(Long.MAX_VALUE, (Long x, Long y) -> adder.add(x.longValue() + y.longValue()));
    assertEquals(adder.sum(), 3 * SIZE * (SIZE - 1) / 2);
}
 
Example 10
/**
 * forEachInParallel traverses all mappings
 */
public void testForEachInParallel() {
    LongAdder adder = new LongAdder();
    ConcurrentHashMap<Long, Long> m = longMap();
    m.forEach(1L, (Long x, Long y) -> adder.add(x.longValue() + y.longValue()));
    assertEquals(adder.sum(), 3 * SIZE * (SIZE - 1) / 2);
}
 
Example 11
Source Project: j2objc   File: ConcurrentHashMap8Test.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * forEachSequentially traverses all mappings
 */
public void testForEachSequentially() {
    LongAdder adder = new LongAdder();
    ConcurrentHashMap<Long, Long> m = longMap();
    m.forEach(Long.MAX_VALUE, (Long x, Long y) -> adder.add(x.longValue() + y.longValue()));
    assertEquals(adder.sum(), 3 * SIZE * (SIZE - 1) / 2);
}
 
Example 12
Source Project: j2objc   File: ConcurrentHashMap8Test.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * forEachInParallel traverses all mappings
 */
public void testForEachInParallel() {
    LongAdder adder = new LongAdder();
    ConcurrentHashMap<Long, Long> m = longMap();
    m.forEach(1L, (Long x, Long y) -> adder.add(x.longValue() + y.longValue()));
    assertEquals(adder.sum(), 3 * SIZE * (SIZE - 1) / 2);
}
 
Example 13
Source Project: java8-tutorial   File: ConcurrentHashMap1.java    License: MIT License 5 votes vote down vote up
private static void testForEach() {
        ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
        map.putIfAbsent("foo", "bar");
        map.putIfAbsent("han", "solo");
        map.putIfAbsent("r2", "d2");
        map.putIfAbsent("c3", "p0");

        map.forEach(1, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));
//        map.forEach(5, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));

        System.out.println(map.mappingCount());
    }
 
Example 14
Source Project: elasticactors   File: ShardedScheduler.java    License: Apache License 2.0 5 votes vote down vote up
@Override
public void unregisterShard(ShardKey shardKey) {
    ConcurrentHashMap<ScheduledMessageKey, ScheduledFuture<?>> scheduledFuturesForShard =
            scheduledFutures.remove(shardKey);
    if (scheduledFuturesForShard != null) {
        scheduledFuturesForShard.forEach((k, scheduledFuture) -> scheduledFuture.cancel(false));
    }
}
 
Example 15
Source Project: java-tutorial   File: ConcurrentMapTest.java    License: MIT License 4 votes vote down vote up
/**
 * ConcurrentMap接口继承自Map接口,并定义了最实用的并发集合类型之一。
 * Java8通过将新的方法添加到这个接口,引入了函数式编程。
 * ConcurrentHashMap 是无序的
 */
public void concurrentMapDemo() {
    ConcurrentHashMap<String, String> map = new ConcurrentHashMap<>();
    map.put("foo", "bar");
    map.put("han", "solo");
    map.put("r2", "d2");
    map.put("c3", "p0");

    // 方法可以并行迭代映射中的键值对
    map.forEach(1, (k, v) ->
            System.out.printf("key: %s; value: %s; thread: %s\n",
                    k, v, Thread.currentThread().getName()));

    System.out.println("\n");
    // search 只要返回了非空的结果,就不会往下搜索了
    String result = map.search(1, (k, v) -> {
                System.out.println(Thread.currentThread().getName());
                if ("foo".equals(k)) {
                    return v;
                }
                return null;
            }
    );

    System.out.println("Result: " + result);

    System.out.println("\n");
    String result1 = map.search(1, (k, v) -> {
                System.out.println(Thread.currentThread().getName());
                if (v.length() > 3) {
                    return v;
                }
                return null;
            }
    );

    System.out.println("Result: " + result1);

    System.out.println("\n");
    String result2 = map.reduce(1,
            (k, v) -> {
                System.out.println("Transform: " + Thread.currentThread().getName());
                return k + "=" + v;
            },
            (s1, s2) -> {
                System.out.println("Reduce: " + Thread.currentThread().getName());
                return s1 + ", " + s2;
            }
    );
    System.out.println("Result: " + result2);
}
 
Example 16
/**
 * Test destroy of processes.
 * A JavaChild is started and it starts three children.
 * Each one is then checked to be alive and listed by descendants
 * and forcibly destroyed.
 * After they exit they should no longer be listed by descendants.
 */
@Test
public static void test3() {
    ConcurrentHashMap<ProcessHandle, ProcessHandle> processes = new ConcurrentHashMap<>();

    try {
        ProcessHandle self = ProcessHandle.current();

        JavaChild p1 = JavaChild.spawnJavaChild("stdin");
        ProcessHandle p1Handle = p1.toHandle();
        printf(" p1: %s%n", p1.pid());

        int newChildren = 3;
        CountDownLatch spawnCount = new CountDownLatch(newChildren);
        // Spawn children and have them wait
        p1.sendAction("spawn", newChildren, "stdin");

        // Gather the PIDs from the output of the spawning process
        p1.forEachOutputLine((s) -> {
            String[] split = s.trim().split(" ");
            if (split.length == 3 && split[1].equals("spawn")) {
                Long child = Long.valueOf(split[2]);
                Long parent = Long.valueOf(split[0].split(":")[0]);
                processes.put(ProcessHandle.of(child).get(), ProcessHandle.of(parent).get());
                spawnCount.countDown();
            }
        });

        // Wait for all the subprocesses to be listed as started
        Assert.assertTrue(spawnCount.await(Utils.adjustTimeout(30L), TimeUnit.SECONDS),
                "Timeout waiting for processes to start");

        // Debugging; list descendants that are not expected in processes
        List<ProcessHandle> descendants = ProcessUtil.getDescendants(p1Handle);
        long count = descendants.stream()
                .filter(ph -> !processes.containsKey(ph))
                .count();
        if (count > 0) {
            descendants.stream()
                .filter(ph -> !processes.containsKey(ph))
                .forEach(ph1 -> ProcessUtil.printProcess(ph1, "Extra process: "));
            ProcessUtil.logTaskList();
            Assert.assertEquals(0, count, "Extra processes in descendants");
        }

        // Verify that all spawned children are alive, show up in the descendants list
        // then destroy them
        processes.forEach((p, parent) -> {
            Assert.assertEquals(p.isAlive(), true, "Child should be alive: " + p);
            Assert.assertTrue(descendants.contains(p), "Spawned child should be listed in descendants: " + p);
            p.destroyForcibly();
        });
        Assert.assertEquals(processes.size(), newChildren, "Wrong number of children");

        // Wait for each of the processes to exit
        processes.forEach((p, parent) ->  {
            for (long retries = Utils.adjustTimeout(100L); retries > 0 ; retries--) {
                if (!p.isAlive()) {
                    return;                 // not alive, go on to the next
                }
                // Wait a bit and retry
                try {
                    Thread.sleep(100L);
                } catch (InterruptedException ie) {
                    // try again
                }
            }
            printf("Timeout waiting for exit of pid %s, parent: %s, info: %s%n",
                    p, parent, p.info());
            Assert.fail("Process still alive: " + p);
        });
        p1.destroyForcibly();
        p1.waitFor();

        // Verify that none of the spawned children are still listed by descendants
        List<ProcessHandle> remaining = getDescendants(self);
        Assert.assertFalse(remaining.remove(p1Handle), "Child p1 should have exited");
        remaining = remaining.stream().filter(processes::containsKey).collect(Collectors.toList());
        Assert.assertEquals(remaining.size(), 0, "Subprocess(es) should have exited: " + remaining);

    } catch (IOException ioe) {
        Assert.fail("Spawn of subprocess failed", ioe);
    } catch (InterruptedException inte) {
        Assert.fail("InterruptedException", inte);
    } finally {
        processes.forEach((p, parent) -> {
            if (p.isAlive()) {
                ProcessUtil.printProcess(p);
                p.destroyForcibly();
            }
        });
    }
}
 
Example 17
/**
 * A test for scale; launch a large number (14) of subprocesses.
 */
@Test
public static void test5() {
    ConcurrentHashMap<ProcessHandle, ProcessHandle> processes = new ConcurrentHashMap<>();

    int factor = 2;
    JavaChild p1 = null;
    Instant start = Instant.now();
    try {
        p1 = JavaChild.spawnJavaChild("stdin");
        ProcessHandle p1Handle = p1.toHandle();

        printf("Spawning %d x %d x %d processes, pid: %d%n",
                factor, factor, factor, p1.pid());

        // Start the first tier of subprocesses
        p1.sendAction("spawn", factor, "stdin");

        // Start the second tier of subprocesses
        p1.sendAction("child", "spawn", factor, "stdin");

        // Start the third tier of subprocesses
        p1.sendAction("child", "child", "spawn", factor, "stdin");

        int newChildren = factor * (1 + factor * (1 + factor));
        CountDownLatch spawnCount = new CountDownLatch(newChildren);

        // Gather the PIDs from the output of the spawning process
        p1.forEachOutputLine((s) -> {
            String[] split = s.trim().split(" ");
            if (split.length == 3 && split[1].equals("spawn")) {
                Long child = Long.valueOf(split[2]);
                Long parent = Long.valueOf(split[0].split(":")[0]);
                processes.put(ProcessHandle.of(child).get(), ProcessHandle.of(parent).get());
                spawnCount.countDown();
            }
        });

        // Wait for all the subprocesses to be listed as started
        Assert.assertTrue(spawnCount.await(Utils.adjustTimeout(30L), TimeUnit.SECONDS),
                "Timeout waiting for processes to start");

        // Debugging; list descendants that are not expected in processes
        List<ProcessHandle> descendants = ProcessUtil.getDescendants(p1Handle);
        long count = descendants.stream()
                .filter(ph -> !processes.containsKey(ph))
                .count();
        if (count > 0) {
            descendants.stream()
                .filter(ph -> !processes.containsKey(ph))
                .forEach(ph1 -> ProcessUtil.printProcess(ph1, "Extra process: "));
            ProcessUtil.logTaskList();
            Assert.assertEquals(0, count, "Extra processes in descendants");
        }

        Assert.assertEquals(getChildren(p1Handle).size(),
                factor, "expected direct children");
        count = getDescendants(p1Handle).size();
        long totalChildren = factor * factor * factor + factor * factor + factor;
        Assert.assertTrue(count >= totalChildren,
                "expected at least " + totalChildren + ", actual: " + count);

        List<ProcessHandle> subprocesses = getDescendants(p1Handle);
        printf(" descendants:  %s%n",
                subprocesses.stream().map(p -> p.pid())
                .collect(Collectors.toList()));

        p1.getOutputStream().close();  // Close stdin for the controlling p1
        p1.waitFor();
    } catch (InterruptedException | IOException ex) {
        Assert.fail("Unexpected Exception", ex);
    } finally {
        printf("Duration: %s%n", Duration.between(start, Instant.now()));
        if (p1 != null) {
            p1.destroyForcibly();
        }
        processes.forEach((p, parent) -> {
            if (p.isAlive()) {
                ProcessUtil.printProcess(p, "Process Cleanup: ");
                p.destroyForcibly();
            }
        });
    }
}