Java Map.merge方法代碼示例

import java.util.Map; //導入方法依賴的package包/類
@Test
public void testMerge() {
  Map<String, UrlItem> map = new HashMap<>();

  UrlItem item1 = new UrlItem("abc");
  UrlItem item2 = new UrlItem("abc");

  RsMd rsmd1 = new RsMd()
    .withDateTime(ZonedDateTime.parse("2000-01-01T00:00:00.000Z").withZoneSameInstant(ZoneOffset.UTC));
  item1.withMetadata(rsmd1);

  RsMd rsmd2 = new RsMd()
    .withDateTime(ZonedDateTime.parse("2000-01-01T00:00:01.000Z").withZoneSameInstant(ZoneOffset.UTC));
  item2.withMetadata(rsmd2);


  map.merge("abc", item1, UrlItem::latest);
  assertThat(map.get("abc"), equalTo(item1));

  map.merge("abc", item2, UrlItem::latest);
  assertThat(map.get("abc"), equalTo(item2));

  map.merge("abc", item1, UrlItem::latest);
  assertThat(map.get("abc"), equalTo(item2));

}
 

import java.util.Map; //導入方法依賴的package包/類
@Override
public boolean checkPermutation(final String a, final String b) {
    int l = a.length();

    if (l == b.length()) {
        Map<Character, Integer> charMapA = new HashMap<>();
        Map<Character, Integer> charMapB = new HashMap<>();

        for (int i = 0; i < l; i++) {
            charMapA.merge(a.charAt(i), 1, (x, y) -> x + 1);
            charMapB.merge(b.charAt(i), 1, (x, y) -> x + 1);
        }

        return charMapA.equals(charMapB);
    } else {
        return false;
    }
}
 

import java.util.Map; //導入方法依賴的package包/類
@Override
public boolean isPalindromePermutation(final String input) {
    Map<Character, Integer> charCountMap = new HashMap<>();

    for (Character c : input.toCharArray()) {
        charCountMap.merge(c, 1, (a, b) -> a + 1);
    }

    boolean oddFound = false;
    for (Map.Entry<Character, Integer> e : charCountMap.entrySet()) {
        if (charCountMap.get(e.getKey()) % 2 != 0) {
            if (oddFound) {
                return false;
            }

            oddFound = true;
        }
    }

    return true;
}
 

import java.util.Map; //導入方法依賴的package包/類
public Map<String, Boolean> viewRemoteClusterStatus() {
  if (mapOfGatewaySenders.values().size() > 0) {
    Map<String, Boolean> senderMap = new HashMap<String, Boolean>();
    Iterator<GatewaySenderMXBean> it = mapOfGatewaySenders.values().iterator();
    while (it.hasNext()) {
      GatewaySenderMXBean bean = it.next();
      Integer dsId = bean.getRemoteDSId();
      if (dsId != null) {
        senderMap.merge(dsId.toString(), bean.isRunning(), Boolean::logicalAnd);
      }
    }

    return senderMap;
  }

  return Collections.emptyMap();
}
 

import java.util.Map; //導入方法依賴的package包/類
static public Map<String, Integer>
getRegionDistribution(TiSession session, String databaseName, String tableName) {
  requireNonNull(session, "session is null");
  requireNonNull(databaseName, "databaseName is null");
  requireNonNull(tableName, "tableName is null");
  TiTableInfo table = session.getCatalog().getTable(databaseName, tableName);
  requireNonNull(table, String.format("Table not found %s.%s", databaseName, tableName));
  ScanBuilder builder = new ScanBuilder();
  ScanPlan scanPlan = builder.buildScan(ImmutableList.of(), table);
  List<RegionTask> tasks = RangeSplitter
      .newSplitter(session.getRegionManager())
      .splitRangeByRegion(scanPlan.getKeyRanges());
  Map<String, Integer> regionMap = new HashMap<>();
  for (RegionTask task : tasks) {
    regionMap.merge(task.getHost() + "_" + task.getStore().getId(), 1, Integer::sum);
  }
  return regionMap;
}
 

import java.util.Map; //導入方法依賴的package包/類
/**
 * Creates and returns a "report" of (currently) tracked but not (yet) closed
 * instances.
 *
 * @return Set of CloseTrackedRegistryReportEntry, of which each the stack trace
 *         element identifies a unique allocation context (or an empty List if
 *         debugContextEnabled is false), and value is the number of open
 *         instances created at that place in the code.
 */
public Set<CloseTrackedRegistryReportEntry<T>> getAllUnique() {
    Map<List<StackTraceElement>, Long> map = new HashMap<>();
    Set<CloseTracked<T>> copyOfTracked = new HashSet<>(tracked);
    for (CloseTracked<T> closeTracked : copyOfTracked) {
        final StackTraceElement[] stackTraceArray = closeTracked.getAllocationContextStackTrace();
        List<StackTraceElement> stackTraceElements =
                stackTraceArray != null ? Arrays.asList(stackTraceArray) : Collections.emptyList();
        map.merge(stackTraceElements, 1L, (oldValue, value) -> oldValue + 1);
    }

    Set<CloseTrackedRegistryReportEntry<T>> report = new HashSet<>();
    map.forEach((stackTraceElements, number) -> {
        copyOfTracked.stream().filter(closeTracked -> {
            StackTraceElement[] closeTrackedStackTraceArray = closeTracked.getAllocationContextStackTrace();
            List<StackTraceElement> closeTrackedStackTraceElements =
                    closeTrackedStackTraceArray != null ? asList(closeTrackedStackTraceArray) : emptyList();
            return closeTrackedStackTraceElements.equals(stackTraceElements);
        }).findAny().ifPresent(exampleCloseTracked -> {
            report.add(new CloseTrackedRegistryReportEntry<>(exampleCloseTracked, number, stackTraceElements));
        });
    });
    return report;
}
 

import java.util.Map; //導入方法依賴的package包/類
/**
 * A helper function to get the number of leader partitions for each topic on each broker. It is useful to
 * derive the partition level IO from the topic level IO on a broker.
 * TODO: create open source KIP to provide per partition IO metrics.
 */
private Map<Integer, Map<String, Integer>> leaderDistributionStats(Cluster cluster) {
  Map<Integer, Map<String, Integer>> stats = new HashMap<>();
  for (Node node : cluster.nodes()) {
    Map<String, Integer> numLeadersByTopic = new HashMap<>();
    stats.put(node.id(), numLeadersByTopic);
    for (PartitionInfo partitionInfo : cluster.partitionsForNode(node.id())) {
      numLeadersByTopic.merge(partitionInfo.topic(), 1, (v0, v1) -> v0 + v1);
    }
  }
  return stats;
}
 

import java.util.Map; //導入方法依賴的package包/類
/**
 * Recursive function to walk up each iteration of time intervals until the biggest calculating the
 * expected count for each interval along the way
 */
private void addExpectedCount(int expectedCount, EventStoreTimeIntervalEnum currInterval, Map<EventStoreTimeIntervalEnum, Integer> countsMap) {
    countsMap.merge(currInterval, expectedCount, (v1, v2) -> v1 + v2);

    EventStoreTimeIntervalEnum.getNextBiggest(currInterval)
            .ifPresent(nextInterval -> addExpectedCount(expectedCount, nextInterval, countsMap));
}
 

import java.util.Map; //導入方法依賴的package包/類
/**
 * Gets the unique words per text and their frequency.
 *
 * @param inputText text to be filtered on words
 * @return map of the unique words and their respective counts
 */
private Map<String, Integer> getUniqueWords(String inputText) {
    String[] words = inputText.split("[,.:;\\s\\n]");
    Map<String, Integer> uniqueWords = new HashMap<>();
    for (String word : words) {
        uniqueWords.merge(word, 1, (integer, integer2) -> integer + integer2);
    }
    uniqueWords.remove("");
    return uniqueWords;
}
 

import java.util.Map; //導入方法依賴的package包/類
public void updateState4MonitorRemoval(long manifestId, String source) {
    List<Long> ciIds = tsDao.getManifestCiIds(manifestId, 3, 10000, true);
    Map<Long, List<CiOpenEvent>> openEvents = opsEventDao.getCiOpenEvents(ciIds);
    Map<String, Long> countersDeltaMap = new HashMap<String, Long>();
    for (Map.Entry<Long, List<CiOpenEvent>> entry : openEvents.entrySet()) {
        long ciId = entry.getKey();
        List<CiOpenEvent> bomOpenEvents = entry.getValue();
        Map<String, List<CiOpenEvent>> eventGroupMap = bomOpenEvents.stream().collect(
        		Collectors.groupingBy(ciOpenEvent -> ciOpenEvent.getName().startsWith(source + ":") ? "expiredOpenEvents" : "validOpenEvents"));
        List<CiOpenEvent> expiredOpenEvents = eventGroupMap.get("expiredOpenEvents");
        
        if (expiredOpenEvents != null && !expiredOpenEvents.isEmpty()) {
            String oldState = coProcessor.getState(bomOpenEvents);
        	expiredOpenEvents.stream().forEach(ciOpenEvent -> opsEventDao.removeOpenEventForCi(ciId, ciOpenEvent.getName()));
        	List<CiOpenEvent> validOpenEvents = eventGroupMap.get("validOpenEvents");
        	if (validOpenEvents == null) 
        		validOpenEvents = Collections.emptyList();
            String newState = coProcessor.getState(validOpenEvents);
            if (!oldState.equals(newState)) {
            	countersDeltaMap.merge(oldState, -1L, Long::sum);
            	countersDeltaMap.merge(newState, 1L, Long::sum);
            }
        }
    }
    if (logger.isDebugEnabled()) {
    	logger.debug("state counter delta for monitor removal for manifest " + manifestId + "-" + source + " : " + countersDeltaMap);
    }
    if (!openEvents.isEmpty()) {
        coProcessor.resetManifestStateCounters(manifestId, ciIds, countersDeltaMap);
    }
}
 

import java.util.Map; //導入方法依賴的package包/類
@Test(dataProvider = "MergeCases")
private void testMerge(String description, Map<IntegerEnum, String> map, Merging.Value oldValue, Merging.Value newValue, Merging.Merger merger, Merging.Value put, Merging.Value result) {
        // add and check initial conditions.
        switch(oldValue) {
            case ABSENT :
                map.remove(EXTRA_KEY);
                assertFalse(map.containsKey(EXTRA_KEY), "key not absent");
                break;
            case NULL :
                map.put(EXTRA_KEY, null);
                assertTrue(map.containsKey(EXTRA_KEY), "key absent");
                assertNull(map.get(EXTRA_KEY), "wrong value");
                break;
            case OLDVALUE :
                map.put(EXTRA_KEY, VALUES[1]);
                assertTrue(map.containsKey(EXTRA_KEY), "key absent");
                assertSame(map.get(EXTRA_KEY), VALUES[1], "wrong value");
                break;
            default:
                fail("unexpected old value");
        }

        String returned = map.merge(EXTRA_KEY,
            newValue == Merging.Value.NULL ? (String) null : VALUES[2],
            merger
            );

        // check result

        switch(result) {
            case NULL :
                assertNull(returned, "wrong value");
                break;
            case NEWVALUE :
                assertSame(returned, VALUES[2], "wrong value");
                break;
            case RESULT :
                assertSame(returned, VALUES[3], "wrong value");
                break;
            default:
                fail("unexpected new value");
        }

        // check map
        switch(put) {
            case ABSENT :
                assertFalse(map.containsKey(EXTRA_KEY), "key not absent");
                break;
            case NULL :
                assertTrue(map.containsKey(EXTRA_KEY), "key absent");
                assertNull(map.get(EXTRA_KEY), "wrong value");
                break;
            case NEWVALUE :
                assertTrue(map.containsKey(EXTRA_KEY), "key absent");
                assertSame(map.get(EXTRA_KEY), VALUES[2], "wrong value");
                break;
            case RESULT :
                assertTrue(map.containsKey(EXTRA_KEY), "key absent");
                assertSame(map.get(EXTRA_KEY), VALUES[3], "wrong value");
                break;
            default:
                fail("unexpected new value");
        }
}
 

import java.util.Map; //導入方法依賴的package包/類
public void forEach(BiConsumer<String, String> consumer) {
    Map<String, Integer> currentIndex = new HashMap<>(valuesByCapitalizedName.size());
    for (String name : headerNames) {
        String key = name.toUpperCase();
        currentIndex.merge(key, 0, (a, b) -> a + 1);
        String value = valuesByCapitalizedName.get(key).get(currentIndex.get(key));
        consumer.accept(name, value);
    }
}
 

import java.util.Map; //導入方法依賴的package包/類
@Test(dataProvider = "hashMapsWithObjects")
void testMergeNonNull(String desc, Supplier<Map<IntKey, IntKey>> ms, IntKey val) {
    // remove a third of the keys
    // call merge() for all keys[]
    // all keys should be present: removed keys now -> EXTRA, other keys -> k-1
    Map<IntKey, IntKey> map = ms.get();
    IntKey[] keys = map.keySet().stream().sorted().toArray(IntKey[]::new);

    // Map to preceding key
    BiFunction<IntKey, IntKey, IntKey> mappingFunction
            = (k, v) -> keys[k.getValue() - 1];
    removeThirdKeys(map, keys);
    for (int i = 1; i < keys.length; i++) {
        IntKey retVal = map.merge(keys[i], val, mappingFunction);
        if (i % 3 != 2) { // key present, should be mapped to k-1
            assertEquals(retVal, keys[i - 1],
                    String.format("compute: retVal(%s[%d])", desc, i));
            assertEquals(keys[i - 1], map.get(keys[i]),
                    String.format("compute: get(%s[%d])", desc, i));
        } else { // odd: was removed, should be replaced with EXTRA
            assertEquals(retVal, val,
                    String.format("compute: retVal(%s[%d])", desc, i));
            assertEquals(val, map.get(keys[i]),
                    String.format("compute: get(%s[%d])", desc, i));
        }
        assertTrue(map.containsKey(keys[i]),
                String.format("compute: containsKey(%s[%d])", desc, i));
    }

    assertEquals(map.size(), keys.length,
            String.format("map expected size#1 m%d != k%d", map.size(), keys.length));
    assertTrue(map.containsValue(val),
            String.format("compute: containsValue(%s[%s])", desc, val));
    assertFalse(map.containsValue(null),
            String.format("compute: !containsValue(%s,[null])", desc));
}
 

import java.util.Map; //導入方法依賴的package包/類
@Test(dataProvider = "mapsWithObjectsAndStrings")
void testMergeNull(String desc, Supplier<Map<Object, Object>> ms, Object val) {
    // remove a third of the keys
    // call merge() for all keys[]
    // result: removed keys -> EXTRA, other keys absent

    Map<Object, Object> map = ms.get();
    Object[] keys = map.keySet().toArray();
    BiFunction<Object, Object, Object> mappingFunction = (k, v) -> null;
    int expectedSize = 0;
    removeThirdKeys(map, keys);
    for (int i = 0; i < keys.length; i++) {
        Object retVal = map.merge(keys[i], val, mappingFunction);
        if (i % 3 != 2) { // key present, func returned null, should be absent from map
            assertNull(retVal,
                    String.format("compute: retVal(%s[%d])", desc, i));
            assertNull(map.get(keys[i]),
                    String.format("compute: get(%s[%d])", desc, i));
            assertFalse(map.containsKey(keys[i]),
                    String.format("compute: containsKey(%s[%d])", desc, i));
        } else { // odd: was removed, should now be mapped to EXTRA
            assertEquals(retVal, val,
                    String.format("compute: retVal(%s[%d])", desc, i));
            assertEquals(val, map.get(keys[i]),
                    String.format("compute: get(%s[%d])", desc, i));
            assertTrue(map.containsKey(keys[i]),
                    String.format("compute: containsKey(%s[%d])", desc, i));
            expectedSize++;
        }
        assertFalse(map.containsValue(keys[i]),
                String.format("compute: containsValue(%s[%s])", desc, i));
    }
    assertTrue(map.containsValue(val),
            String.format("compute: containsValue(%s[%s])", desc, val));
    assertEquals(map.size(), expectedSize,
            String.format("map expected size#1 m%d != k%d", map.size(), expectedSize));
}
 

import java.util.Map; //導入方法依賴的package包/類
private static List<NlpFocus<DepNode, DepTree>> filterMinCount(int minCount,
                                                               List<NlpFocus<DepNode, DepTree>> data) {
    Map<String, Integer> counts = new HashMap<>();
    for (NlpFocus<DepNode, DepTree> instance : data) {
        String lemma = instance.focus().feature(FeatureType.Predicate);
        counts.merge(lemma, 1, (prev, one) -> prev + one);
    }
    return data.stream()
            .filter(instance -> {
                String predicate = instance.focus().feature(FeatureType.Predicate);
                return counts.get(predicate) >= minCount;
            })
            .collect(Collectors.toList());
}