本文整理了Java中java.util.Map.clear()方法的一些代码示例，展示了Map.clear()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Map.clear()方法的具体详情如下：
包路径：java.util.Map
类名称：Map
方法名：clear

Map.clear介绍

[英]Removes all elements from this Map, leaving it empty.
[中]删除此映射中的所有元素，将其保留为空。

代码示例

代码示例来源：origin: spring-projects/spring-framework

/**
 * Close the bundle View factories on context shutdown.
 */
@Override
public void destroy() throws BeansException {
  for (ConfigurableApplicationContext factory : this.bundleCache.values()) {
    factory.close();
  }
  this.localeCache.clear();
  this.bundleCache.clear();
}

代码示例来源：origin: log4j/log4j

public static void resetLogLevelColorMap() {
 // empty the map
 _logLevelColorMap.clear();
 // repopulate map and reset text color black
 for (int i = 0; i < _allDefaultLevels.length; i++) {
  _logLevelColorMap.put(_allDefaultLevels[i], Color.black);
 }
}

代码示例来源：origin: apache/kafka

private void deepCopy(Map<String, List<TopicPartition>> source, Map<String, List<TopicPartition>> dest) {
  dest.clear();
  for (Entry<String, List<TopicPartition>> entry: source.entrySet())
    dest.put(entry.getKey(), new ArrayList<>(entry.getValue()));
}

代码示例来源：origin: spring-projects/spring-framework

@SuppressWarnings({"unchecked", "rawtypes"})
protected void visitMap(Map<?, ?> mapVal) {
  Map newContent = new LinkedHashMap();
  boolean entriesModified = false;
  for (Map.Entry entry : mapVal.entrySet()) {
    Object key = entry.getKey();
    int keyHash = (key != null ? key.hashCode() : 0);
    Object newKey = resolveValue(key);
    int newKeyHash = (newKey != null ? newKey.hashCode() : 0);
    Object val = entry.getValue();
    Object newVal = resolveValue(val);
    newContent.put(newKey, newVal);
    entriesModified = entriesModified || (newVal != val || newKey != key || newKeyHash != keyHash);
  }
  if (entriesModified) {
    mapVal.clear();
    mapVal.putAll(newContent);
  }
}

代码示例来源：origin: Alluxio/alluxio

/**
  * Resets the mount table state.
  */
 public void reset() {
  MountInfo mountInfo = mMountTable.get(ROOT);
  mMountTable.clear();
  if (mountInfo != null) {
   mMountTable.put(ROOT, mountInfo);
  }
 }
}

代码示例来源：origin: apache/storm

public Map<String, List<FixedTuple>> getAndClearResults() {
  Map<String, List<FixedTuple>> ret = new HashMap<>(emitted_tuples.get(_name));
  emitted_tuples.get(_name).clear();
  return ret;
}

代码示例来源：origin: apache/incubator-dubbo

public static void resetExtensionLoader(Class type) {
  ExtensionLoader loader = EXTENSION_LOADERS.get(type);
  if (loader != null) {
    // Remove all instances associated with this loader as well
    Map<String, Class<?>> classes = loader.getExtensionClasses();
    for (Map.Entry<String, Class<?>> entry : classes.entrySet()) {
      EXTENSION_INSTANCES.remove(entry.getValue());
    }
    classes.clear();
    EXTENSION_LOADERS.remove(type);
  }
}

代码示例来源：origin: google/guava

public void testStandardEntrySet() throws InvocationTargetException {
 @SuppressWarnings("unchecked")
 final Map<String, Boolean> map = mock(Map.class);
 Map<String, Boolean> forward =
   new ForwardingMap<String, Boolean>() {
    @Override
    protected Map<String, Boolean> delegate() {
     return map;
    }
    @Override
    public Set<Entry<String, Boolean>> entrySet() {
     return new StandardEntrySet() {
      @Override
      public Iterator<Entry<String, Boolean>> iterator() {
       return Iterators.emptyIterator();
      }
     };
    }
   };
 callAllPublicMethods(new TypeToken<Set<Entry<String, Boolean>>>() {}, forward.entrySet());
 // These are the methods specified by StandardEntrySet
 verify(map, atLeast(0)).clear();
 verify(map, atLeast(0)).containsKey(anyObject());
 verify(map, atLeast(0)).get(anyObject());
 verify(map, atLeast(0)).isEmpty();
 verify(map, atLeast(0)).remove(anyObject());
 verify(map, atLeast(0)).size();
 verifyNoMoreInteractions(map);
}

代码示例来源：origin: org.slf4j/slf4j-log4j12

@SuppressWarnings({ "rawtypes", "unchecked" })
  public void setContextMap(Map contextMap) {
    Map old = org.apache.log4j.MDC.getContext();
    if (old == null) {
      Iterator entrySetIterator = contextMap.entrySet().iterator();
      while (entrySetIterator.hasNext()) {
        Map.Entry mapEntry = (Map.Entry) entrySetIterator.next();
        org.apache.log4j.MDC.put((String) mapEntry.getKey(), mapEntry.getValue());
      }
    } else {
      old.clear();
      old.putAll(contextMap);
    }
  }
}

代码示例来源：origin: google/guava

public void testStandardValues() throws InvocationTargetException {
 @SuppressWarnings("unchecked")
 final Map<String, Boolean> map = mock(Map.class);
 Map<String, Boolean> forward =
   new ForwardingMap<String, Boolean>() {
    @Override
    protected Map<String, Boolean> delegate() {
     return map;
    }
    @Override
    public Collection<Boolean> values() {
     return new StandardValues();
    }
   };
 callAllPublicMethods(new TypeToken<Collection<Boolean>>() {}, forward.values());
 // These are the methods specified by StandardValues
 verify(map, atLeast(0)).clear();
 verify(map, atLeast(0)).containsValue(anyObject());
 verify(map, atLeast(0)).isEmpty();
 verify(map, atLeast(0)).size();
 verify(map, atLeast(0)).entrySet();
 verifyNoMoreInteractions(map);
}

代码示例来源：origin: google/guava

@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
 this.delegate.replaceAll(function);
 inverse.delegate.clear();
 Entry<K, V> broken = null;
 Iterator<Entry<K, V>> itr = this.delegate.entrySet().iterator();
 while (itr.hasNext()) {
  Entry<K, V> entry = itr.next();
  K k = entry.getKey();
  V v = entry.getValue();
  K conflict = inverse.delegate.putIfAbsent(v, k);
  if (conflict != null) {
   broken = entry;
   // We're definitely going to throw, but we'll try to keep the BiMap in an internally
   // consistent state by removing the bad entry.
   itr.remove();
  }
 }
 if (broken != null) {
  throw new IllegalArgumentException("value already present: " + broken.getValue());
 }
}

代码示例来源：origin: apache/ignite

/**
   * @param cmpId component ID.
   */
  private void reinitNodeSpecData(int cmpId) {
    nodeSpecificData.clear();
    for (Map.Entry<UUID, Map<Integer, Serializable>> e : DiscoveryDataBag.this.nodeSpecificData.entrySet()) {
      if (e.getValue() != null && e.getValue().containsKey(cmpId))
        nodeSpecificData.put(e.getKey(), e.getValue().get(cmpId));
    }
  }
}

代码示例来源：origin: rest-assured/rest-assured

/**
 * Set the default headers to add to all requests made by this builder
 * instance.  These values will replace any previously set default headers.
 *
 * @param headers map of header names & values.
 */
public void setHeaders(Map<?, ?> headers) {
  this.defaultRequestHeaders.clear();
  if (headers == null) return;
  for (Object key : headers.keySet()) {
    Object val = headers.get(key);
    if (val == null) continue;
    this.defaultRequestHeaders.put(key.toString(), val.toString());
  }
}

代码示例来源：origin: spring-projects/spring-framework

/**
 * Configure path prefixes to apply to controller methods.
 * <p>Prefixes are used to enrich the mappings of every {@code @RequestMapping}
 * method whose controller type is matched by a corresponding
 * {@code Predicate} in the map. The prefix for the first matching predicate
 * is used, assuming the input map has predictable order.
 * <p>Consider using {@link org.springframework.web.method.HandlerTypePredicate
 * HandlerTypePredicate} to group controllers.
 * @param prefixes a map with path prefixes as key
 * @since 5.1
 * @see org.springframework.web.method.HandlerTypePredicate
 */
public void setPathPrefixes(Map<String, Predicate<Class<?>>> prefixes) {
  this.pathPrefixes.clear();
  prefixes.entrySet().stream()
      .filter(entry -> StringUtils.hasText(entry.getKey()))
      .forEach(entry -> this.pathPrefixes.put(entry.getKey(), entry.getValue()));
}

代码示例来源：origin: jenkinsci/jenkins

private static ProcessBuilder environment(ProcessBuilder pb, String[] env) {
  if(env!=null) {
    Map<String, String> m = pb.environment();
    m.clear();
    for (String e : env) {
      int idx = e.indexOf('=');
      m.put(e.substring(0,idx),e.substring(idx+1,e.length()));
    }
  }
  return pb;
}

代码示例来源：origin: alibaba/jstorm

public Map<String, List<FixedTuple>> getAndClearResults() {
  Map<String, List<FixedTuple>> ret = new HashMap<String, List<FixedTuple>>(emitted_tuples.get(_name));
  emitted_tuples.get(_name).clear();
  return ret;
}

代码示例来源：origin: apache/incubator-dubbo

public static void resetExtensionLoader(Class type) {
  ExtensionLoader loader = EXTENSION_LOADERS.get(type);
  if (loader != null) {
    // Remove all instances associated with this loader as well
    Map<String, Class<?>> classes = loader.getExtensionClasses();
    for (Map.Entry<String, Class<?>> entry : classes.entrySet()) {
      EXTENSION_INSTANCES.remove(entry.getValue());
    }
    classes.clear();
    EXTENSION_LOADERS.remove(type);
  }
}

代码示例来源：origin: google/guava

@Override
public void clear() {
 // Clear each collection, to make previously returned collections empty.
 for (Collection<V> collection : map.values()) {
  collection.clear();
 }
 map.clear();
 totalSize = 0;
}

代码示例来源：origin: apache/hive

public Map<String, List<ExprNodeDesc>> getResidualPredicates(boolean clear) {
 Map<String, List<ExprNodeDesc>> oldExprs = new HashMap<String, List<ExprNodeDesc>>();
 for (Map.Entry<String, List<ExprNodeDesc>> entry : nonFinalPreds.entrySet()) {
  List<ExprNodeDesc> converted = new ArrayList<ExprNodeDesc>();
  for (ExprNodeDesc newExpr : entry.getValue()) {
   converted.add(newToOldExprMap.get(newExpr));
  }
  oldExprs.put(entry.getKey(), converted);
 }
 if (clear) {
  nonFinalPreds.clear();
 }
 return oldExprs;
}

代码示例来源：origin: stackoverflow.com

public static <K,R,S,T> Map<K, R> zipWith(Function2<R,S,T> fn, 
    Map<K, S> m1, Map<K, T> m2, Map<K, R> results){
  Set<K> keySet = new HashSet<K>();
  keySet.addAll(m1.keySet());
  keySet.addAll(m2.keySet());
  results.clear();
  for (K key : keySet) {
    results.put(key, fn.eval(m1.get(key), m2.get(key)));
  }
  return results;
 }