本文整理了Java中java.util.IdentityHashMap.get()方法的一些代码示例，展示了IdentityHashMap.get()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。IdentityHashMap.get()方法的具体详情如下：
包路径：java.util.IdentityHashMap
类名称：IdentityHashMap
方法名：get

IdentityHashMap.get介绍

[英]Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

More formally, if this map contains a mapping from a key k to a value v such that (key == k), then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

A return value of null does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to null. The #containsKey operation may be used to distinguish these two cases.
[中]返回指定键映射到的值，如果此映射不包含该键的映射，则返回null。
更正式地说，如果这个映射包含从键k到值v的映射，使得（键==k），那么这个方法返回v；否则返回null。（最多可以有一个这样的映射。）
返回值null不一定表示映射不包含键的映射；映射也可能显式地将密钥映射为null。#containsKey操作可用于区分这两种情况。

代码示例

代码示例来源：origin: apache/incubator-dubbo

private static JavaBeanDescriptor createDescriptorIfAbsent(Object obj, JavaBeanAccessor accessor, IdentityHashMap<Object, JavaBeanDescriptor> cache) {
  if (cache.containsKey(obj)) {
    return cache.get(obj);
  } else if (obj instanceof JavaBeanDescriptor) {
    return (JavaBeanDescriptor) obj;
  } else {
    JavaBeanDescriptor result = createDescriptorForSerialize(obj.getClass());
    cache.put(obj, result);
    serializeInternal(result, obj, accessor, cache);
    return result;
  }
}

代码示例来源：origin: apache/incubator-dubbo

private static JavaBeanDescriptor createDescriptorIfAbsent(Object obj, JavaBeanAccessor accessor, IdentityHashMap<Object, JavaBeanDescriptor> cache) {
  if (cache.containsKey(obj)) {
    return cache.get(obj);
  } else if (obj instanceof JavaBeanDescriptor) {
    return (JavaBeanDescriptor) obj;
  } else {
    JavaBeanDescriptor result = createDescriptorForSerialize(obj.getClass());
    cache.put(obj, result);
    serializeInternal(result, obj, accessor, cache);
    return result;
  }
}

代码示例来源：origin: apache/incubator-druid

private WritableMemory getMemory(ByteBuffer buffer)
{
 WritableMemory mem = memCache.get(buffer);
 if (mem == null) {
  mem = WritableMemory.wrap(buffer, ByteOrder.LITTLE_ENDIAN);
  memCache.put(buffer, mem);
 }
 return mem;
}

代码示例来源：origin: spotbugs/spotbugs

private void addHandler(InstructionHandle handle, CodeExceptionGen exceptionHandler) {
    List<CodeExceptionGen> handlerList = codeToHandlerMap.get(handle);
    if (handlerList == null) {
      handlerList = new LinkedList<>();
      codeToHandlerMap.put(handle, handlerList);
    }
    handlerList.add(exceptionHandler);
  }
}

代码示例来源：origin: opentripplanner/OpenTripPlanner

public void addIncoming(Vertex tov, Edge e) {
  List<Edge> toIncoming = incoming.get(tov);
  if (toIncoming == null) {
    toIncoming = new ArrayList<Edge>(INITIAL_EDGELIST_CAPACITY);
    incoming.put(tov, toIncoming);
  }
  if (!toIncoming.contains(e))
    toIncoming.add(e);
}

代码示例来源：origin: opentripplanner/OpenTripPlanner

public void addOutgoing(Vertex fromv, Edge e) {
  List<Edge> fromOutgoing = outgoing.get(fromv);
  if (fromOutgoing == null) {
    fromOutgoing = new ArrayList<Edge>(INITIAL_EDGELIST_CAPACITY);
    outgoing.put(fromv, fromOutgoing);
  }
  if (!fromOutgoing.contains(e))
    fromOutgoing.add(e);
}

代码示例来源：origin: apache/incubator-dubbo

/**
 * If the object has already been written, just write its ref.
 *
 * @return true if we're writing a ref.
 */
@Override
public boolean addRef(Object object)
    throws IOException {
  if (_refs == null)
    _refs = new IdentityHashMap();
  Integer ref = (Integer) _refs.get(object);
  if (ref != null) {
    int value = ref.intValue();
    writeRef(value);
    return true;
  } else {
    _refs.put(object, new Integer(_refs.size()));
    return false;
  }
}

代码示例来源：origin: apache/hive

void addUpdateError(WmTezSession wmTezSession, int endpointVersion) {
 currentLock.lock();
 try {
  Integer existing = current.updateErrors.get(wmTezSession);
  // Only store the latest error, if there are multiple.
  if (existing != null && existing >= endpointVersion) return;
  current.updateErrors.put(wmTezSession, endpointVersion);
  notifyWmThreadUnderLock();
 } finally {
  currentLock.unlock();
 }
}

代码示例来源：origin: wildfly/wildfly

private static Throwable injectDestination(Throwable t, URI destination) {
  StackTraceElement[] stackTrace = new StackTraceElement[5];
  System.arraycopy(t.getStackTrace(), 0, stackTrace, 1, 4);
  stackTrace[0] = new StackTraceElement("", "..use of destination...", destination.toString(), -1);
  t.setStackTrace(stackTrace);
  IdentityHashMap<Throwable, Throwable> encountered = new IdentityHashMap<>(3);
  encountered.put(t, t);
  Throwable cause = t.getCause();
  while (cause != null && encountered.get(cause) == null) {
    encountered.put(cause, cause);
    cause.setStackTrace(Arrays.copyOfRange(cause.getStackTrace(), 0, 5));
    cause = cause.getCause();
  }
  return t;
}

代码示例来源：origin: protostuff/protostuff

/**
 * If you are sure that you are only using a single implementation of your interface/abstract class, then it
 * makes sense to map it directly to its impl class to avoid writing the type.
 * <p>
 * Note that the type is always written when your field is {@link java.lang.Object}.
 * <p>
 * Pojo ids start at 1.
 */
@Override
public <T> Registry mapPojo(Class<? super T> baseClass, Class<T> implClass)
{
  if (strategy.pojoMapping.containsKey(baseClass))
    throw new IllegalArgumentException("Duplicate registration for: " + baseClass);
  BaseHS<?> wrapper = strategy.pojoMapping.get(implClass);
  if (wrapper == null)
    throw new IllegalArgumentException("Must register the impl class first. " + implClass);
  strategy.pojoMapping.put(baseClass, wrapper);
  return this;
}

代码示例来源：origin: apache/geode

private int canonalize(Object object) throws IOException {
 Integer id = writtenObjects.get(object);
 if (id != null) {
  return id.intValue();
 }
 String toString = object.toString();
 id = writtenStrings.get(toString);
 if (id != null) {
  return id.intValue();
 }
 id = Integer.valueOf(nextInt++);
 outputStream.write(STRING_RECORD);
 outputStream.writeUTF(toString);
 writtenObjects.put(object, id);
 writtenStrings.put(toString, id);
 return id.intValue();
}

代码示例来源：origin: spotbugs/spotbugs

/**
 * Get the block in the result CFG corresponding to the given subroutine
 * block.
 *
 * @param subBlock
 *            the subroutine block
 * @return the result CFG block
 */
public BasicBlock getBlock(BasicBlock subBlock) {
  BasicBlock resultBlock = blockMap.get(subBlock);
  if (resultBlock == null) {
    resultBlock = result.allocate();
    blockMap.put(subBlock, resultBlock);
    workList.add(subBlock);
  }
  return resultBlock;
}

代码示例来源：origin: immutables/immutables

@Override
 public AdapterDecider apply(ValueAttribute input) {
  AdapterDecider d = cache.get(input);
  if (d == null) {
   d = new AdapterDecider(input, enums());
   cache.put(input, d);
  }
  return d;
 }
};

代码示例来源：origin: MorphiaOrg/morphia

private void readMappedField(final Datastore datastore, final MappedField mf, final Object entity, final EntityCache cache,
               final DBObject dbObject) {
  CustomMapper selectedMapper = mapperCache.get(mf);
  if (selectedMapper == null) {
    selectedMapper = selectMapper(mf);
    mapperCache.put(mf, selectedMapper);
  }
  selectedMapper.fromDBObject(datastore, dbObject, mf, entity, cache, this);
}

代码示例来源：origin: spotbugs/spotbugs

private void addExceptionHandler(CodeExceptionGen exceptionHandler) {
  InstructionHandle handlerPC = exceptionHandler.getHandlerPC();
  CodeExceptionGen existing = startInstructionToHandlerMap.get(handlerPC);
  if (existing != null) {
    exceptionHandler = merge (this.merger, existing, exceptionHandler);
  }
  startInstructionToHandlerMap.put(handlerPC, exceptionHandler);
}

代码示例来源：origin: robovm/robovm

@Callback
private static void copy(ObjCBlock dst, ObjCBlock src) {
  // Called from the Objective-C side every time the block is copied.
  // Increase the ref count of the block object on the Java side to
  // prevent it from being GCed.
  Object blockObj = src.object();
  Wrapper wrapper = src.wrapper();
  IdentityHashMap<Object, AtomicInteger> refCounts = wrapper.refCounts;
  synchronized (refCounts) {
    AtomicInteger count = refCounts.get(blockObj);
    if (count == null) {
      count = new AtomicInteger(0);
      refCounts.put(blockObj, count);
    }
    count.incrementAndGet();
  }
}

代码示例来源：origin: apache/ignite

/**
 * @param expression Expression.
 * @param calcTypes Calculate types for all the expressions.
 * @return Parsed expression.
 */
private GridSqlElement parseExpression(@Nullable Expression expression, boolean calcTypes) {
  if (expression == null)
    return null;
  GridSqlElement res = (GridSqlElement)h2ObjToGridObj.get(expression);
  if (res == null) {
    res = parseExpression0(expression, calcTypes);
    if (calcTypes)
      res.resultType(fromExpression(expression));
    h2ObjToGridObj.put(expression, res);
  }
  return res;
}

代码示例来源：origin: Graylog2/graylog2-server

@Override
public void exitOr(OrExpression expr) {
  final CodeBlock left = codeSnippet.get(expr.left());
  final CodeBlock right = codeSnippet.get(expr.right());
  codeSnippet.put(expr, CodeBlock.of("($L || $L)", blockOrMissing(left, expr.left()), blockOrMissing(right, expr.right())));
}

代码示例来源：origin: Graylog2/graylog2-server

@Override
public void exitBooleanFuncWrapper(BooleanValuedFunctionWrapper expr) {
  final CodeBlock embeddedExpr = codeSnippet.get(expr.expression());
  // simply forward the other expression's code
  codeSnippet.put(expr, CodeBlock.of("$L", blockOrMissing(embeddedExpr, expr.expression())));
}

代码示例来源：origin: Graylog2/graylog2-server

@Override
public void exitAnd(AndExpression expr) {
  final CodeBlock left = codeSnippet.get(expr.left());
  final CodeBlock right = codeSnippet.get(expr.right());
  codeSnippet.put(expr, CodeBlock.of("($L && $L)", blockOrMissing(left, expr.left()), blockOrMissing(right, expr.right())));
}