java.lang.Object
- org.springframework.messaging.MessageHeaders

所有已实现的接口:
Serializable, Map<String,Object>
```
public class MessageHeaders
extends Object
implements Map<String,Object>, Serializable
```
The headers for a Message.
IMPORTANT: This class is immutable. Any mutating operation such as put(..), putAll(..) and others will throw UnsupportedOperationException.
Subclasses do have access to the raw headers, however, via getRawHeaders().
One way to create message headers is to use the MessageBuilder:
```
 MessageBuilder.withPayload("foo").setHeader("key1", "value1").setHeader("key2", "value2");
 
```
A second option is to create GenericMessage passing a payload as Object and headers as a java.util.Map:
```
 Map headers = new HashMap();
 headers.put("key1", "value1");
 headers.put("key2", "value2");
 new GenericMessage("foo", headers);
 
```
A third option is to use MessageHeaderAccessor or one of its subclasses to create specific categories of headers.
从以下版本开始:
4.0
作者:
Arjen Poutsma, Mark Fisher, Gary Russell, Juergen Hoeller
另请参阅:
MessageBuilder, MessageHeaderAccessor, 序列化表格

嵌套类概要
- 从接口继承的嵌套类/接口 java.util.Map
  Map.Entry<K extends Object,V extends Object>

字段概要

字段
修饰符和类型	字段	说明
`static String`	`CONTENT_TYPE`	The key for the message content type.
`static String`	`ERROR_CHANNEL`	The key for the message error channel.
`static String`	`ID`	The key for the Message ID.
`static UUID`	`ID_VALUE_NONE`	UUID for none.
`static String`	`REPLY_CHANNEL`	The key for the message reply channel.
`static String`	`TIMESTAMP`	The key for the message timestamp.

构造器概要

构造器
限定符	构造器	说明
	`MessageHeaders(Map<String,Object> headers)`	Construct a `MessageHeaders` with the given headers.
`protected`	`MessageHeaders(Map<String,Object> headers, UUID id, Long timestamp)`	Constructor providing control over the ID and TIMESTAMP header values.

方法概要

所有方法静态方法实例方法具体方法
修饰符和类型	方法	说明
`void`	`clear()`	Since MessageHeaders are immutable, the call to this method will result in `UnsupportedOperationException`.
`boolean`	`containsKey(Object key)`
`boolean`	`containsValue(Object value)`
`Set<Map.Entry<String,Object>>`	`entrySet()`
`boolean`	`equals(Object other)`
`Object`	`get(Object key)`
`<T> T`	`get(Object key, Class<T> type)`
`Object`	`getErrorChannel()`
`UUID`	`getId()`
`protected static IdGenerator`	`getIdGenerator()`
`protected Map<String,Object>`	`getRawHeaders()`
`Object`	`getReplyChannel()`
`Long`	`getTimestamp()`
`int`	`hashCode()`
`boolean`	`isEmpty()`
`Set<String>`	`keySet()`
`Object`	`put(String key, Object value)`	Since MessageHeaders are immutable, the call to this method will result in `UnsupportedOperationException`.
`void`	`putAll(Map<? extends String,? extends Object> map)`	Since MessageHeaders are immutable, the call to this method will result in `UnsupportedOperationException`.
`Object`	`remove(Object key)`	Since MessageHeaders are immutable, the call to this method will result in `UnsupportedOperationException`.
`int`	`size()`
`String`	`toString()`
`Collection<Object>`	`values()`

从类继承的方法 java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

从接口继承的方法 java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- 字段详细资料
  - ID_VALUE_NONE
```
public static final UUID ID_VALUE_NONE
```
    UUID for none.
  - ID
```
public static final String ID
```
    The key for the Message ID. This is an automatically generated UUID and should never be explicitly set in the header map except in the case of Message deserialization where the serialized Message's generated UUID is being restored.
    另请参阅:
    常量字段值
  - TIMESTAMP
```
public static final String TIMESTAMP
```
    The key for the message timestamp.
    另请参阅:
    常量字段值
  - CONTENT_TYPE
```
public static final String CONTENT_TYPE
```
    The key for the message content type.
    另请参阅:
    常量字段值
  - REPLY_CHANNEL
```
public static final String REPLY_CHANNEL
```
    The key for the message reply channel.
    另请参阅:
    常量字段值
  - ERROR_CHANNEL
```
public static final String ERROR_CHANNEL
```
    The key for the message error channel.
    另请参阅:
    常量字段值
- 构造器详细资料
  - MessageHeaders
```
public MessageHeaders(@Nullable
                      Map<String,Object> headers)
```
    Construct a MessageHeaders with the given headers. An ID and TIMESTAMP headers will also be added, overriding any existing values.
    参数:
    headers - a map with headers to add
  - MessageHeaders
```
protected MessageHeaders(@Nullable
                         Map<String,Object> headers,
                         @Nullable
                         UUID id,
                         @Nullable
                         Long timestamp)
```
    Constructor providing control over the ID and TIMESTAMP header values.
    参数:
    headers - a map with headers to add
    id - the ID header value
    timestamp - the TIMESTAMP header value
- 方法详细资料
  - getRawHeaders
```
protected Map<String,Object> getRawHeaders()
```
  - getIdGenerator
```
protected static IdGenerator getIdGenerator()
```
  - getId
```
@Nullable
public UUID getId()
```
  - getTimestamp
```
@Nullable
public Long getTimestamp()
```
  - getReplyChannel
```
@Nullable
public Object getReplyChannel()
```
  - getErrorChannel
```
@Nullable
public Object getErrorChannel()
```
  - get
```
@Nullable
public <T> T get(Object key,
                 Class<T> type)
```
  - containsKey
```
public boolean containsKey(Object key)
```
    指定者:
    containsKey 在接口中 Map<String,Object>
  - containsValue
```
public boolean containsValue(Object value)
```
    指定者:
    containsValue 在接口中 Map<String,Object>
  - entrySet
```
public Set<Map.Entry<String,Object>> entrySet()
```
    指定者:
    entrySet 在接口中 Map<String,Object>
  - get
```
@Nullable
public Object get(Object key)
```
    指定者:
    get 在接口中 Map<String,Object>
  - isEmpty
```
public boolean isEmpty()
```
    指定者:
    isEmpty 在接口中 Map<String,Object>
  - keySet
```
public Set<String> keySet()
```
    指定者:
    keySet 在接口中 Map<String,Object>
  - size
```
public int size()
```
    指定者:
    size 在接口中 Map<String,Object>
  - values
```
public Collection<Object> values()
```
    指定者:
    values 在接口中 Map<String,Object>
  - put
```
public Object put(String key,
                  Object value)
```
    Since MessageHeaders are immutable, the call to this method will result in UnsupportedOperationException.
    指定者:
    put 在接口中 Map<String,Object>
  - putAll
```
public void putAll(Map<? extends String,? extends Object> map)
```
    Since MessageHeaders are immutable, the call to this method will result in UnsupportedOperationException.
    指定者:
    putAll 在接口中 Map<String,Object>
  - remove
```
public Object remove(Object key)
```
    Since MessageHeaders are immutable, the call to this method will result in UnsupportedOperationException.
    指定者:
    remove 在接口中 Map<String,Object>
  - clear
```
public void clear()
```
    Since MessageHeaders are immutable, the call to this method will result in UnsupportedOperationException.
    指定者:
    clear 在接口中 Map<String,Object>
  - equals
```
public boolean equals(@Nullable
                      Object other)
```
    指定者:
    equals 在接口中 Map<String,Object>
    覆盖:
    equals 在类中 Object
  - hashCode
```
public int hashCode()
```
    指定者:
    hashCode 在接口中 Map<String,Object>
    覆盖:
    hashCode 在类中 Object
  - toString
```
public String toString()
```
    覆盖:
    toString 在类中 Object

类 MessageHeaders

嵌套类概要

从接口继承的嵌套类/接口 java.util.Map

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

从接口继承的方法 java.util.Map

字段详细资料

ID_VALUE_NONE

ID

TIMESTAMP

CONTENT_TYPE

REPLY_CHANNEL

ERROR_CHANNEL

构造器详细资料

MessageHeaders

MessageHeaders

方法详细资料

getRawHeaders

getIdGenerator

getId

getTimestamp

getReplyChannel

getErrorChannel

get

containsKey

containsValue

entrySet

get

isEmpty

keySet

size

values

put

putAll

remove

clear

equals

hashCode

toString