org.springframework.messaging.support

Class NativeMessageHeaderAccessor

java.lang.Object

org.springframework.messaging.support.MessageHeaderAccessor

org.springframework.messaging.support.NativeMessageHeaderAccessor

Direct Known Subclasses:

JmsMessageHeaderAccessor, SimpMessageHeaderAccessor

public class NativeMessageHeaderAccessor
extends MessageHeaderAccessor

MessageHeaderAccessor sub-class that supports storage and access of headers from an external source such as a message broker. Headers from the external source are kept separate from other headers, in a sub-map under the key NATIVE_HEADERS. This allows separating processing headers from headers that need to be sent to or received from the external source.

This class is likely to be used through indirectly through a protocol specific sub-class that also provide factory methods to translate message headers to an from an external messaging source.

Since:

4.0

Author:

Rossen Stoyanchev

Field Summary

Fields

Modifier and Type	Field and Description
static String	NATIVE_HEADERS The header name used to store native headers.

Fields inherited from class org.springframework.messaging.support.MessageHeaderAccessor

DEFAULT_CHARSET

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NativeMessageHeaderAccessor() Protected constructor to create a new instance.
protected	NativeMessageHeaderAccessor(Map<String,List<String>> nativeHeaders) Protected constructor to create an instance with the given native headers.
protected	NativeMessageHeaderAccessor(Message<?> message) Protected constructor that copies headers from another message.

Method Summary

Modifier and Type	Method and Description
void	addNativeHeader(String name, String value) Add the specified native header value to existing values.
void	addNativeHeaders(MultiValueMap<String,String> headers) Add the specified native headers to existing values.
boolean	containsNativeHeader(String headerName) Whether the native header map contains the give header name.
void	copyHeaders(Map<String,?> headersToCopy) Copy the name-value pairs from the provided Map.
String	getFirstNativeHeader(String headerName) Return the first value for the specified native header, if present.
static String	getFirstNativeHeader(String headerName, Map<String,Object> headers) Return the first value for the specified native header, or null if none.
List<String>	getNativeHeader(String headerName) Return all values for the specified native header, if present.
protected Map<String,List<String>>	getNativeHeaders() Subclasses can use this method to access the "native" headers sub-map.
List<String>	removeNativeHeader(String headerName) Remove the specified native header value replacing existing values.
void	setHeader(String name, Object value) Set the value for the given header name.
void	setImmutable() By default when MessageHeaderAccessor.getMessageHeaders() is called, "this" MessageHeaderAccessor instance can no longer be used to modify the underlying message headers.
void	setNativeHeader(String name, String value) Set the specified native header value replacing existing values.
Map<String,List<String>>	toNativeHeaderMap() Return a copy of the native headers sub-map, or an empty map.

Methods inherited from class org.springframework.messaging.support.MessageHeaderAccessor

copyHeadersIfAbsent, createAccessor, getAccessor, getAccessor, getAccessor, getContentType, getDetailedLogMessage, getDetailedPayloadLogMessage, getErrorChannel, getHeader, getId, getMessageHeaders, getMutableAccessor, getReplyChannel, getShortLogMessage, getShortPayloadLogMessage, getTimestamp, isModified, isMutable, isReadableContentType, isReadOnly, removeHeader, removeHeaders, setContentType, setErrorChannel, setErrorChannelName, setHeaderIfAbsent, setLeaveMutable, setModified, setReplyChannel, setReplyChannelName, toMap, toMessageHeaders, toString, verifyType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

NATIVE_HEADERS

public static final String NATIVE_HEADERS

The header name used to store native headers.

See Also:

Constant Field Values

Constructor Detail

NativeMessageHeaderAccessor

protected NativeMessageHeaderAccessor()

Protected constructor to create a new instance.

NativeMessageHeaderAccessor

protected NativeMessageHeaderAccessor(@Nullable
                                      Map<String,List<String>> nativeHeaders)

Protected constructor to create an instance with the given native headers.

Parameters:

nativeHeaders - native headers to create the message with (may be null)

NativeMessageHeaderAccessor

protected NativeMessageHeaderAccessor(@Nullable
                                      Message<?> message)

Protected constructor that copies headers from another message.

Method Detail

getNativeHeaders

@Nullable
protected Map<String,List<String>> getNativeHeaders()

Subclasses can use this method to access the "native" headers sub-map.

toNativeHeaderMap

public Map<String,List<String>> toNativeHeaderMap()

Return a copy of the native headers sub-map, or an empty map.

setImmutable

public void setImmutable()

Description copied from class: MessageHeaderAccessor

By default when MessageHeaderAccessor.getMessageHeaders() is called, "this" MessageHeaderAccessor instance can no longer be used to modify the underlying message headers. However if MessageHeaderAccessor.setLeaveMutable(boolean) is used, this method is necessary to indicate explicitly when the MessageHeaders instance should no longer be modified.

Overrides:

setImmutable in class MessageHeaderAccessor

setHeader

public void setHeader(String name,
                      @Nullable
                      Object value)

Description copied from class: MessageHeaderAccessor

Set the value for the given header name.

If the provided value is null, the header will be removed.

Overrides:

setHeader in class MessageHeaderAccessor

copyHeaders

public void copyHeaders(@Nullable
                        Map<String,?> headersToCopy)

Description copied from class: MessageHeaderAccessor

Copy the name-value pairs from the provided Map.

This operation will overwrite any existing values. Use MessageHeaderAccessor.copyHeadersIfAbsent(Map) to avoid overwriting values.

Overrides:

copyHeaders in class MessageHeaderAccessor

containsNativeHeader

public boolean containsNativeHeader(String headerName)

Whether the native header map contains the give header name.

Parameters:

headerName - the name of the header

getNativeHeader

@Nullable
public List<String> getNativeHeader(String headerName)

Return all values for the specified native header, if present.

Parameters:

headerName - the name of the header

Returns:

the associated values, or null if none

getFirstNativeHeader

@Nullable
public String getFirstNativeHeader(String headerName)

Return the first value for the specified native header, if present.

Parameters:

headerName - the name of the header

Returns:

the associated value, or null if none

setNativeHeader

public void setNativeHeader(String name,
                            @Nullable
                            String value)

Set the specified native header value replacing existing values.

In order for this to work, the accessor must be mutable. See MessageHeaderAccessor for details.

addNativeHeader

public void addNativeHeader(String name,
                            @Nullable
                            String value)

Add the specified native header value to existing values.

In order for this to work, the accessor must be mutable. See MessageHeaderAccessor for details.

Parameters:

name - the name of the header

value - the header value to set

addNativeHeaders

public void addNativeHeaders(@Nullable
                             MultiValueMap<String,String> headers)

Add the specified native headers to existing values.

Parameters:

headers - the headers to set

removeNativeHeader

@Nullable
public List<String> removeNativeHeader(String headerName)

Remove the specified native header value replacing existing values.

In order for this to work, the accessor must be mutable. See MessageHeaderAccessor for details.

Parameters:

headerName - the name of the header

Returns:

the associated values, or null if the header was not present

getFirstNativeHeader

@Nullable
public static String getFirstNativeHeader(String headerName,
                                                    Map<String,Object> headers)

Return the first value for the specified native header, or null if none.

Parameters:

headerName - the name of the header

headers - the headers map to introspect

Returns:

the associated value, or null if none