org.springframework.messaging.support

Class MessageBuilder<T>

java.lang.Object

org.springframework.messaging.support.MessageBuilder<T>

Type Parameters:

T - the message payload type

public final class MessageBuilder<T>
extends Object

A builder for creating a GenericMessage (or ErrorMessage if the payload is of type Throwable).

Since:

4.0

Author:

Arjen Poutsma, Mark Fisher, Rossen Stoyanchev

See Also:

GenericMessage, ErrorMessage

Method Summary

Modifier and Type	Method and Description
Message<T>	build()
MessageBuilder<T>	copyHeaders(Map<String,?> headersToCopy) Copy the name-value pairs from the provided Map.
MessageBuilder<T>	copyHeadersIfAbsent(Map<String,?> headersToCopy) Copy the name-value pairs from the provided Map.
static <T> Message<T>	createMessage(T payload, MessageHeaders messageHeaders) A shortcut factory method for creating a message with the given payload and MessageHeaders.
static <T> MessageBuilder<T>	fromMessage(Message<T> message) Create a builder for a new Message instance pre-populated with all of the headers copied from the provided message.
MessageBuilder<T>	removeHeader(String headerName) Remove the value for the given header name.
MessageBuilder<T>	removeHeaders(String... headerPatterns) Removes all headers provided via array of 'headerPatterns'.
MessageBuilder<T>	setErrorChannel(MessageChannel errorChannel)
MessageBuilder<T>	setErrorChannelName(String errorChannelName)
MessageBuilder<T>	setHeader(String headerName, Object headerValue) Set the value for the given header name.
MessageBuilder<T>	setHeaderIfAbsent(String headerName, Object headerValue) Set the value for the given header name only if the header name is not already associated with a value.
MessageBuilder<T>	setHeaders(MessageHeaderAccessor accessor) Set the message headers to use by providing a MessageHeaderAccessor.
MessageBuilder<T>	setReplyChannel(MessageChannel replyChannel)
MessageBuilder<T>	setReplyChannelName(String replyChannelName)
static <T> MessageBuilder<T>	withPayload(T payload) Create a new builder for a message with the given payload.

Methods inherited from class java.lang.Object

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

Method Detail

setHeaders

public MessageBuilder<T> setHeaders(MessageHeaderAccessor accessor)

Set the message headers to use by providing a MessageHeaderAccessor.

Parameters:

accessor - the headers to use

setHeader

public MessageBuilder<T> setHeader(String headerName,
                                   @Nullable
                                   Object headerValue)

Set the value for the given header name. If the provided value is null, the header will be removed.

setHeaderIfAbsent

public MessageBuilder<T> setHeaderIfAbsent(String headerName,
                                           Object headerValue)

Set the value for the given header name only if the header name is not already associated with a value.

removeHeaders

public MessageBuilder<T> removeHeaders(String... headerPatterns)

Removes all headers provided via array of 'headerPatterns'. As the name suggests the array may contain simple matching patterns for header names. Supported pattern styles are: "xxx*", "*xxx", "*xxx*" and "xxx*yyy".

removeHeader

public MessageBuilder<T> removeHeader(String headerName)

Remove the value for the given header name.

copyHeaders

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

Copy the name-value pairs from the provided Map. This operation will overwrite any existing values. Use { copyHeadersIfAbsent(Map) to avoid overwriting values. Note that the 'id' and 'timestamp' header values will never be overwritten.

copyHeadersIfAbsent

public MessageBuilder<T> copyHeadersIfAbsent(@Nullable
                                             Map<String,?> headersToCopy)

Copy the name-value pairs from the provided Map. This operation will not overwrite any existing values.

setReplyChannel

public MessageBuilder<T> setReplyChannel(MessageChannel replyChannel)

setReplyChannelName

public MessageBuilder<T> setReplyChannelName(String replyChannelName)

setErrorChannel

public MessageBuilder<T> setErrorChannel(MessageChannel errorChannel)

setErrorChannelName

public MessageBuilder<T> setErrorChannelName(String errorChannelName)

build

public Message<T> build()

fromMessage

public static <T> MessageBuilder<T> fromMessage(Message<T> message)

Create a builder for a new Message instance pre-populated with all of the headers copied from the provided message. The payload of the provided Message will also be used as the payload for the new message.

If the provided message is an ErrorMessage, the originalMessage it contains, will be passed on to new instance.

Parameters:

message - the Message from which the payload and all headers will be copied

withPayload

public static <T> MessageBuilder<T> withPayload(T payload)

Create a new builder for a message with the given payload.

Parameters:

payload - the payload

createMessage

public static <T> Message<T> createMessage(@Nullable
                                           T payload,
                                           MessageHeaders messageHeaders)

A shortcut factory method for creating a message with the given payload and MessageHeaders.

Note: the given MessageHeaders instance is used directly in the new message, i.e. it is not copied.

Parameters:

payload - the payload to use (never null)

messageHeaders - the headers to use (never null)

Returns:

the created message

Since:

4.1