org.springframework.integration.file

Class FileWritingMessageHandler

java.lang.Object

org.springframework.integration.context.IntegrationObjectSupport

org.springframework.integration.handler.AbstractMessageHandler

org.springframework.integration.handler.AbstractMessageProducingHandler

org.springframework.integration.handler.AbstractReplyProducingMessageHandler

org.springframework.integration.file.FileWritingMessageHandler

All Implemented Interfaces:

org.reactivestreams.Subscriber<org.springframework.messaging.Message<?>>, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanClassLoaderAware, org.springframework.beans.factory.BeanFactoryAware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.InitializingBean, org.springframework.context.ApplicationContextAware, org.springframework.context.Lifecycle, org.springframework.core.Ordered, org.springframework.integration.context.ExpressionCapable, org.springframework.integration.context.Orderable, org.springframework.integration.core.MessageProducer, org.springframework.integration.handler.HeaderPropagationAware, org.springframework.integration.handler.MessageTriggerAction, org.springframework.integration.support.context.NamedComponent, org.springframework.integration.support.management.ConfigurableMetricsAware<org.springframework.integration.support.management.AbstractMessageHandlerMetrics>, org.springframework.integration.support.management.IntegrationManagement, org.springframework.integration.support.management.IntegrationStatsManagement, org.springframework.integration.support.management.MessageHandlerMetrics, org.springframework.integration.support.management.TrackableComponent, org.springframework.messaging.MessageHandler, reactor.core.CoreSubscriber<org.springframework.messaging.Message<?>>

public class FileWritingMessageHandler
extends org.springframework.integration.handler.AbstractReplyProducingMessageHandler
implements org.springframework.context.Lifecycle, org.springframework.integration.handler.MessageTriggerAction

A MessageHandler implementation that writes the Message payload to a file. If the payload is a File object, it will copy the File to the specified destination directory. If the payload is a byte array, a String or an InputStream it will be written directly. Otherwise, the payload type is unsupported, and an Exception will be thrown.

To append a new-line after each write, set the appendNewLine flag to 'true'. It is 'false' by default.

If the 'deleteSourceFiles' flag is set to true, the original Files will be deleted. The default value for that flag is false. See the setDeleteSourceFiles(boolean) method javadoc for more information.

Other transformers may be useful to precede this handler. For example, any Serializable object payload can be converted into a byte array by the PayloadSerializingTransformer. Likewise, any Object can be converted to a String based on its toString() method by the ObjectToStringTransformer.

FileExistsMode.APPEND adds content to an existing file; the file is closed after each write. FileExistsMode.APPEND_NO_FLUSH adds content to an existing file and the file is left open without flushing any data. Data will be flushed based on the flushInterval or when a message is sent to the trigger(Message) method, or a flushIfNeeded method is called.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FileWritingMessageHandler.FlushPredicate When using FileExistsMode.APPEND_NO_FLUSH, an implementation of this interface is called for each file that has pending data to flush and close when flushIfNeeded(FlushPredicate) is invoked.
static interface	FileWritingMessageHandler.MessageFlushPredicate When using FileExistsMode.APPEND_NO_FLUSH an implementation of this interface is called for each file that has pending data to flush when a trigger message is received.

Nested classes/interfaces inherited from class org.springframework.integration.handler.AbstractReplyProducingMessageHandler

org.springframework.integration.handler.AbstractReplyProducingMessageHandler.RequestHandler

Nested classes/interfaces inherited from interface org.springframework.integration.support.management.IntegrationManagement

org.springframework.integration.support.management.IntegrationManagement.ManagementOverrides

Field Summary

Fields inherited from class org.springframework.integration.handler.AbstractMessageProducingHandler

messagingTemplate

Fields inherited from class org.springframework.integration.context.IntegrationObjectSupport

EXPRESSION_PARSER, logger

Fields inherited from interface org.springframework.integration.support.management.IntegrationManagement

METER_PREFIX, RECEIVE_COUNTER_NAME, SEND_TIMER_NAME

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
FileWritingMessageHandler(org.springframework.expression.Expression destinationDirectoryExpression) Constructor which sets the destinationDirectoryExpression.
FileWritingMessageHandler(java.io.File destinationDirectory) Constructor which sets the destinationDirectoryExpression using a LiteralExpression.

Method Summary

Modifier and Type	Method and Description
protected java.io.BufferedOutputStream	createOutputStream(java.io.File fileToWriteTo, boolean append) Create a buffered output stream for the file.
protected java.io.BufferedWriter	createWriter(java.io.File fileToWriteTo, boolean append) Create a buffered writer for the file, for String payloads.
protected void	doInit()
void	flushIfNeeded(FileWritingMessageHandler.FlushPredicate flushPredicate) When using FileExistsMode.APPEND_NO_FLUSH you can invoke this method to selectively flush and close open files.
void	flushIfNeeded(FileWritingMessageHandler.MessageFlushPredicate flushPredicate, org.springframework.messaging.Message<?> filterMessage) When using FileExistsMode.APPEND_NO_FLUSH you can invoke this method to selectively flush and close open files.
protected java.lang.String	getTemporaryFileSuffix()
protected java.lang.Object	handleRequestMessage(org.springframework.messaging.Message<?> requestMessage)
boolean	isRunning()
void	setAppendNewLine(boolean appendNewLine) If 'true' will append a new-line after each write.
void	setAutoCreateDirectory(boolean autoCreateDirectory) Specify whether to create the destination directory automatically if it does not yet exist upon initialization.
void	setBufferSize(int bufferSize) Set the buffer size to use while writing to files; default 8192.
void	setCharset(java.lang.String charset) Set the charset name to use when writing a File from a String-based Message payload.
void	setChmod(int chmod) Set the file permissions after uploading, e.g.
void	setChmodOctal(java.lang.String chmod) String setter for Spring XML convenience.
void	setDeleteSourceFiles(boolean deleteSourceFiles) Specify whether to delete source Files after writing to the destination directory.
void	setExpectReply(boolean expectReply) Specify whether a reply Message is expected.
void	setFileExistsMode(FileExistsMode fileExistsMode) Will set the FileExistsMode that specifies what will happen in case the destination exists.
void	setFileNameGenerator(FileNameGenerator fileNameGenerator) Provide the FileNameGenerator strategy to use when generating the destination file's name.
void	setFlushInterval(long flushInterval) Set the frequency to flush buffers when FileExistsMode.APPEND_NO_FLUSH is being used.
void	setFlushPredicate(FileWritingMessageHandler.MessageFlushPredicate flushPredicate) Set a FileWritingMessageHandler.MessageFlushPredicate to use when flushing files when FileExistsMode.APPEND_NO_FLUSH is being used.
void	setFlushWhenIdle(boolean flushWhenIdle) Determine whether the flushInterval applies only to idle files (default) or whether to flush on that interval after the first write to a previously flushed or new file.
void	setNewFileCallback(java.util.function.BiConsumer<java.io.File,org.springframework.messaging.Message<?>> newFileCallback) Set the callback to use when creating new files.
protected void	setPermissions(java.io.File resultFile) Set permissions on newly written files.
void	setPreserveTimestamp(boolean preserveTimestamp) Set to true to preserve the destination file timestamp.
void	setTemporaryFileSuffix(java.lang.String temporaryFileSuffix) By default, every file that is in the process of being transferred will appear in the file system with an additional suffix, which by default is ".writing".
void	start()
void	stop()
void	trigger(org.springframework.messaging.Message<?> message) When using FileExistsMode.APPEND_NO_FLUSH, you can send a message to this method to flush any file(s) that needs it.

Methods inherited from class org.springframework.integration.handler.AbstractReplyProducingMessageHandler

doInvokeAdvisedRequestHandler, getRequiresReply, handleMessageInternal, hasAdviceChain, onInit, setAdviceChain, setBeanClassLoader, setRequiresReply

Methods inherited from class org.springframework.integration.handler.AbstractMessageProducingHandler

addNotPropagatedHeaders, createOutputMessage, getNotPropagatedHeaders, getOutputChannel, isAsync, produceOutput, resolveErrorChannel, sendErrorMessage, sendOutput, sendOutputs, setAsync, setNotPropagatedHeaders, setOutputChannel, setOutputChannelName, setSendTimeout, shouldCopyRequestHeaders, shouldSplitOutput, updateNotPropagatedHeaders

Methods inherited from class org.springframework.integration.handler.AbstractMessageHandler

configureMetrics, destroy, getActiveCount, getActiveCountLong, getComponentType, getDuration, getErrorCount, getErrorCountLong, getHandleCount, getHandleCountLong, getManagedName, getManagedType, getMaxDuration, getMeanDuration, getMinDuration, getOrder, getOverrides, getStandardDeviationDuration, handleMessage, isCountsEnabled, isLoggingEnabled, isStatsEnabled, onComplete, onError, onNext, onSubscribe, registerMetricsCaptor, reset, setCountsEnabled, setLoggingEnabled, setManagedName, setManagedType, setOrder, setShouldTrack, setStatsEnabled

Methods inherited from class org.springframework.integration.context.IntegrationObjectSupport

afterPropertiesSet, extractTypeIfPossible, generateId, getApplicationContext, getApplicationContextId, getBeanFactory, getBeanName, getChannelResolver, getComponentName, getConversionService, getExpression, getIntegrationProperties, getIntegrationProperty, getMessageBuilderFactory, getTaskScheduler, isInitialized, setApplicationContext, setBeanFactory, setBeanName, setChannelResolver, setComponentName, setConversionService, setMessageBuilderFactory, setPrimaryExpression, setTaskScheduler, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.integration.support.context.NamedComponent

getBeanName, getComponentName

Methods inherited from interface reactor.core.CoreSubscriber

currentContext

Constructor Detail

FileWritingMessageHandler

public FileWritingMessageHandler(java.io.File destinationDirectory)

Constructor which sets the destinationDirectoryExpression using a LiteralExpression.

Parameters:

destinationDirectory - Must not be null

See Also:

FileWritingMessageHandler(Expression)

FileWritingMessageHandler

public FileWritingMessageHandler(org.springframework.expression.Expression destinationDirectoryExpression)

Constructor which sets the destinationDirectoryExpression.

Parameters:

destinationDirectoryExpression - Must not be null

See Also:

FileWritingMessageHandler(File)

Method Detail

setAutoCreateDirectory

public void setAutoCreateDirectory(boolean autoCreateDirectory)

Specify whether to create the destination directory automatically if it does not yet exist upon initialization. By default, this value is true. If set to false and the destination directory does not exist, an Exception will be thrown upon initialization.

Parameters:

autoCreateDirectory - true to create the directory if needed.

setTemporaryFileSuffix

public void setTemporaryFileSuffix(java.lang.String temporaryFileSuffix)

By default, every file that is in the process of being transferred will appear in the file system with an additional suffix, which by default is ".writing". This can be changed by setting this property.

Parameters:

temporaryFileSuffix - The temporary file suffix.

setFileExistsMode

public void setFileExistsMode(FileExistsMode fileExistsMode)

Will set the FileExistsMode that specifies what will happen in case the destination exists. For example FileExistsMode.APPEND instructs this handler to append data to the existing file rather then creating a new file for each Message.

If set to FileExistsMode.APPEND, the adapter will also create a real instance of the LockRegistry to ensure that there is no collisions when multiple threads are writing to the same file.

Otherwise the LockRegistry is set to PassThruLockRegistry which has no effect.

With FileExistsMode.REPLACE_IF_MODIFIED, if the file exists, it is only replaced if its last modified timestamp is different to the source; otherwise, the write is ignored. For File payloads, the actual timestamp of the File is compared; for other payloads, the FileHeaders.SET_MODIFIED is compared to the existing file. If the header is missing, or its value is not a Number, the file is always replaced. This mode will typically only make sense if preserveTimestamp is true.

Parameters:

fileExistsMode - Must not be null

See Also:

setPreserveTimestamp(boolean)

setExpectReply

public void setExpectReply(boolean expectReply)

Specify whether a reply Message is expected. If not, this handler will simply return null for a successful response or throw an Exception for a non-successful response. The default is true.

Parameters:

expectReply - true if a reply is expected.

setAppendNewLine

public void setAppendNewLine(boolean appendNewLine)

If 'true' will append a new-line after each write. It is 'false' by default.

Parameters:

appendNewLine - true if a new-line should be written to the file after payload is written

Since:

4.0.7

getTemporaryFileSuffix

protected java.lang.String getTemporaryFileSuffix()

setFileNameGenerator

public void setFileNameGenerator(FileNameGenerator fileNameGenerator)

Provide the FileNameGenerator strategy to use when generating the destination file's name.

Parameters:

fileNameGenerator - The file name generator.

setDeleteSourceFiles

public void setDeleteSourceFiles(boolean deleteSourceFiles)

Specify whether to delete source Files after writing to the destination directory. The default is false. When set to true, it will only have an effect if the inbound Message has a File payload or a FileHeaders.ORIGINAL_FILE header value containing either a File instance or a String representing the original file path.

Parameters:

deleteSourceFiles - true to delete the source files.

setCharset

public void setCharset(java.lang.String charset)

Set the charset name to use when writing a File from a String-based Message payload.

Parameters:

charset - The charset.

setBufferSize

public void setBufferSize(int bufferSize)

Set the buffer size to use while writing to files; default 8192.

Parameters:

bufferSize - the buffer size.

Since:

4.3

setFlushInterval

public void setFlushInterval(long flushInterval)

Set the frequency to flush buffers when FileExistsMode.APPEND_NO_FLUSH is being used. The interval is approximate; the actual interval will be between flushInterval and flushInterval * 1.33 with an average of flushInterval * 1.167.

Parameters:

flushInterval - the interval.

Since:

4.3

See Also:

setFlushWhenIdle(boolean)

setFlushWhenIdle

public void setFlushWhenIdle(boolean flushWhenIdle)

Determine whether the flushInterval applies only to idle files (default) or whether to flush on that interval after the first write to a previously flushed or new file.

Parameters:

flushWhenIdle - false to flush on the interval after the first write to a closed file.

Since:

4.3.7

See Also:

setFlushInterval(long), setBufferSize(int)

setFlushPredicate

public void setFlushPredicate(FileWritingMessageHandler.MessageFlushPredicate flushPredicate)

Set a FileWritingMessageHandler.MessageFlushPredicate to use when flushing files when FileExistsMode.APPEND_NO_FLUSH is being used. See trigger(Message).

Parameters:

flushPredicate - the predicate.

Since:

4.3

setPreserveTimestamp

public void setPreserveTimestamp(boolean preserveTimestamp)

Set to true to preserve the destination file timestamp. If true and the payload is a File, the payload's lastModified time will be transferred to the destination file. For other payloads, the FileHeaders.SET_MODIFIED header will be used if present and it's a Number.

Parameters:

preserveTimestamp - the preserveTimestamp to set.

Since:

4.3

setChmodOctal

public void setChmodOctal(java.lang.String chmod)

String setter for Spring XML convenience.

Parameters:

chmod - permissions as an octal string e.g "600";

Since:

5.0

See Also:

setChmod(int)

setChmod

public void setChmod(int chmod)

Set the file permissions after uploading, e.g. 0600 for owner read/write. Only applies to file systems that support posix file permissions.

Parameters:

chmod - the permissions.

Throws:

java.lang.IllegalArgumentException - if the value is higher than 0777.

Since:

5.0

setNewFileCallback

public void setNewFileCallback(java.util.function.BiConsumer<java.io.File,org.springframework.messaging.Message<?>> newFileCallback)

Set the callback to use when creating new files. This callback will only be called if fileExistsMode is FileExistsMode.APPEND or FileExistsMode.APPEND_NO_FLUSH and new file has to be created. The callback receives the new result file and the message that triggered the handler.

Parameters:

newFileCallback - a BiConsumer callback to be invoked when new file is created.

Since:

5.1

doInit

protected void doInit()

Overrides:

doInit in class org.springframework.integration.handler.AbstractReplyProducingMessageHandler

start

public void start()

Specified by:

start in interface org.springframework.context.Lifecycle

stop

public void stop()

Specified by:

stop in interface org.springframework.context.Lifecycle

isRunning

public boolean isRunning()

Specified by:

isRunning in interface org.springframework.context.Lifecycle

handleRequestMessage

protected java.lang.Object handleRequestMessage(org.springframework.messaging.Message<?> requestMessage)

Specified by:

handleRequestMessage in class org.springframework.integration.handler.AbstractReplyProducingMessageHandler

setPermissions

protected void setPermissions(java.io.File resultFile)
                       throws java.io.IOException

Set permissions on newly written files.

Parameters:

resultFile - the file.

Throws:

java.io.IOException - any exception.

Since:

5.0

createWriter

protected java.io.BufferedWriter createWriter(java.io.File fileToWriteTo,
                                              boolean append)
                                       throws java.io.FileNotFoundException

Create a buffered writer for the file, for String payloads.

Parameters:

fileToWriteTo - the file.

append - true if we are appending.

Returns:

the writer.

Throws:

java.io.FileNotFoundException - if the file does not exist.

Since:

4.3.8

createOutputStream

protected java.io.BufferedOutputStream createOutputStream(java.io.File fileToWriteTo,
                                                          boolean append)
                                                   throws java.io.FileNotFoundException

Create a buffered output stream for the file.

Parameters:

fileToWriteTo - the file.

append - true if we are appending.

Returns:

the stream.

Throws:

java.io.FileNotFoundException - if not found.

Since:

4.3.8

trigger

public void trigger(org.springframework.messaging.Message<?> message)

When using FileExistsMode.APPEND_NO_FLUSH, you can send a message to this method to flush any file(s) that needs it. By default, the payload must be a regular expression (String or Pattern) that matches the absolutePath of any in-process files. However, if a custom FileWritingMessageHandler.MessageFlushPredicate is provided, the payload can be of any type supported by that implementation.

Specified by:

trigger in interface org.springframework.integration.handler.MessageTriggerAction

Since:

4.3

flushIfNeeded

public void flushIfNeeded(FileWritingMessageHandler.FlushPredicate flushPredicate)

When using FileExistsMode.APPEND_NO_FLUSH you can invoke this method to selectively flush and close open files. For each open file the supplied FileWritingMessageHandler.MessageFlushPredicate.shouldFlush(String, long, long, Message) method is invoked and if true is returned, the file is flushed.

Parameters:

flushPredicate - the FileWritingMessageHandler.FlushPredicate.

Since:

4.3

flushIfNeeded

public void flushIfNeeded(FileWritingMessageHandler.MessageFlushPredicate flushPredicate,
                          org.springframework.messaging.Message<?> filterMessage)

When using FileExistsMode.APPEND_NO_FLUSH you can invoke this method to selectively flush and close open files. For each open file the supplied FileWritingMessageHandler.MessageFlushPredicate.shouldFlush(String, long, long, Message) method is invoked and if true is returned, the file is flushed.

Parameters:

flushPredicate - the FileWritingMessageHandler.MessageFlushPredicate.

filterMessage - an optional message passed into the predicate.

Since:

4.3