Package com.helger.mail.datahandler

Class DataSourceStreamingDataHandler

java.lang.Object

jakarta.activation.DataHandler

com.helger.mail.datahandler.AbstractStreamingDataHandler

com.helger.mail.datahandler.DataSourceStreamingDataHandler

All Implemented Interfaces:

Closeable, AutoCloseable

public class DataSourceStreamingDataHandler
extends AbstractStreamingDataHandler

An implementation of AbstractStreamingDataHandler using DataSource as the source.

Author:

Philip Helger

Constructor Summary

Constructors

Constructor	Description
DataSourceStreamingDataHandler(jakarta.activation.DataSource aDataSource)

Method Summary

Modifier and Type	Method	Description
void	close()
InputStream	readOnce()	Works like DataHandler.getInputStream() except that this method can be invoked only once. This is used as a signal from the caller that there will be no further DataHandler.getInputStream() invocation nor AbstractStreamingDataHandler.readOnce() invocation on this object (which would result in IOException.) When DataHandler is backed by a streaming BLOB (such as an attachment in a web service read from the network), this allows the callee to avoid unnecessary buffering. Note that it is legal to call DataHandler.getInputStream() multiple times and then call AbstractStreamingDataHandler.readOnce() afterward.

Methods inherited from class com.helger.mail.datahandler.AbstractStreamingDataHandler

getHrefCid, setHrefCid

Methods inherited from class jakarta.activation.DataHandler

getAllCommands, getBean, getCommand, getContent, getContentType, getDataSource, getInputStream, getName, getOutputStream, getPreferredCommands, getTransferData, getTransferDataFlavors, isDataFlavorSupported, setCommandMap, setDataContentHandlerFactory, writeTo

Methods inherited from class java.lang.Object

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

Constructor Detail

DataSourceStreamingDataHandler

public DataSourceStreamingDataHandler(@Nonnull
                                      jakarta.activation.DataSource aDataSource)

Method Detail

readOnce

public InputStream readOnce()
                     throws IOException

Description copied from class: AbstractStreamingDataHandler

Works like DataHandler.getInputStream() except that this method can be invoked only once.
This is used as a signal from the caller that there will be no further DataHandler.getInputStream() invocation nor AbstractStreamingDataHandler.readOnce() invocation on this object (which would result in IOException.)
When DataHandler is backed by a streaming BLOB (such as an attachment in a web service read from the network), this allows the callee to avoid unnecessary buffering.
Note that it is legal to call DataHandler.getInputStream() multiple times and then call AbstractStreamingDataHandler.readOnce() afterward. Streams created such a way can be read in any order - there's no requirement that streams created earlier must be read first.

Specified by:

readOnce in class AbstractStreamingDataHandler

Returns:

always non-null. Represents the content of this BLOB. The returned stream is generally not buffered, so for better performance read in a big batch or wrap this into BufferedInputStream.

Throws:

IOException - if any i/o error

close

public void close()
           throws IOException

Throws:

IOException