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java.lang.Object | +--IncrementEJBUpes
MQSeries Workflow EJB invocation sample
This sample shows you how to invoke an EJB using an UPES via JMS
This way to invoke EJBs supports transactions, but does not allow you to retrieve the Workflow containers metamodel
This class implements the ContentHandler interface of SAX, which allows it to parse XML files. This implies a lot of unused dummy methods.
This is not a sample on how to parse XML, it only picks out the interesting elements from the incoming XML message and ignores the rest. For a more sophisticated sample on XML parsing in a UPES, please view the "Distributed process sample using XML" available on the MQSeries Workflow product CD. It will be installed in <MQWF_ROOT>\SMP\DPXML. Check there readme.html for details.
Inner Class Summary | |
private class |
IncrementEJBUpes.Data
Subclass to hold the parsed data |
Field Summary | |
private java.lang.StringBuffer |
currentElement
Remembers the content of the currently parsed XML element |
private IncrementEJBUpes.Data |
data
Object to hold the parsed data |
private static java.lang.String |
eol
OS specific end of line |
private com.transarc.jmon.examples.Inc.IncHome |
incrementHome
EJB home |
private java.lang.String |
latestTag
Remembers the latest parsed XML tag |
private org.xml.sax.Locator |
locator
Position indicator for XML parsing |
private javax.jms.QueueConnection |
qConn
JMS queue connection |
private javax.jms.QueueReceiver |
qReader
JMS queue receiver |
private javax.jms.QueueSession |
qSess
JMS queue session |
private javax.jms.QueueSender |
qWriter
JMS queue sender |
private org.xml.sax.XMLReader |
saxParser
XML parser |
private long |
startMillis
For performance measuring |
private long |
stopMillis
For performance measuring |
Constructor Summary | |
IncrementEJBUpes()
Constructor Reads the properties from file, gets the initial JNDI context, initializes the JMS interface, sets up the SAX parser and gets the EJB home |
Method Summary | |
void |
characters(char[] ch,
int start,
int length)
Receive notification of character data. |
void |
endDocument()
Receive notification of the end of a document. |
void |
endElement(java.lang.String namespaceURI,
java.lang.String localName,
java.lang.String name)
Receive notification of the end of an element. |
void |
endPrefixMapping(java.lang.String prefix)
End the scope of a prefix-URI mapping. |
private int |
executeCommand()
Dispatcher method that actually invokes the EJB methods |
void |
ignorableWhitespace(char[] ch,
int start,
int length)
Receive notification of ignorable whitespace in element content. |
static void |
main(java.lang.String[] args)
Main method, no parameter evaluation |
void |
processingInstruction(java.lang.String target,
java.lang.String data)
Receive notification of a processing instruction. |
private void |
run()
Listener method of the UPES Listens in a loop on the queue until a message is received. |
void |
setDocumentLocator(org.xml.sax.Locator loc)
Receive an object for locating the origin of SAX document events. |
void |
shutdown()
Shutdown method for the UPES. |
void |
skippedEntity(java.lang.String name)
Receive notification of a skipped entity. |
void |
startDocument()
Receive notification of the beginning of a document. |
void |
startElement(java.lang.String namespaceURI,
java.lang.String localName,
java.lang.String name,
org.xml.sax.Attributes attrs)
Receive notification of the beginning of an element. |
void |
startPrefixMapping(java.lang.String prefix,
java.lang.String uri)
Begin the scope of a prefix-URI Namespace mapping. |
void |
writeResponse(javax.jms.Message msg)
Formats the XML response message, sets some message properties and sends the message back to the queue specified in the input paramaters properties. |
Methods inherited from class java.lang.Object |
|
Field Detail |
private IncrementEJBUpes.Data data
private org.xml.sax.XMLReader saxParser
private java.lang.String latestTag
private java.lang.StringBuffer currentElement
private org.xml.sax.Locator locator
private javax.jms.QueueConnection qConn
private javax.jms.QueueSession qSess
private javax.jms.QueueReceiver qReader
private javax.jms.QueueSender qWriter
private static final java.lang.String eol
private long startMillis
private long stopMillis
private com.transarc.jmon.examples.Inc.IncHome incrementHome
Constructor Detail |
public IncrementEJBUpes()
Method Detail |
public void characters(char[] ch, int start, int length) throws org.xml.sax.SAXException
This method is part of the SAX API.
The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity so that the Locator provides useful information.
The application must not attempt to read from the array outside of the specified range.
Note that some parsers will report whitespace in element
content using the ignorableWhitespace
method rather than this one (validating parsers must
do so).
ch
- The characters from the XML document.start
- The start position in the array.length
- The number of characters to read from the array.ignorableWhitespace(char[], int, int)
,
Locator
public void endDocument() throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
The SAX parser will invoke this method only once, and it will be the last method invoked during the parse. The parser shall not invoke this method until it has either abandoned parsing (because of an unrecoverable error) or reached the end of input.
startDocument()
public void endElement(java.lang.String namespaceURI, java.lang.String localName, java.lang.String name) throws org.xml.sax.SAXException
This method is part of the SAX API.
The SAX parser will invoke this method at the end of every
element in the XML document; there will be a corresponding
startElement
event for every endElement
event (even when the element is empty).
For information on the names, see startElement.
uri
- The Namespace URI, or the empty string if the
element has no Namespace URI or if Namespace
processing is not being performed.localName
- The local name (without prefix), or the
empty string if Namespace processing is not being
performed.qName
- The qualified XML 1.0 name (with prefix), or the
empty string if qualified names are not available.public void endPrefixMapping(java.lang.String prefix) throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
See startPrefixMapping
for
details. This event will always occur after the corresponding
endElement
event, but the order of
endPrefixMapping
events is not otherwise
guaranteed.
prefix
- The prefix that was being mapping.startPrefixMapping(java.lang.String, java.lang.String)
,
endElement(java.lang.String, java.lang.String, java.lang.String)
private int executeCommand() throws java.lang.Exception
public void ignorableWhitespace(char[] ch, int start, int length)
This method is part of the SAX API and is here just a dummy implementation.
Validating Parsers must use this method to report each chunk of whitespace in element content (see the W3C XML 1.0 recommendation, section 2.10): non-validating parsers may also use this method if they are capable of parsing and using content models.
SAX parsers may return all contiguous whitespace in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.
The application must not attempt to read from the array outside of the specified range.
ch
- The characters from the XML document.start
- The start position in the array.length
- The number of characters to read from the array.characters(char[], int, int)
public static void main(java.lang.String[] args)
public void processingInstruction(java.lang.String target, java.lang.String data) throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
The Parser will invoke this method once for each processing instruction found: note that processing instructions may occur before or after the main document element.
A SAX parser must never report an XML declaration (XML 1.0, section 2.8) or a text declaration (XML 1.0, section 4.3.1) using this method.
target
- The processing instruction target.data
- The processing instruction data, or null if
none was supplied. The data does not include any
whitespace separating it from the target.private void run()
Listener method of the UPES
Listens in a loop on the queue until a message is received.
Then the message is parsed and evaluated. If a shutdown command is received, the loop is left after an empty response is sent back.
The other commands are processed and the result is sent back.
public void setDocumentLocator(org.xml.sax.Locator loc)
This method is part of the SAX API.
SAX parsers are strongly encouraged (though not absolutely required) to supply a locator: if it does so, it must supply the locator to the application by invoking this method before invoking any of the other methods in the ContentHandler interface.
The locator allows the application to determine the end position of any document-related event, even if the parser is not reporting an error. Typically, the application will use this information for reporting its own errors (such as character content that does not match an application's business rules). The information returned by the locator is probably not sufficient for use with a search engine.
Note that the locator will return correct information only during the invocation of the events in this interface. The application should not attempt to use it at any other time.
locator
- An object that can return the location of
any SAX document event.Locator
public void shutdown()
Shutdown method for the UPES.
Terminates queue listening and cleans up the JMS resources.
public void skippedEntity(java.lang.String name) throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
The Parser will invoke this method once for each entity
skipped. Non-validating processors may skip entities if they
have not seen the declarations (because, for example, the
entity was declared in an external DTD subset). All processors
may skip external entities, depending on the values of the
http://xml.org/sax/features/external-general-entities
and the
http://xml.org/sax/features/external-parameter-entities
properties.
name
- The name of the skipped entity. If it is a
parameter entity, the name will begin with '%', and if
it is the external DTD subset, it will be the string
"[dtd]".public void startDocument() throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
The SAX parser will invoke this method only once, before any
other methods in this interface or in org.xml.sax.DTDHandler
DTDHandler (except for setDocumentLocator
).
endDocument()
public void startElement(java.lang.String namespaceURI, java.lang.String localName, java.lang.String name, org.xml.sax.Attributes attrs) throws org.xml.sax.SAXException
This method is part of the SAX API.
The Parser will invoke this method at the beginning of every
element in the XML document; there will be a corresponding
endElement
event for every startElement event
(even when the element is empty). All of the element's content will be
reported, in order, before the corresponding endElement
event.
This event allows up to three name components for each element:
Any or all of these may be provided, depending on the values of the http://xml.org/sax/features/namespaces and the http://xml.org/sax/features/namespace-prefixes properties:
Note that the attribute list provided will contain only
attributes with explicit values (specified or defaulted):
#IMPLIED attributes will be omitted. The attribute list
will contain attributes used for Namespace declarations
(xmlns* attributes) only if the
http://xml.org/sax/features/namespace-prefixes
property is true (it is false by default, and support for a
true value is optional).
uri
- The Namespace URI, or the empty string if the
element has no Namespace URI or if Namespace
processing is not being performed.localName
- The local name (without prefix), or the
empty string if Namespace processing is not being
performed.qName
- The qualified name (with prefix), or the
empty string if qualified names are not available.atts
- The attributes attached to the element. If
there are no attributes, it shall be an empty
Attributes object.endElement(java.lang.String, java.lang.String, java.lang.String)
,
Attributes
public void startPrefixMapping(java.lang.String prefix, java.lang.String uri) throws org.xml.sax.SAXException
This method is part of the SAX API and is here just a dummy implementation.
The information from this event is not necessary for
normal Namespace processing: the SAX XML reader will
automatically replace prefixes for element and attribute
names when the http://xml.org/sax/features/namespaces
feature is true (the default).
There are cases, however, when applications need to use prefixes in character data or in attribute values, where they cannot safely be expanded automatically; the start/endPrefixMapping event supplies the information to the application to expand prefixes in those contexts itself, if necessary.
Note that start/endPrefixMapping events are not
guaranteed to be properly nested relative to each-other:
all startPrefixMapping events will occur before the
corresponding startElement
event,
and all endPrefixMapping
events will occur after the corresponding endElement
event, but their order is not otherwise
guaranteed.
There should never be start/endPrefixMapping events for the "xml" prefix, since it is predeclared and immutable.
prefix
- The Namespace prefix being declared.uri
- The Namespace URI the prefix is mapped to.endPrefixMapping(java.lang.String)
,
startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
public void writeResponse(javax.jms.Message msg)
msg
- The XML message object to which the response corresponds.
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