org.qbroker.jms

Class RedisMessenger

java.lang.Object

org.qbroker.jms.RedisMessenger

All Implemented Interfaces:

Connector

public class RedisMessenger
extends java.lang.Object
implements Connector

RedisMessenger connects to a Redis data store specified by URI and initializes the operations of get and put, etc with JMS Messages on various redis operations.

The following methods, get(), put(), sub(), pub(), query() and update() are supported for the Redis operations. The method of get() gets all the items from a Redis list with the given name. The method of put() puts content of a message to a Redis list. The method of sub() subscribes to a Redis channel with the given name and gets the published messages. The method of pub() publishes the content of a message to a Redis channel. The method of query() is extracts the Redis command from the message and executes it to qeury data. The method of update() extracts the Redis command from the message and executes the command to update the Redis dataset.

Author:

yannanlu@yahoo.com

Constructor Summary

Constructors

Constructor and Description
RedisMessenger(java.util.Map props)

Method Summary

Modifier and Type	Method and Description
void	close()
void	get(XQueue xq) It gets items from a Redis List specified by qName and puts them to the XQ.
java.lang.String	getOperation()
java.lang.StringBuffer	getResult(int type, java.util.Collection collection)
java.lang.StringBuffer	getResult(int type, java.util.Map map)
java.lang.StringBuffer	getResult(int type, java.lang.String[] list)
java.lang.String	getURI()
boolean	isConnected()
void	pub(XQueue xq)
void	put(XQueue xq)
void	query(XQueue xq) It listens to an XQueue for incoming JMS messages and extracts the Redis query command from each message.
java.lang.String	reconnect() reconnects and returns null upon sucess or error msg otherwise
void	sub(XQueue xq) It subscribes to a channel specified by qName and puts messages to the XQ.
void	update(XQueue xq) It listens to an XQueue for incoming JMS messages and extracts the Redis update command from each message.

Methods inherited from class java.lang.Object

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

Constructor Detail

RedisMessenger

public RedisMessenger(java.util.Map props)

Method Detail

get

public void get(XQueue xq)
         throws java.io.IOException

It gets items from a Redis List specified by qName and puts them to the XQ.

Throws:

java.io.IOException

sub

public void sub(XQueue xq)
         throws java.io.IOException

It subscribes to a channel specified by qName and puts messages to the XQ.

Throws:

java.io.IOException

put

public void put(XQueue xq)
         throws TimeoutException,
                java.io.IOException

Throws:

TimeoutException

java.io.IOException

pub

public void pub(XQueue xq)
         throws TimeoutException,
                java.io.IOException

Throws:

TimeoutException

java.io.IOException

query

public void query(XQueue xq)
           throws java.io.IOException,
                  TimeoutException

It listens to an XQueue for incoming JMS messages and extracts the Redis query command from each message. It executes the Redis command to query the dataset from the Redis server. Based on the result type, the query result will be formatted into the customized content. The formatted content will be put into the message body before the message is removed from the XQueue. The requester will be able to get the result content out of the message.

Since the query operation relies on the request, this method will intercept the request and processes it. The incoming message is required to be writeable. The method will set a String property of the message specified by the RCField with the return code, indicating the status of the process to fulfill the request. The requester is required to check the value of the property once it gets the message back. If the return code is 0, the query is successful. Otherwise, the message body will not contain the content out of query operation.

If the MaxIdleTime is set to none-zero, it will monitor the idle time and will throw TimeoutException once the idle time exceeds MaxIdleTime. it is up to the caller to handle this exception.

Throws:

java.io.IOException

TimeoutException

update

public void update(XQueue xq)
            throws java.io.IOException,
                   TimeoutException

It listens to an XQueue for incoming JMS messages and extracts the Redis update command from each message. After the compiling and setting data on the command, it executes the Redis command to update the dataset on the Redis server.

If the MaxIdleTime is set to none-zero, it will monitor the idle time and will throw TimeoutException once the idle time exceeds MaxIdleTime. it is up to the caller to handle this exception.

The original message will not be modified. If the XQueue has enabled the EXTERNAL_XA bit, it will also acknowledge the messages also.

Throws:

java.io.IOException

TimeoutException

getResult

public java.lang.StringBuffer getResult(int type,
                                        java.util.Map map)

getResult

public java.lang.StringBuffer getResult(int type,
                                        java.util.Collection collection)

getResult

public java.lang.StringBuffer getResult(int type,
                                        java.lang.String[] list)

reconnect

public java.lang.String reconnect()

reconnects and returns null upon sucess or error msg otherwise

Specified by:

reconnect in interface Connector

close

public void close()

Specified by:

close in interface Connector

getOperation

public java.lang.String getOperation()

getURI

public java.lang.String getURI()

Specified by:

getURI in interface Connector

isConnected

public boolean isConnected()

Specified by:

isConnected in interface Connector