NamedConnectionPool (xmlBlaster 2.2.0 API)

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xmlBlaster 2.2.0 API

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org.xmlBlaster.protocol.jdbc
Class NamedConnectionPool

java.lang.Object
  org.xmlBlaster.protocol.jdbc.NamedConnectionPool

public class NamedConnectionPool
extends java.lang.Object
extends java.lang.Object

This is a specialized JDBC connection pool for xmlBlaster.

It allows accessing any number of different databases with arbitrary login users.
Every database user is separately pooled for maximum performance.
Every DB request needs to pass the DB-url, login name and password, since the clients are not permanently connected.
Unused connection pools are freed after some time.

The timeout parameters and pool size is adjustable.

The connections are established on demand (lazy allocation). Pre-allocation is currently not implemented. The first SQL request (for example with Oracle) consumes about 1 second to establish the connection, the following requests get this connection from the pool, which is below 1 millisecond. If more than one SQL requests are done simultaneously, the pool increases the number of parallel connections.

Load the drivers before using this pool, e.g.

    java -Djdbc.drivers=foo.bah.Driver:wombat.sql.Driver:bad.taste.ourDriver ...

or in xmlBlaster.properties, e.g.

    JdbcDriver.drivers=oracle.jdbc.driver.OracleDriver,org.gjt.mm.mysql.Driver:postgresql.Driver,de.sag.jdbc.adabasd.ADriver:sun.jdbc.odbc.JdbcOdbcDriver:com.sybase.jdbc2.jdbc.SybDriver

You use reserve() to get a connection and need to call release() after using it, note that the connection parameters are optional:

    String dbStmt = "select * from user_table";
    java.sql.Connection con = namedPool.reserve(dbUrl, dbUser, dbPasswd, 60*60*1000L, 100, 10*60*1000L);
    java.sql.Statement stmt = null;
    java.sql.ResultSet rs = null;
    try {
       stmt = con.createStatement();
       rs = stmt.executeQuery(dbStmt);
    } finally {
       if (rs!=null) rs.close();
       if (stmt!=null) stmt.close();
       if (con!=null) namedPool.release(dbUrl, user, pw, con);
    }

Since:: xmlBlaster 0.78
See Also:: PoolManager, ResourceWrapper

Nested Class Summary
`private class`	`NamedConnectionPool.UnnamedConnectionPool` Inner class, every user of the Named pool has its own connection pool.

Field Summary
`private Global`	`glob`
`private static java.util.logging.Logger`	`log`
`private static java.lang.String`	`ME`
`private java.lang.Object`	`meetingPoint`
`private java.util.Hashtable`	`namedPools`

Constructor Summary
`NamedConnectionPool(Global glob)`

Method Summary
`(package private) void`	`destroy()` Destroy the complete named pool of all users.
`(package private) void`	`destroy(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd)` Destroy the JDBC connection pool from a specific user.
`(package private) void`	`eraseConnection(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd, java.sql.Connection con)` Use this method to destroy the given JDBC connection.
`private java.lang.String`	`getKey(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd)`
`private NamedConnectionPool.UnnamedConnectionPool`	`getPool(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd)`
`static void`	`main(java.lang.String[] args)` For testing only.
`(package private) void`	`release(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd, java.sql.Connection con)` Use this method to release a JDBC connection.
`(package private) java.sql.Connection`	`reserve(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd)` Use this method to get a JDBC connection.
`(package private) java.sql.Connection`	`reserve(java.lang.String dbUrl, java.lang.String dbUser, java.lang.String dbPasswd, long eraseUnusedPoolTimeout, int maxInstances, long idleToErase)` Use this method to get a JDBC connection.
`java.lang.String`	`toXml()` Dump state of this object into a XML ASCII string.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

ME

private static final java.lang.String ME

See Also:: Constant Field Values

glob

private Global glob

log

private static java.util.logging.Logger log

namedPools

private java.util.Hashtable namedPools

meetingPoint

private final java.lang.Object meetingPoint

Constructor Detail