mq5.0-source.main.mq-ums.src.main.java.com.sun.messaging.ums.service.CachedConnection Maven / Gradle / Ivy
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package com.sun.messaging.ums.service;
import java.util.ArrayList;
import java.util.Properties;
import java.util.concurrent.Semaphore;
import javax.jms.Connection;
import javax.jms.JMSException;
import com.sun.messaging.ums.common.Constants;
import java.util.logging.Logger;
public class CachedConnection {
private Connection conn = null;
private ArrayList clients = new ArrayList();
private Properties props = null;
private static final String MAX_CLIENTS = "100";
private int maxClients = Integer.parseInt(MAX_CLIENTS);
private boolean isClosed = false;
private Semaphore available = null;
private Logger logger = UMSServiceImpl.logger;
private long timestamp = 0;
public CachedConnection(Connection conn, Properties props) {
this.conn = conn;
this.props = props;
init();
}
private void init() {
try {
String tmp = props.getProperty(Constants.MAX_CLIENT_PER_CONNECTION, MAX_CLIENTS);
maxClients = Integer.parseInt(tmp);
} catch (Exception e) {
e.printStackTrace();
}
available = new Semaphore(maxClients, true);
}
public Connection getConnection() {
checkClosed();
return conn;
}
public synchronized void add(Client client) {
checkClosed();
clients.add(client);
}
public synchronized void remove(Client client) {
clients.remove(client);
}
public synchronized int size() {
return clients.size();
}
/**
* Called by CachedConnectionPool.
* @return
*/
protected boolean reachedMaxCapacity() {
return (available.availablePermits() == 0);
}
/**
* Called by CachedConnectionPool.
*/
protected void acquire() {
if (UMSServiceImpl.debug) {
logger.info ("acquiring semaphore permit, available#: " + available.availablePermits());
}
available.acquireUninterruptibly();
this.setTimestamp();
}
/**
* Called by CachedConnectionPool.
*/
protected void release() {
available.release();
this.setTimestamp();
if (UMSServiceImpl.debug) {
logger.info ("released semaphore, available#: " + available.availablePermits());
}
}
protected boolean inUse() {
boolean isInuse = (available.availablePermits() < this.maxClients);
if (UMSServiceImpl.debug) {
logger.info ("is inuse = " + isInuse + ", available permits=" + available.availablePermits() + " , max capacity=" + maxClients);
}
return isInuse;
}
/**
* This should be called from the pool.
*
* @throws JMSException
*/
protected synchronized void close() throws JMSException {
if (this.available.availablePermits() != this.maxClients) {
throw new RuntimeException(
"Attemp to close a connection with Clients associate with it.");
}
this.isClosed = true;
//XXX remove from pool
conn.close();
}
private synchronized void checkClosed() {
if (isClosed) {
throw new UMSServiceException("Cached connection is closed.");
}
}
private synchronized void setTimestamp() {
this.timestamp = System.currentTimeMillis();
}
public synchronized long getTimestamp() {
return this.timestamp;
}
public String toString() {
return "CachedConnection, conn=" + this.conn + ", available permits=" + this.available.availablePermits() + ", max capacity=" + this.maxClients;
}
}