Need Code to create Connection Pool in java

Question

Need code to create the connection pool in java? How does we make sure that connection pool doesn\'t return the same object which is already in use? How happens if client cl

Answer 1

I have one solution for the same to create a connection pool utility which can help you create a pool of default size 10.

@Component public class ConnectionPool { private static final Logger logger = LoggerFactory.getLogger(ConnectionPool.class); private static final int MAX_POOL_SIZE_LIMIT = 10; private BlockingQueue activeConnectinoQueue = new LinkedBlockingQueue<>(); private BlockingQueue usedConnectinoList = new LinkedBlockingQueue<>(); private int initialPoolSize = 5;

@Autowired
@Qualifier("dataSource")
private DataSource dataSource;

public void initConnectionPool() {
    logger.info("ConnectionPool initialization started.");
    if(activeConnectinoQueue.isEmpty() && usedConnectinoList.isEmpty()) {
        for (int i=0; i MAX_POOL_SIZE_LIMIT)) {
        this.initialPoolSize = initialPoolSize;
    }
}

public int getInitialPoolSize() {
    return initialPoolSize;
}

public int getConnectionPoolSize() {
    return activeConnectinoQueue.size() + usedConnectinoList.size();
}

public void setDataSource(AbstractDataSource dataSource) {
    this.dataSource = dataSource;
}

public void closeConnectionPool() {

    logger.info("Closing connectionPool started.");
    close(usedConnectinoList);
    close(activeConnectinoQueue);
    logger.info("ConnectionPool Closed.");
}

private void close(BlockingQueue connectinosQueue) {
    for (int i=0; i

}

now To make it safe we need to attach a factory object..

public enum ConnectionFactory {
CONNECTION;

private ConnectionPool connectionPool;
public void setConnectionPool(ConnectionPool connectionPool) {
    this.connectionPool = connectionPool;
}

public Connection getConnection() {
    return connectionPool.getConnection();
}

public void closeConnection() {
    connectionPool.closeConnectionPool();
}

public void releaseConnection(Connection connection) {
    connectionPool.releaseConnection(connection);
}

public int getConnectionPoolSize() {
    return connectionPool.getConnectionPoolSize();
}

@Component
public static class ConnectionBuilder {
    @Autowired
    private ConnectionPool connectionPool;

    public void setConnectionPool(ConnectionPool connectionPool) {
        this.connectionPool = connectionPool;
    }
    @PostConstruct
    public void postConstruct() {
        for (ConnectionFactory cfactory : EnumSet.allOf(ConnectionFactory.class)) {
            cfactory.setConnectionPool(connectionPool);
        }
    }
}

}