MyBatis官方文档
介绍
- This is a simple, synchronous, thread-safe database connection pool.
源码
成员方法
private static final Log log = LogFactory.getLog(PooledDataSource.class);
private final PoolState state = new PoolState(this);
private final UnpooledDataSource dataSource;
// OPTIONAL CONFIGURATION FIELDS
protected int poolMaximumActiveConnections = 10;
protected int poolMaximumIdleConnections = 5;
protected int poolMaximumCheckoutTime = 20000;
protected int poolTimeToWait = 20000;
protected int poolMaximumLocalBadConnectionTolerance = 3;
protected String poolPingQuery = "NO PING QUERY SET";
protected boolean poolPingEnabled;
protected int poolPingConnectionsNotUsedFor;
private int expectedConnectionTypeCode;
成员方法
/*
* Closes all active and idle connections in the pool
*/
public void forceCloseAll() {
// synchronized 给对象加锁
synchronized (state) {
expectedConnectionTypeCode = assembleConnectionTypeCode(dataSource.getUrl(), dataSource.getUsername(), dataSource.getPassword());
for (int i = state.activeConnections.size(); i > 0; i--) {
try {
PooledConnection conn = state.activeConnections.remove(i - 1);
conn.invalidate();
Connection realConn = conn.getRealConnection();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
for (int i = state.idleConnections.size(); i > 0; i--) {
try {
PooledConnection conn = state.idleConnections.remove(i - 1);
conn.invalidate();
Connection realConn = conn.getRealConnection();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
}
if (log.isDebugEnabled()) {
log.debug("PooledDataSource forcefully closed/removed all connections.");
}
}
protected void pushConnection(PooledConnection conn) throws SQLException {
synchronized (state) {
state.activeConnections.remove(conn);
if (conn.isValid()) {
if (state.idleConnections.size() < poolMaximumIdleConnections && conn.getConnectionTypeCode() == expectedConnectionTypeCode) {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback();
}
PooledConnection newConn = new PooledConnection(conn.getRealConnection(), this);
state.idleConnections.add(newConn);
newConn.setCreatedTimestamp(conn.getCreatedTimestamp());
newConn.setLastUsedTimestamp(conn.getLastUsedTimestamp());
conn.invalidate();
if (log.isDebugEnabled()) {
log.debug("Returned connection " + newConn.getRealHashCode() + " to pool.");
}
state.notifyAll();
} else {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback();
}
conn.getRealConnection().close();
if (log.isDebugEnabled()) {
log.debug("Closed connection " + conn.getRealHashCode() + ".");
}
conn.invalidate();
}
} else {
if (log.isDebugEnabled()) {
log.debug("A bad connection (" + conn.getRealHashCode() + ") attempted to return to the pool, discarding connection.");
}
state.badConnectionCount++;
}
}
}