/** Returns an unused existing or new connection. 2단계: 커넥션 객체를 얻어옵니다. */
public synchronized Connection getConnection() throws Exception {
if (!initialized) {
Class<?> c = Class.forName(_driver);
DriverManager.registerDriver((Driver) c.newInstance());
initialized = true;
}
Connection c = null;
ConnectionObject co = null;
boolean badConnection = false;
for (int i = 0; i < connections.size(); i++) {
co = (ConnectionObject) connections.elementAt(i);
// If connection is not in use, test to ensure it's still valid!
if (!co.inUse) {
try {
badConnection = co.connection.isClosed();
if (!badConnection) badConnection = (co.connection.getWarnings() != null);
} catch (Exception e) {
badConnection = true;
e.printStackTrace();
}
// Connection is bad, remove from pool
if (badConnection) {
connections.removeElementAt(i);
trace("ConnectionPoolManager: Remove disconnected DB connection #" + i);
continue;
}
c = co.connection;
co.inUse = true;
trace("ConnectionPoolManager: Using existing DB connection #" + (i + 1));
break;
}
}
if (c == null) {
c = createConnection();
co = new ConnectionObject(c, true);
connections.addElement(co);
trace("ConnectionPoolManager: Creating new DB connection #" + connections.size());
}
return c;
}
/**
* Marks a flag in the ConnectionObject to indicate this connection is no longer in use 3단계 : 유형에
* 맞게 자원을 반납합니다.
*/
public synchronized void freeConnection(Connection c) {
if (c == null) return;
ConnectionObject co = null;
for (int i = 0; i < connections.size(); i++) {
co = (ConnectionObject) connections.elementAt(i);
if (c == co.connection) {
co.inUse = false;
break;
}
}
for (int i = 0; i < connections.size(); i++) {
co = (ConnectionObject) connections.elementAt(i);
if ((i + 1) > _openConnections && !co.inUse) removeConnection(co.connection);
}
}