gate.persist
Class ConnectionPool
java.lang.Object
gate.persist.ConnectionPool
- public class ConnectionPool
- extends Object
A generic implementation of pool of references to objects of any kind.
It is thread-safe, so, allows multiple users to get and release objects
"simultaneously". In fact, the standard Java synchronization is used.
The base idea is that, a calling routine will try to get
an object from the pool with method Get. On success, it will use the
object and return it in the pool with the method Put.
If there ares no available objects in the pool, Get will return null.
Then the calling routine should create a new object. Further, scenario goes
in the same way - when finished using the object, calling routine shoud Put
it in the pool for future use, instead of leaving it to be garbage-collected.
The pool initially is empty. The only way to increase the number of objects
managed by the pool, is some external process to Put an object, that was
created, instead of previously Get from the pool.
Pool stores only references to currently "free" or available objects. When
some external routine Gets an object from the pool, its reference is not
locked, it is simply removed from the pool.
Constructor Summary |
ConnectionPool(int size,
String url)
Constructs and object pool with specified size. |
Method Summary |
void |
finalize()
|
Connection |
get()
Pulls out an object from the pool. |
boolean |
put(Connection conn)
Puts an object in the pool, those stating that it's "free" or available
for use by another processes and routines. |
connections
private Vector connections
size
private int size
url
private String url
connCount
private int connCount
ConnectionPool
public ConnectionPool(int size,
String url)
- Constructs and object pool with specified size.
- Parameters:
size
- determines the maximum size of the pool. This is the number
free objects that it can manage at the same time
get
public Connection get()
throws SQLException,
ClassNotFoundException
- Pulls out an object from the pool. The reference to the object is removed
from the pool and their is no longer any kind of relation between this
object and the pool. It can be returned back (released) by Put method.
- Returns:
- an object from the pool, if available.
Otherwise, returns null
- Throws:
SQLException
ClassNotFoundException
put
public boolean put(Connection conn)
- Puts an object in the pool, those stating that it's "free" or available
for use by another processes and routines. An object can be put in the pool,
without need to be get from there before.
- Returns:
- true on success
false when the object was not put in the pool,
because the maximal number of references in the pool was riched
finalize
public void finalize()