Package edu.ucsb.nceas.metacat.database

Class DBConnectionPool

java.lang.Object
edu.ucsb.nceas.metacat.database.DBConnectionPool
All Implemented Interfaces:
Runnable
public class DBConnectionPool extends Object implements Runnable
A class represent a DBConnection pool. Another user can use the object to initial a connection pool, get db connection or return it. This a singleton class, this means only one instance of this class could be in the program at one time.

  • Method Summary

    Modifier and Type
    Method
    Description
    static DBConnection
    getDBConnection(String methodName)
    Method to get a DBConnection in connection pool 1) try to get a DBConnection from DBConnection pool 2) if 1) failed, then check the size of pool.
    static DBConnectionPool
    getInstance()
    Returns the single instance, creating one if it's the first time this method is called.
    int
    getSizeOfDBConnectionPool()
    Method to get the size of DBConnectionPool
    static void
    release()
    Method to shut down all connections
    static void
    returnDBConnection(DBConnection conn, int serialNumber)
    Method to return a connection to DBConnection pool.
    void
    run()
    periodically to recycle the connection
    static boolean
    shrinkConnectionPoolSize()
    Method to decrease dbconnection pool size when all dbconnections are idle If all connections are free and connection pool size greater than initial value, shrink connection pool size to initial value
    static void
    shrinkDBConnectionPoolSize()
    Method to decrease dbconnection pool size when all dbconnections are idle If all connections are free and connection pool size greater than initial value, shrink connection pool size to intital value

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • getInstance

      public static DBConnectionPool getInstance() throws SQLException
      Returns the single instance, creating one if it's the first time this method is called.
      Throws:
      SQLException

    • getSizeOfDBConnectionPool

      public int getSizeOfDBConnectionPool()
      Method to get the size of DBConnectionPool

    • getDBConnection

      public static DBConnection getDBConnection(String methodName) throws SQLException
      Method to get a DBConnection in connection pool 1) try to get a DBConnection from DBConnection pool 2) if 1) failed, then check the size of pool. If the size reach the maximum number of connection, throw a exception: couldn't get one 3) If the size is less than the maximum number of connectio, create some new connections and recursive get one
      Parameters:
      methodName - , the name of method which will check connection out
      Throws:
      SQLException

    • returnDBConnection

      public static void returnDBConnection(DBConnection conn, int serialNumber)
      Method to return a connection to DBConnection pool.
      Parameters:
      conn - , the Connection object need to check in

    • release

      public static void release()
      Method to shut down all connections

    • run

      public void run()
      periodically to recycle the connection
      Specified by:
      run in interface Runnable

    • shrinkConnectionPoolSize

      public static boolean shrinkConnectionPoolSize()
      Method to decrease dbconnection pool size when all dbconnections are idle If all connections are free and connection pool size greater than initial value, shrink connection pool size to initial value

    • shrinkDBConnectionPoolSize

      public static void shrinkDBConnectionPoolSize()
      Method to decrease dbconnection pool size when all dbconnections are idle If all connections are free and connection pool size greater than initial value, shrink connection pool size to intital value