Java 连接池的工作原理

[java]代码库

String connUrl = "jdbc:mysql://your.database.domain/yourDBname"; 
Class.forName("com.mysql.jdbc.Driver"); 
Connection con = DriverManager.getConnection (connUrl); //源代码片段来自云代码http://yuncode.net
			


  String connUrl = "jdbc:mysql://your.database.domain/yourDBname"; 
  String driver = "com.mysql.jdbc.Driver"; 
  private Map<java.sql.Connection, String> connectionPool = null; 
  private void initPool() { 
    try { 
      connectionPool = new HashMap<java.sql.Connection, String>(); 
      Class.forName(driver); 
      java.sql.Connection con = DriverManager.getConnection(dbUrl); 
      for (int poolInd = poolSize; poolInd < 0; poolInd++) { 
        connectionPool.put(con, "AVAILABLE"); 
      } 
  } 
... //源代码片段来自云代码http://yuncode.net
			


...
  public java.sql.Connection getConnection() throws ClassNotFoundException, SQLException
  { 
      boolean isConnectionAvailable = true; 
      for (Entry<java.sql.Connection, String> entry : connectionPool.entrySet()) { 
          synchronized (entry) { 
              if (entry.getValue()=="AVAILABLE") { 
                  entry.setValue("NOTAVAILABLE"); 
                  return (java.sql.Connection) entry.getKey(); 
              } 
              isConnectionAvailable = false; 
          } 
      } 
      if (!isConnectionAvailable) { 
          Class.forName(driver); 
          java.sql.Connection con = DriverManager.getConnection(connUrl); 
          connectionPool.put(con, "NOTAVAILABLE"); 
          return con; 
      } 
      return null; 
  } 
  ... //源代码片段来自云代码http://yuncode.net
			


... 
public void closeConnection(java.sql.Connection connection) throws ClassNotFoundException, SQLException { 
    for (Entry<java.sql.Connection, String> entry : connectionPool.entrySet()) { 
        synchronized (entry) { 
            if (entry.getKey().equals(connection)) { 
                //Getting Back the conncetion to Pool 
                entry.setValue("AVAILABLE"); 
            } 
        } 
    } 
} 
... //源代码片段来自云代码http://yuncode.net