connectionpool.java

用JAVA开发的数据库底层核心

package emptyprj.jdbc.util;

import java.sql.SQLException;
import java.sql.Connection;
import javax.sql.DataSource;

public class ConnectionPool {

  private DataSource ds;

  private static ConnectionPool mySelf;

  private ConnectionPool(DataSource ds) {
    this.ds = ds;
  }

  public static void init(DataSource ds) {
    mySelf = new ConnectionPool(ds);
  }

  public static ConnectionPool getInstance() {

    if (mySelf == null) {
      throw new IllegalStateException("Pool not initialized.");
    }
    return mySelf;

  }

  public Connection getConnection() throws SQLException {
    return ds.getConnection();
  }

}