JAVA常用连接数据库关闭数据库等类

java 代码

package com.wide.cabaret.utils;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;

public class DataConn extends Utils{
  ArrayList cons=new ArrayList();
  public DataConn(){
    super();
  }
  /**
   * 數據庫連接
   * @return
   * @throws java.lang.Exception
   */
  public Connection getCon() throws Exception{
    Connection con=null;
    if (cons.size()>0){
      con= (Connection)cons.get(0);
      cons.remove(0);
      if (con!=null&&!con.isClosed()){
        return con;
      }
    }
    String DB_DRIVER=new String();
    String DB_URL=new String();
    String DB_UID=new String();
    String DB_PASSWORD=new String();
    DB_DRIVER = "com.mysql.jdbc.Driver";
    DB_URL = "jdbc:mysql://mysqlserver:3306/808room_com";
    DB_URL += "?useUnicode=true&characterEncoding=BIG5";
    DB_UID = "808room_com";
    DB_PASSWORD = "vs2ur93fa";
    /**
    DB_DRIVER = "com.mysql.jdbc.Driver";
    DB_URL = "jdbc:mysql://localhost:3306/tecc";
    DB_URL += "?useUnicode=true&characterEncoding=big5";
    DB_UID = "root";
    DB_PASSWORD = "root";
    **/
    try{
      Class.forName(DB_DRIVER).newInstance();
      con=DriverManager.getConnection(DB_URL,DB_UID,DB_PASSWORD);
      System.out.println("===============>>>>>>>343434==========="+con);
      return con;
    } catch (SQLException se){
      se.printStackTrace();
      throw se;
    } catch (Exception e){
      e.printStackTrace();
      throw new Exception("提示：數據庫連接失敗！");
    }
  }

  /**
   * 釋放數據庫連接
   * @param con Connection
   */
  public void freeCon(Connection con){
    try{
      if (con!=null){
        con.close();
      }
    } catch (Exception e){
      e.printStackTrace();
    }
  }

  /**
   * 釋放數據集對象
   * @param rs ResultSet
   */
  public void freeCon(ResultSet rs){
    try{
      if (rs!=null){
        rs.close();
      }
    } catch (Exception ex){
      ex.printStackTrace();
    }
  }

  /**
   * 釋放數據庫聯機和數據操作對象
   * @param con Connection
   * @param stmt Statement
   */
  public void freeCon(Connection con, Statement stmt){
    try{
      if (con!=null||stmt!=null){
        con.close();
        stmt.close();
      }
    } catch (Exception e){
      e.printStackTrace();
    }
  }

  /**
   * 釋放數據庫連接以及數據庫操作對象和記錄集對象
   * @param con Connection
   * @param stmt Statement
   * @param rs ResultSet
   */
  public void freeCon(Connection con, Statement stmt, ResultSet rs){
    try{
      if (con!=null||stmt!=null||rs!=null){
        con.close();
        stmt.close();
        rs.close();
      }
    } catch (Exception e){
      e.printStackTrace();
    }
  }
}