common.java~6~

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package com.bict;
import java.sql.*;
public class Common {
    /*获取数据库连接*/
    public static Connection getConnection(){
          Connection con=null;
          try{
              Class.forName("org.gjt.mm.mysql.Driver");
              String str="jdbc:mysql://localhost:3306/test";
              con=DriverManager.getConnection(str,"root","");
          }catch(Exception e){
              e.printStackTrace();
          }
          return con;
    }
    /*释放数据库连接*/
    public static void freeConnection (Connection con){
         if(con!=null){
            try {
                con.close();
            } catch(SQLException ex) {
                ex.printStackTrace();
            }
         }
    }
    /*运行非更新型SQL语句*/
    public static ResultSet executeQuery(String sql){
        ResultSet rs=null;
        Connection con=getConnection();
        try {
            Statement st = con.createStatement();
            rs=st.executeQuery(sql);
        } catch(SQLException ex) {
            ex.printStackTrace();
        }finally{
            freeConnection(con);
        }
        return rs;
    }
    /*获取查询结果的记录数*/
    public static int getResultCount(String sql){
         int result=-1;
         ResultSet rs=executeQuery(sql);
        try {
            rs.last();
            result=rs.getRow();
        } catch(SQLException ex) {
            ex.printStackTrace();
        }
         return result;
    }

}