简单在线留言系统JSP+mysql.rar

package myclass; import java.io.*; import java.sql.*; import java.util.*; public class SQL{ private final String DBDriver = "com.mysql.jdbc.Driver"; private final String url="jdbc:mysql://localhost:3306/db?useUnicode=true&characterEncoding=GBK"; //设置数据库 PreparedStatement smt = null; PreparedStatement prepar = null; private String sql; Connection con = null; ResultSet rs= null; public SQL(){} //链接数据库 public Connection ConnDB(){ try{ Class.forName(DBDriver).newInstance(); }catch (Exception e){ System.out.println("加载驱动程序有错误"); } try{ con=DriverManager.getConnection(url,"root",""); } catch(Exception e) { System.out.print("取得连接时有错误"); } return con; } //接收参数并赋值给私有属性 public void setSql(String sqlstring){ this.sql = sqlstring; } //返回私有变量 public String getSql(){ return sql; } //执行无返回结果的SQL语句（查询）并返回结果集 public ResultSet DoSelect(){ try{ prepar = con.prepareStatement(getSql()); rs = prepar.executeQuery(); return rs; }catch(Exception e){ System.out.print(e); return rs; } } //执行有返回结果的SQL语句（添加、删除、修改） public void DoOther(){ try{ prepar = con.prepareStatement(getSql()); prepar.execute(); //con.commit(); }catch(Exception e){ System.out.print(e); } } }