原生JDBC的使用

public class ConnDB {
    private Connection ct = null;
   //驱动程序名
    String driver = "com.mysql.jdbc.Driver";
    // URL指向要访问的数据库名scutcs
    String url = "jdbc:mysql://127.0.0.1:3306/develop";
    // MySQL配置时的用户名
    String user = "root";
    // Java连接MySQL配置时的密码
    String password = "wzy123";
 
    public static Connection getConn(){
        try{
            Class.forName(driver);
            ct = DriverManager.getConnection(url, user, password);
        }
        catch(Exception e){
            e.printStackTrace();
        }
        return ct;
    }
 
    public int add(String day,String time,
                String volname,String volclass,String voltel,String volemail){
            Connection con = DbConnect.this.getConn();
            int num = -;
 
            try {
                java.sql.Statement statement = con.createStatement();
                 num = statement.executeUpdate( "insert into tb_volinfo(day,time,volname,volclass,voltel,volemail) "
                        + "values('"+day+"','"+time+"','"+volname+"','"+volclass+"','"+voltel+"','"+volemail+"')");
 
                if(statement!=null){
                    statement.close();
                }
                if(con!=null){
                    con.close();//关闭数据库连接
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
 
            return num;
        }
        public boolean SelectVal(String volname,String voltel){
            Connection con1 = DbConnect.this.getConn();
            ResultSet result =null;
 
            try {
                java.sql.Statement statement = con1.createStatement();
                result = statement.executeQuery("select * from tb_volinfo where volname='"+volname+"' and voltel='"+voltel+"';");
                while(result.next()){
                    return true;
                }
                if(statement!=null){
                    statement.close();
                }
                if(con1!=null){
                    con1.close();//关闭数据库连接
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return false;
        }
}