SQL语句的拼凑

StringBuilder sql = new StringBuilder("SELECT * FROM t_customer WHERE 1=1");
            /*
             * 2. 判断条件，完成向sql中追加where子句
             */
            /*
             * 3. 创建一个ArrayList，用来装载参数值
             */
            List<Object> params = new ArrayList<Object>();
            String cname = criteria.getCname();
            if(cname != null && !cname.trim().isEmpty()) {
                sql.append(" and cname like ?");
                params.add("%" + cname + "%");
            }

            String gender = criteria.getGender();
            if(gender != null && !gender.trim().isEmpty()) {
                sql.append(" and gender=?");
                params.add(gender);
            }

            String cellphone = criteria.getCellphone();
            if(cellphone != null && !cellphone.trim().isEmpty()) {
                sql.append(" and cellphone like ?");
                params.add("%" + cellphone + "%");
            }

            String email = criteria.getEmail();
            if(email != null && !email.trim().isEmpty()) {
                sql.append(" and email like ?");
                params.add("%" + email + "%");
            }