DBUtil之查询数据

/** * 根据条件查询单个数据 * @param con * @param sql * @param cls * @param param * @return * @throws Exception */ public static<T> T selectOne(Connection con,String sql,Class<T> cls,Object...param) throws Exception{ ps = con.prepareStatement(sql); for(int i=0;i<param.length;i++){ ps.setObject(i+1, param[i]); } rs = ps.executeQuery(); T t = null; if (rs.next()) { t = cls.newInstance(); Field[] fields = cls.getDeclaredFields(); for (Field field : fields) { Column column = field.getAnnotation(Column.class); if(column!= null){ Object oValue = rs.getObject(column.values()); if(oValue!= null){ String fieldName = field.getName(); Method m = cls.getDeclaredMethod("set"+fieldName.substring(0,1).toUpperCase() +fieldName.substring(1),oValue.getClass()); m.invoke(t, oValue); } } } } return t; } /** * 根据条件查询一组数据 * @param con * @param sql * @param cls * @param param * @return * @throws Exception */ public static<T> List<T> selectList(Connection con,String sql,Class<T> cls,Object...param) throws Exception{ List<T> tList = new ArrayList<T>(); ps = con.prepareStatement(sql); for(int i=0;i<param.length;i++){ ps.setObject(i+1, param[i]); } rs = ps.executeQuery(); while(rs.next()){ T t = cls.newInstance(); Field[] fields = cls.getDeclaredFields(); for (Field field : fields) { Column column = field.getAnnotation(Column.class); if(column!= null){ Object oValue = rs.getObject(column.values()); if(oValue!= null){ String fieldName = field.getName(); Method m = cls.getDeclaredMethod("set"+fieldName.substring(0,1).toUpperCase() +fieldName.substring(1),oValue.getClass()); m.invoke(t, oValue); } } } tList.add(t); } return tList; }