java排序

    public static <E> void sort(List<E> list, final String method, final String sort) {
        Comparator<E> comparator = new Comparator<E>() {

            public int compare(E a, E b) {
                int ret = 0;

                try {
                    Method m1 = (a).getClass().getMethod(method);
                    Method m2 = (b).getClass().getMethod(method);
                    Object valueB = m2.invoke(b);
                    Object valueA = m1.invoke(a);

                    Method compareTo = valueB.getClass().getMethod("compareTo", valueA.getClass());
                    if (sort != null && "desc".equals(sort)) {
                        // 倒序
                        ret = (int) compareTo.invoke(valueB, valueA);
                    } else {
                        // 正序
                        ret = (int) compareTo.invoke(valueA, valueB);
                    }
                } catch (NoSuchMethodException ne) {
                    logger.error("NoSuchMethod", ne);
                } catch (IllegalAccessException ie) {
                    logger.error("IllegalAccess", ie);
                } catch (InvocationTargetException it) {
                    logger.error("InvocationTarget", it);
                }

                return ret;
            }
        };

        Collections.sort(list, comparator);
    }

 

     通用，但三次反射损耗不少

 

     优化之后：

 

        public static <E> void sort(List<E> list, final String method, final String sort) {
        Comparator<E> comparator = new Comparator<E>() {

            public int compare(E a, E b) {
                int ret = 0;

                try {
                    Method m1 = (a).getClass().getMethod(method);
                    Method m2 = (b).getClass().getMethod(method);
                    Object valueB = (Object)m2.invoke(b);
                    Object valueA = (Object)m1.invoke(a);

                    if (sort != null && "desc".equals(sort)) {
                        // 倒序
                        ret = (int) ((Comparable<Object>) valueB).compareTo(valueA);
                    } else {
                        // 正序
                        ret = (int) ((Comparable<Object>) valueA).compareTo(valueB);
                    }
                } catch (NoSuchMethodException ne) {
                    logger.error("NoSuchMethod", ne);
                } catch (IllegalAccessException ie) {
                    logger.error("IllegalAccess", ie);
                } catch (InvocationTargetException it) {
                    logger.error("InvocationTarget", it);
                }

                return ret;
            }
        };

        Collections.sort(list, comparator);
    }