java实现按对象某个字段排序，排序字段和规则自定义

Posted 2021-01-11 奋小斗Struggle Young

@SuppressWarnings({ "unchecked", "rawtypes" })
private <T> void sort(List<T> targetList, final String sortField, final String sortMode) {
    Collections.sort(targetList, new Comparator() {
        //匿名内部类，重写compare方法
        @Override
        public int compare(Object obj1, Object obj2) {
                Class c = obj1.getClass();
                Integer result = 0;
                try {
                    Field field = c.getDeclaredField(sortField);
                    String classType = field.getType().getSimpleName();
                    Method method = null;
                    if (BIGDECIMAL.equals(classType)) {
                        method = c.getMethod("get" + sortField.substring(0, 1).toUpperCase() + sortField.substring(1), new Class[]{});
                        if (BizConstants.DESC.equalsIgnoreCase(sortMode)) {
                            result = ((BigDecimal) method.invoke(obj2)).compareTo((BigDecimal) method.invoke(obj1));
                        } else if (BizConstants.DESC.equalsIgnoreCase(sortMode)) {
                            result = ((BigDecimal) method.invoke(obj1)).compareTo((BigDecimal) method.invoke(obj2));
                        }
                    } else {
                        result = -100;
                        throw new RuntimeException("暂不支持其它类型字段排序,如有需要请自己添加.");
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            return result > 0 ? 1 : result < 0 ? -1 : 0;
        }
    });
}