按属性取方法名 java反射

最新推荐文章于 2023-04-22 11:21:27 发布

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本文介绍了一种使用Java对列表进行排序并设置排名的方法。该方法通过获取特定的getter方法来实现对列表中对象属性的数值排序，并考虑了空值的情况。排序完成后，还会根据排名设置setter方法为列表中的每个元素分配排名。


 //排序排名
        sortGDTownIndex(result, "ForeignComplete", "ForeignCompleteNum");

    Method ms = null;//比较接口是要用到全局变量
    private void sortGDTownIndex(List result, String get, String set) {


        Class c = ((GDTempTownIndex) result.get(0)).getClass();
        Method[] mss = c.getMethods();
        for (int i = 0; i < mss.length; i++) {
            Method m = mss[i];
            String name = m.getName();
            if (name.startsWith("get") && name.endsWith(get)) {
                ms = m;
                break;
            }
        }
        //过滤空的值
        List addList = new ArrayList();
        System.out.println("1result.size()=" + result.size());
        System.out.println("mse()=" + ms.getName());
        for (int i = 0; i < result.size(); i++) {
            GDTempTownIndex t = (GDTempTownIndex) result.get(i);
            try {
//                 System.out.println("t.name="+t.getTownName());
//                  System.out.println("t.ms="+ms.getName());
                System.out.println("t.value=" + ms.invoke(t));
                if (ms.invoke(t) == null) {
                    addList.add(t);
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
        result.removeAll(addList);
        System.out.println("==result.size()=" + result.size());
        System.out.println("addList.size()=" + addList.size());
        Comparator comp = new Comparator() {
            @Override
            public int compare(Object o1, Object o2) {
                GDTempTownIndex p1 = (GDTempTownIndex) o1;
                GDTempTownIndex p2 = (GDTempTownIndex) o2;
                int i = -1;
                try {
                    if ((Double) ms.invoke(p1) < ((Double) ms.invoke(p2))) {
                        i = 1;
                    } else if ((Double) ms.invoke(p1) > ((Double) ms.invoke(p2))) {
                        i = -1;
                    }
                } catch (Exception ex) {
                    ex.printStackTrace();
                } finally {
                    return i;
                }
            }
        };
        //排序
        System.out.println("=============is=");
        if (result.size() != 0) {
            Collections.sort(result, comp);

        }
        for (int i = 0; i < mss.length; i++) {
            Method m = mss[i];
            String name = m.getName();
            if (name.startsWith("set") && name.endsWith(set)) {
                ms = m;
            }
        }
        //设置排名
        try {
            for (int i = 0; i < result.size(); i++) {
                GDTempTownIndex t = (GDTempTownIndex) result.get(i);
                ms.invoke(t, new Double(String.valueOf(i + 1)));
            }
            result.addAll(addList);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }