多字段 java对象排序

public class ReflexUtil {
static Logger logger = LoggerFactory.getLogger(ReflexUtil.class);

//getMethod
static public Object invokeMethod(String propertiesName, Object object) {
try {
if(object==null) return null;
if (!propertiesName.contains(".")) {
String methodName = "get"+getMethodName(propertiesName);
Method method = object.getClass().getMethod(methodName);
return method.invoke(object);
}
String methodName = "get"+getMethodName(propertiesName.substring(0,propertiesName.indexOf(".")));
Method method = object.getClass().getMethod(methodName);
return invokeMethod(propertiesName.substring(propertiesName.indexOf(".")+1), method.invoke(object));

} catch (Exception e) {
logger.error(e.toString(), e);
return null;
}
}

private static String getMethodName(String fildeName) {
byte[] items = fildeName.getBytes();
items[0] = (byte) ((char) items[0] - 'a' + 'A');
return new String(items);
}

public static void main(String args[]) {
Video video = new Video();
Album album = new Album();
album.setAlbumId(346l);
video.setAlbum(album);
video.setVideoId(126l);
System.out.println(ReflexUtil.invokeMethod("album.albumId", video));
}
}

public class CompareUtil {
 
    //sort 1正序 -1 倒序  filed 多字段排序
    public static <t> Comparator createComparator(int sort, String... filed) {
        return new ImComparator(sort, filed);
    }
 
    public static class ImComparator implements Comparator {
        int sort = 1;
        String[] filed;
 
        public ImComparator(int sort, String... filed) {
            this.sort = sort == -1 ? -1 : 1;
            this.filed = filed;
        }
 
        @Override
        public int compare(Object o1, Object o2) {
            int result = 0;
            for (String file : filed) {
                Object value1 = ReflexUtil.invokeMethod(file, o1);
                Object value2 = ReflexUtil.invokeMethod(file, o2);
                if (value1 == null || value2 == null) {
                    continue;
                }
                if (!(value1 instanceof Integer) || !(value1 instanceof Integer)) {
                    continue;
                }
                int v1 = Integer.valueOf(value1.toString());
                int v2 = Integer.valueOf(value2.toString());
                if (v1 == v2) continue;
                if (sort == 1) {
                    return v1 - v2;
                } else if (sort == -1) {
                    return v2 - v1;
                } else {
                    continue;
                }
            }
            return result;
        }
    }
 
    public static void main(String args[]) {
        LabelAlbum label1 = new LabelAlbum();
        label1.setLabelId(1); label1.setSequnces(1);
        LabelAlbum label2 = new LabelAlbum();
        label2.setLabelId(1);label2.setSequnces(2);
        LabelAlbum label3 = new LabelAlbum();
        label3.setLabelId(3); label3.setSequnces(4);
        LabelAlbum label4 = new LabelAlbum();
        label4.setLabelId(3);label4.setSequnces(3);
        LabelAlbum label5 = new LabelAlbum();
        label5.setLabelId(4);label5.setSequnces(2);
        List<labelalbum> list = new ArrayList<labelalbum>();
        list.add(label1);
        list.add(label2);
        list.add(label3);
        list.add(label4);
        list.add(label5);
        Collections.sort(list, CompareUtil.createComparator(1, "labelId","sequnces"));
        for (int i = 0; i < list.size(); i++) {
            LabelAlbum labelAlbum=list.get(i);
            System.out.println("labelId:"+labelAlbum.getLabelId()+"  sequence:"+labelAlbum.getSequnces());
        }
    }
}</labelalbum></labelalbum></t>
原文地址:https://www.cnblogs.com/ctaixw/p/5268780.html