首先按照最近或即将到来的日期的顺序获取排序列表，然后根据今天的日期获取其余的列表

如果您创建两个排序列表，一个是即将到来的日期，另一个是已经过去的日期。然后首先用即将到来的日期和过去的日期填充第三个列表。:-

测试代码

package com.test;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;

public class TestCode {

    public static void main(String[] args) throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
        Date today = sdf.parse("18/10/2017");

        // assuming Dates - 3/10/2017 12/9/2017 20/10/2017 21/10/2017
        String dts = "3/10/2017,12/9/2017,20/10/2017,21/10/2017";

        List<AssignmentUpload> assignmentUploadList = new ArrayList<AssignmentUpload>();
        List<AssignmentUpload> futureAssg = new ArrayList<AssignmentUpload>();
        List<AssignmentUpload> pastAssg = new ArrayList<AssignmentUpload>();
        List<AssignmentUpload> finalAssg = new ArrayList<AssignmentUpload>();

        for (String dt : dts.split(",")) {

            String[] nos = dt.split("/");
            int day = Integer.parseInt(nos[0]);
            int mon = Integer.parseInt(nos[1]);
            int year = Integer.parseInt(nos[2]);

            AttendanceDate ad = new AttendanceDate(day,mon,year);
            AssignmentUpload au = new AssignmentUpload();
            au.setAttendanceDate(ad);
            au.setSubjectName("assg - " +dt);

            assignmentUploadList.add(au);

        }

        // Now we will start with assignmentUploadList

        for (AssignmentUpload au : assignmentUploadList) {

            int day = au.getAttendanceDate().getDay();
            int mon = au.getAttendanceDate().getMonth();
            int year = au.getAttendanceDate().getYear();

            Date date = sdf.parse(day+"/"+mon +"/"+year); 

            if (date.before(today)) {
                pastAssg.add(au);
            } else {
                futureAssg.add(au);
            }

        }

        // Sort pastand future dates individually
        Collections.sort(futureAssg);
        Collections.sort(pastAssg,Collections.reverseOrder());

        // Add future Dates to final Dates first
        finalAssg.addAll(futureAssg);


        // Then Add past Dates to final Dates
        finalAssg.addAll(pastAssg);

        assignmentUploadList = finalAssg;

        for (AssignmentUpload au : assignmentUploadList) {
            System.out.println(au.getSubjectName());
        }

    }

}

更新了 AssignmentUpload.java（使其具有可比性）

package com.test;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import com.test.AttendanceDate;

public class AssignmentUpload implements Comparable{

    private String fileName;
    private String url;
    private String year;
    private String title;

    private String instructions;
    private AttendanceDate attendanceDate;
    private String subjectName;
    private String uploadedBy;
    public String getFileName() {
        return fileName;
    }
    public void setFileName(String fileName) {
        this.fileName = fileName;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
    public String getYear() {
        return year;
    }
    public void setYear(String year) {
        this.year = year;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getInstructions() {
        return instructions;
    }
    public void setInstructions(String instructions) {
        this.instructions = instructions;
    }
    public AttendanceDate getAttendanceDate() {
        return attendanceDate;
    }
    public void setAttendanceDate(AttendanceDate attendanceDate) {
        this.attendanceDate = attendanceDate;
    }
    public String getSubjectName() {
        return subjectName;
    }
    public void setSubjectName(String subjectName) {
        this.subjectName = subjectName;
    }
    public String getUploadedBy() {
        return uploadedBy;
    }
    public void setUploadedBy(String uploadedBy) {
        this.uploadedBy = uploadedBy;
    }

    public int compareTo(Object o) {

        AssignmentUpload au = (AssignmentUpload)o;

        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");



        int day = attendanceDate.getDay();
        int mon = attendanceDate.getMonth();
        int year = attendanceDate.getYear();

        int oday = au.getAttendanceDate().getDay();
        int omon = au.getAttendanceDate().getMonth();
        int oyear = au.getAttendanceDate().getYear();

        try {
            Date date = sdf.parse(day+"/"+mon +"/"+year);
            Date odate = sdf.parse(oday+"/"+omon +"/"+oyear);

            return date.compareTo(odate);

        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return 0;
    }



}

输出： assg - 20/10/2017 assg - 21/10/2017 assg - 3/10/2017 assg - 12/9/2017