java按等级，名称排序等级

Question

此代码的结果是将mergedGrades 移动到一个sortedGrades 中，该排序基于按等级排序，然后是名称。我设法找到从最高到最低的等级，但我无法按名称对等级进行排序。请帮忙。

我的代码：

        public static Grades sort(Grades mergedGrades, Grades repeat) {
          Grades sortedGrades = new Grades();
            while( (mergedGrades.size() > 0)){
            Grade highComp = null;
            Grade highest = mergedGrades.get(0);

            int index = 0;
            for (int j = 0; j < mergedGrades.size(); j++) {
                highComp = mergedGrades.get(j);
                if (highComp.getGpa() > highest.getGpa()) {
                    highest = highComp;
                }
            }
            //sortedGrades.add(highest);

            for(int i = 0 ; i < mergedGrades.size(); i++){
                       for (int i = 0; i < repeat.size(); i++) {
                if (repeat.contains(highest)) {
           if(highest.getFirstName().compareTo(repeat.get(i).getFirstName()) < 0) {
        if(mergedGrades.get(i).getLastName().compareTo(highest.getLastName()) < 0) {
                            sortedGrades.add(highest);
                            System.out.println("test");
                        }
                    }
                }
            }
            sortedGrades.add(highest);
            mergedGrades.remove(index);

        }

结果应该是这样的：

   S005: Stacy, Lu 4.0
   S004: Aseef, Hernandez 3.9
   S006: Aseef, Nilkund 3.9
   S002: Jim, NLN 3.9
   S003: Misty, Fang 3.9
   S009: Steve, Calderon 3.9
   S016: Aseef, Simmons 3.9
   S010: Raj, Singh 3.8
   S018: Hamza, Nilkund 3.5
   S012: Kathy, Calderon 3.5
   S017: Hifza, Nilkund 3.3
   S011: Jason, Kramer 3.3
   S001: John, Rodgers 3.3
   S019: Chris, Peach 3.2
   S013: Roopa, Singh 3.2
   S020: Ramona, Luke 2.4
   S014: Amid, Naveed 2.4
   S015: Faith, Williams 1.0

Answer 1

比较hashCode() 值不是对名称进行排序的方法。请改用compareTo()：

if (mergedGrades.get(i).getFirstName().compareTo(
            highest.getFirstName()) < 0) {
   // mergedGrades firstname < highest firstname
}