怎么按成绩降序输出学生姓名 RT 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 select * from students order by score desc" order by score desc按照学生成绩降序排列 order by 成绩 desc 汗哒哒滴……我在JAVA区问,为什么都用SQL回答…… Student类实现Comparable接口,重写compareTo(Object obj)方法,return this.name.compareTo(((Student)obj).getName());然后用Collections.sort(Collection c);就排好序了.当然也可以写个比较器, 然后把学生都扔进TreeSet或者TreeMap也可以简单排序 因为很少有人用java做这个,放在数据库里做多方便? 不知你是何数据结构,如果就姓名和成绩的话用个基本的hashmap就可以了,完后排个序就行了 (⊙o⊙)… 看错了,我写了name了,反正一样,领会就好 ⊙﹏⊙b汗 ⊙﹏⊙b汗 降序的话把compareTo的前后项颠倒一下 public static void main (String [] args) { List<Student> list=new ArrayList<Student>(); list.add(new Student(90,"aaa")); list.add(new Student(100,"bbb")); list.add(new Student(72,"ccc")); list.add(new Student(83,"ddd")); list.add(new Student(91,"eee")); list.add(new Student(60,"fff")); Collections.sort(list,new Comparator<Student>(){ public int compare(Student sa, Student sb) { if(sa.getScore()>sb.getScore()) return 1; else if(sa.getScore()==sb.getScore()) return 0; else return -1; } }); for(Students:list) System.out.println(s.getName()+":"+s.getScore()); }student:class Student { private int score; private String name; public SortArray(int score,String name){ this.score=score; this.name=name; } public int getScore() { return score; } public void setScore(int score) { this.score = score; } public String getName() { return name; } public void setName(String name) { this.name = name; } } public Student(int score,String name){ this.score=score; this.name=name;} 一句sql 就能解决问题。呵呵 sql多简单啊纯java写麻烦 java 垃圾回收 java中Thread.activeCount()/Thread.currentThread()好像并不能统计嵌套的线程数 发现一个有趣的现象,希望高人能够解释 菜鸟问题 0x01<<8+0x3f 与 (0x01<<8)+0x3f 为什么结果不一样? 为何上传文件后在服务器端无法删除此文件 请教一个线程和GUI合用的问题? 怎样获取某一数据库中的所有表??(在线等待) 请问如何计算查询出来的资料的行数 在JBuilder中窗体的什么事件与Delphi中的窗体的CloseQuery事件相同? 加载dll失败,给出出错信息,大家帮我看看。 构造函数
select * from students order by score desc" order by score desc
按照学生成绩降序排列
然后用Collections.sort(Collection c);就排好序了.当然也可以写个比较器, 然后把学生都扔进TreeSet或者TreeMap也可以简单排序
public static void main (String [] args)
{
List<Student> list=new ArrayList<Student>();
list.add(new Student(90,"aaa"));
list.add(new Student(100,"bbb"));
list.add(new Student(72,"ccc"));
list.add(new Student(83,"ddd"));
list.add(new Student(91,"eee"));
list.add(new Student(60,"fff"));
Collections.sort(list,new Comparator<Student>(){
public int compare(Student sa, Student sb) {
if(sa.getScore()>sb.getScore())
return 1;
else if(sa.getScore()==sb.getScore())
return 0;
else return -1;
}
});
for(Students:list)
System.out.println(s.getName()+":"+s.getScore());
}
student:class Student
{
private int score;
private String name;
public SortArray(int score,String name){
this.score=score;
this.name=name;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
this.score=score;
this.name=name;
}
纯java写麻烦