Java List排序（包括对象List排序）

我不是女神ヾ 2022-07-14 01:44 196阅读 0赞

## 常见数据类型List ##

直接把需要排序的list当做参数调用下列方法即可

Collections.sort(list);//升序排列
    Collections.sort(list,Collections.reverseOrder());//降序排列

## 对象List ##

举例：

### Student.java（一个简单的实体类） ###

public class Student {
        private String id;
        private String stu_code;
        private String name;
        public Student(String id,String name,String stu_code) {
            // TODO Auto-generated constructor stub
            this.id=id;
            this.name=name;
            this.stu_code=stu_code;
        }
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getStu_code() {
            return stu_code;
        }
    
        public void setStu_code(String stu_code) {
            this.stu_code = stu_code;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    }

--------------------

### ComparatorStudent.java(可以把这个类理解为排序的辅助类) ###

public class ComparatorStudent implements Comparator {
        
    
        public int compare(Object obj1, Object obj2) {
        //需要什么样的实体类就把Student换成对应的即可
            Student stu0 = (Student) obj1;
            Student stu1 = (Student) obj2;
            //这里只需要改一下按什么属性排序即可
            int flag = stu0.getStu_code().compareTo(stu1.getStu_code());
            return flag;
        }
    }

### Main方法： ###

public static void main(String[] args) {
            // TODO Auto-generated method stub
    
    
            List<Student> stus=new ArrayList<Student>();
            stus.add(new Student("1", "zwq1", "20160001"));
            stus.add(new Student("3", "zwq3", "20160003"));
            stus.add(new Student("2", "zwq2", "20160002"));
    
            ComparatorStudent comparatorStudent=new ComparatorStudent();
            Collections.sort(stus,comparatorStudent);
            for(Student student:stus){
                System.out.println(student.getName());
            }
        }