java中arraylist對象排序程式

代碼如下

複製代碼

import java.util.ArrayList;    import java.util.Collection;    import java.util.Collections;    import java.util.Comparator;          public class SortTwo implements Comparator {    //排序欄位    private String sort1;    //排序方式    private int state;    public SortTwo(int state){    this.state=state;    }    public SortTwo(){       }    public int SortUp(Object o1,Object o2){    Student stu=(Student) o1;    Student stu1=(Student) o2;    if(sort1.equals("name")){    if(stu.getName().compareTo(stu1.getName())>1){    return 1;    } else if(stu.getName().compareTo(stu1.getName())<1){    return -1;    }else{    return 0;    }    }    if(sort1.equals("age")){    if(stu.getAge().compareTo(stu1.getAge())>1){    return 1;    } else if(stu.getAge().compareTo(stu1.getAge())<1){    return -1;    }else{    return 0;    }    }    return 0;    }    public int SortDOWN(Object o1,Object o2){    Student stu=(Student) o1;    Student stu1=(Student) o2;    if(sort1.equals("name")){    if(stu.getName().compareTo(stu1.getName())>1){    return -1;    } else if(stu.getName().compareTo(stu1.getName())<1){    return 1;    }else{    return 0;    }    }    if(sort1.equals("age")){    if(stu.getAge().compareTo(stu1.getAge())>1){    return -1;    } else if(stu.getAge().compareTo(stu1.getAge())<1){    return 1;    }else{    return 0;    }    }    return 0;    }    public int compare(Object o1, Object o2) {       if(this.state==1){    return SortUp(o1, o2);    }else{    return SortDOWN(o1, o2);    }    }       /**   * @param args   */   public static void main(String[] args) {    // TODO Auto-generated method stub    Student stu=new Student();    stu.setName("123");    stu.setAge("12");    Student stu1=new Student();    stu1.setName("234");    stu1.setAge("23");    ArrayList<Student>list=new ArrayList<Student>();    list.add(stu);    list.add(stu1);    SortTwo t=new SortTwo(1);    t.sort1="age";    Collections.sort(list,t);    for(Student st : list){    System.out.println(st.getName() +"   "+st.getAge());    }    }       }