JAVA中List的增删改查

package com.collection.homework; public class Student implements Comparable{ private int id; private String name; private String sid; private int age; private String sex; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSid() { return sid; } public void setSid(String sid) { this.sid = sid; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Student(int id, String name, String sid, int age, String sex) { this.id = id; this.name = name; this.sid = sid; this.age = age; this.sex = sex; } public int hashCode() { final int prime = 31; int result = 1; result = prime * result + age; result = prime * result + id; result = prime * result + ((name == null) ? 0 : name.hashCode()); result = prime * result + ((sex == null) ? 0 : sex.hashCode()); result = prime * result + ((sid == null) ? 0 : sid.hashCode()); return result; } public boolean equals(Object obj) { if(obj == null){ return false; } if(obj instanceof Student){ Student s = (Student)obj; if(this.name.equals(s.getName()) && this.id == s.getId() && this.sid.equals(s.getSid()) && this.age == s.getAge() && this.sex.equals(s.getSex())){ return true; } } return false; } public int compareTo(Object obj) { Student s = (Student)obj; //先按NAME排序； if(this.name.compareTo(s.getName())>0) return 1; if(this.name.compareTo(s.getName())<0) return -1; //先按AGE排序； if(this.age>s.getAge()) return 1; if(this.age < s.getAge()) return -1; //先按sex排序； if(this.sex.compareTo(s.getSex())>0) return 1; if(this.sex.compareTo(s.getSex())<0) return -1; return 0; } }