吴裕雄--天生自然java开发常用类库学习笔记：一对多关系范例

import java.util.List ;
import java.util.ArrayList ;
public class School{
    private String name ;
    private List<Student> allStudents ;
    public School(){
        this.allStudents = new ArrayList<Student>() ;
    }
    public School(String name){
        this() ;
        this.setName(name) ;
    }
    public void setName(String name){
        this.name = name ;
    }
    public String getName(){
        return this.name; 
    }
    public List<Student> getAllStudents(){
        return this.allStudents ;
    }
    public String toString(){
        return "学校名称：" + this.name ;
    }
};

public class Student{
    private String name ;
    private int age ;
    private School school; // 一个学生属于一个学校
    public Student(String name,int age){
        this.setName(name) ;
        this.setAge(age) ;
    }
    public void setSchool(School school){
        this.school = school ;
    }
    public School getSchool(){
        return this.school ;
    }
    public void setName(String name){
        this.name = name ;
    }
    public void setAge(int age){
        this.age = age ;
    }
    public String getName(){
        return this.name; 
    }
    public int getAge(){
        return this.age ;
    }
    public String toString(){
        return "学生姓名：" + this.name + "；年龄：" + this.age ;
    }
};

import java.util.Iterator ;
public class TestDemo{
    public static void main(String args[]){
        School sch = new School("清华大学") ;    // 定义学校
        Student s1 = new Student("张三",21) ;
        Student s2 = new Student("李四",22) ;
        Student s3 = new Student("王五",23) ;
        sch.getAllStudents().add(s1) ;
        sch.getAllStudents().add(s2) ;
        sch.getAllStudents().add(s3) ;
        s1.setSchool(sch) ;
        s2.setSchool(sch) ;
        s3.setSchool(sch) ;
        System.out.println(sch) ;
        Iterator<Student> iter = sch.getAllStudents().iterator() ;
        while(iter.hasNext()){
            System.out.println("\t|- " + iter.next()) ;
        }
    }
};