一 概念

最典型的例子是Department和Employee的关系，双向的关联

二 代码分析

（1）Department表

package com.hbsi.domain;

import java.util.Set;

//部门类

public class Department {

//实现一对多

private int id;

private String nameString;

private Set emps; //集合类型，因为有多个员工

public Department() {

super();

// TODO Auto-generated constructor stub

}

public Department(int id, String nameString, Set emps) {

super();

this.id = id;

this.nameString = nameString;

this.emps = emps;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getNameString() {

return nameString;

}

public void setNameString(String nameString) {

this.nameString = nameString;

}

public Set getEmps() {

return emps;

}

public void setEmps(Set emps) {

this.emps = emps;

}

@Override

public String toString() {

return "Department [id=" + id + ", nameString=" + nameString

+ ", emps=" + emps + "]";

}

}

（2）Employee类

package com.hbsi.domain;

//员工类 一般主鍵是建在多的一方

public class Employee {

private int id;

private String name;

//通过id查询员工，通过员工 查找部门的话，只能找到部门的id,得不到部门的其他信息

// 得到的是一个 对象，可以得到员工对应的部门的详细信息

private Department depart;

public Employee() {

super();

// TODO Auto-generated constructor stub

}

public Employee(int id, String name, Department depart) {

super();

this.id = id;

this.name = name;

this.depart = depart;

}

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 Department getDepart() {

return depart;

}

public void setDepart(Department depart) {

this.depart = depart;

}

public String toString() {

return "Employee [id=" + id + ", name=" + name + ", depart=" + depart

+ "]";

}

}

（3）配置文件