实战3--设计管理模块, 第5步,实体设计技巧

1. 设计实体:

1. 有几个实体? 一组增删改查对应一个实体

系统中的3个实体: department, role, user

2. 实体键的关系: 页面引用了其他实体, 那么就是和这个实体有关系

Department有上级和下级, 一对多

Department 1 ======> * User *======> * Role

3. 每个实体都有什么属性?

   1) 主键,  Long类型的id

   2) 关联关系属性

　　Department: Set<User>, Department parent, Set<Department> children.

　　User: Deparment department, Set<Role>

　　Role: Set<User>

　3) 一般属性: 分析相关的页面

      Department: id, name, description, Set<User>, Department parent, Set<Department> children

      User: id, name, password, loginName, gender(String), phoneNumber(String), email, description, Set<Role>, Department department.

   4) 特殊属性, 比如要显示年龄, 不设计int age, 而是一个Date birthday字段, 年龄是计算出来的.

写全每个实体类文件:

Department.java:

package cn.itcast.oa.domain;

import java.util.HashSet;
import java.util.Set;

public class Department {
	private Long id;
	private String name;
	private String description;
	private Department parent;
	private Set<Department> children = new HashSet<Department>();
	private Set<User> users = new HashSet<User>();
	
	
	public Long getId() {
		return id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	public Department getParent() {
		return parent;
	}
	public void setParent(Department parent) {
		this.parent = parent;
	}
	public Set<Department> getChildren() {
		return children;
	}
	public void setChildren(Set<Department> children) {
		this.children = children;
	}
	public Set<User> getUser() {
		return users;
	}
	public void setUser(Set<User> user) {
		this.users = user;
	}
}

 Role.java:

package cn.itcast.oa.domain;

import java.util.HashSet;
import java.util.Set;

public class Role {
	private Long id;
	private String name;
	private String description;
	private Set<User> users = new HashSet<User>();
	
	public Set<User> getUsers() {
		return users;
	}
	public void setUsers(Set<User> users) {
		this.users = users;
	}
	public Long getId() {
		return id;
	}
	public String getName() {
		return name;
	}
	public String getDescription() {
		return description;
	}
	public void setId(Long id) {
		this.id = id;
	}
	public void setName(String name) {
		this.name = name;
	}
	public void setDescription(String description) {
		this.description = description;
	}		
}

 User.java

package cn.itcast.oa.domain;

import java.util.HashSet;
import java.util.Set;

public class User {
	private long id;
	private String name;
	private String loginName;
	private String password;
	private String gender;
	private String phoneNumber;
	private String email;
	private String description;
	
	private Department department;
	private Set<Role> roles = new HashSet<Role>();
	
	
	public String getLoginName() {
		return loginName;
	}
	public void setLoginName(String loginName) {
		this.loginName = loginName;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public String getPhoneNumber() {
		return phoneNumber;
	}
	public void setPhoneNumber(String phoneNumber) {
		this.phoneNumber = phoneNumber;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	public Set<Role> getRoles() {
		return roles;
	}
	public void setRoles(Set<Role> roles) {
		this.roles = roles;
	}
	public Department getDepartment() {
		return department;
	}
	public void setDepartment(Department department) {
		this.department = department;
	}
	public long getId() {
		return id;
	}
	public void setId(long id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
}

 写配置文件:

1. 写注释: ?属性, 表达的是本对象与?的?关系

2. 拷 模板   

<!-- department属性, 本类与Department的  多对一 -->
<many-to-one name="" class="" column=""></many-to-one>

<!-- users属性, 本类与User的一对多 -->
<set name="">
	<key column=""></key>
	<one-to-many class=""/>
</set>

<!-- users属性, 本类与User的 多对多 -->
<set name="" table="">
	<key column=""></key>
	<many-to-many class="" column=""></many-to-many>
</set>

3. 填空:

    name属性: 属性名, 第1个?

    class属性: 关联的实体类型: 第2个?

　column属性:

         <many-to-one column="">: 关系里1的那个属性名Id, 比如departmentId

         一对多中<key column=""> : 从关联的一方映射中把column值拷过来. 上面的departmentId

         多对多中的<key column="">, 本对象名加Id, 如userId.

  注意: 一对多有两个表, 一个外键, 多对多有3个表, 2个外键.

 User->Department多对一模板:  name填写属性, class填写Department

外键在多的一方, 所以column写 属性Id:departmentId

<!-- department属性, 本类与Department的  多对一 -->
<many-to-one name="department" class="Department" column="departmentId"></many-to-one>

 Department->User 一对多模板:  name填写属性users     class填写User

column也上面多对一的那个departmentId

<!-- users属性, 本类与User的一对多 -->
<set name="users">
	<key column="departmentId"></key>
	<one-to-many class="User"/>
</set>

Role->User 多对多模板: name填users,  class填User

                  table写itcast_user_role,  key column写 roleId, many-to-many写 userId

<!-- users属性, 本类与User的 多对多 -->
<set name="users" table="itcast_user_role">
	<key column="roleId"></key>
	<many-to-many class="User" column="userId"></many-to-many>
</set>

User->Role多对多模板:  name填roles,  class填Role

　　　　 table和上面一样写itcast_user_role,  key column写 userId, many-to-many写 roleId

<!-- roles属性, 本类与Role的  多对多 -->
<set name="roles" table="itcast_user_role">
	<key column="userId"></key>
	<many-to-many class="Role" column="roleId"></many-to-many>
</set>

Department.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="cn.itcast.oa.domain">
	<class name="Department" table="itcast_department">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" />
		<property name="description" />
		<!-- users属性, 本类与User的一对多 -->
		<set name="users">
			<key column="departmentId"></key>
			<one-to-many class="User"/>
		</set>
		<!-- parent属性, 本类与Department上级的多对一 -->
		<many-to-one name="parent" class="Department" column="parentId"></many-to-one>
		<!-- children属性, 本类与下级Department的一对多 -->
		<set name="children">
			<key column="parentId"></key>
			<one-to-many class="Department"/>
		</set>
	</class>
</hibernate-mapping>

 Role.hbm.xml:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="cn.itcast.oa.domain">
	<class name="Role" table="itcast_role">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" />
		<property name="description" />
		<!-- users属性, 本类与User的 多对多 -->
		<set name="users" table="itcast_user_role">
			<key column="roleId"></key>
			<many-to-many class="User" column="userId"></many-to-many>
		</set>
	</class>
</hibernate-mapping>

 User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="cn.itcast.oa.domain">
	<class name="User" table="itcast_user">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" />
		<property name="loginName" />
		<property name="password" />
		<property name="gender" />
		<property name="phoneNumber" />
		<property name="email" />
		<property name="description" />
		<!-- department属性, 本类与Department的  多对一 -->
		<many-to-one name="department" class="Department" column="departmentId"></many-to-one>
		
		<!-- roles属性, 本类与Role的  多对多 -->
		<set name="roles" table="itcast_user_role">
			<key column="userId"></key>
			<many-to-many class="Role" column="roleId"></many-to-many>
		</set>
	</class>
</hibernate-mapping>