JavaWeb_(Hibernate框架)Hibernate论坛项目中一对多案例
基于SSH论坛小型项目 传送门
用户和发帖进行举例
一对多关系：一个用户可以发表多个帖子
一对一关系：一个帖子属于一个用户发布
创建数据库用户user表
CREATE TABLE `hforum`.`user` (
`id` VARCHAR(50) NOT NULL,
`username` VARCHAR(45) NULL,
`password` VARCHAR(45) NULL,
`name` VARCHAR(45) NULL,
`email` VARCHAR(45) NULL,
`telephon` VARCHAR(45) NULL,
PRIMARY KEY (`id`));
Gary.sql
创建数据库帖子paste表
CREATE TABLE `hforum`.`paste` (
`id` VARCHAR(50) NOT NULL,
`title` VARCHAR(200) NULL,
`content` VARCHAR(255) NULL,
`offer` INT NULL,
`ansnum` INT NULL,
`glancover` INT NULL,
`createtime` VARCHAR(45) NULL,
`userid` VARCHAR(50) NULL,
PRIMARY KEY (`id`));
paste.sql
用户登陆：用户登陆成功，用户将从login.jsp跳转到index.jsp，用户登陆失败，将重定向到login.jsp
数据库中添加一条假数据
package com.Gary.dao; import org.hibernate.Session;
import org.hibernate.query.NativeQuery; import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils; public class UserDao { //原生SQL查询
public User findUesr(User user) { Session session = HibernateUtils.getCurrentSession();
String sql = "select * from user where username = ? and password = ?";
NativeQuery query = session.createSQLQuery(sql);
query.setParameter(1, user.getUsername());
query.setParameter(2, user.getPassword());
query.addEntity(User.class); User temp = (User) query.uniqueResult(); return temp; } }
UserDao.java
package com.Gary.domain;
public class Paste {
private String id;
private String title;
private String content;
private Integer offer;
private Integer ansnum;
private Integer glanceover;
private String createtime;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public Integer getOffer() {
return offer;
}
public void setOffer(Integer offer) {
this.offer = offer;
}
public Integer getAnsnum() {
return ansnum;
}
public void setAnsnum(Integer ansnum) {
this.ansnum = ansnum;
}
public Integer getGlanceover() {
return glanceover;
}
public void setGlanceover(Integer glanceover) {
this.glanceover = glanceover;
}
public String getCreatetime() {
return createtime;
}
public void setCreatetime(String createtime) {
this.createtime = createtime;
}
}
Paste.java
package com.Gary.domain;
public class User {
private String id;;
private String username;
private String password;
private String name;
private String email;
private String telephone;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getTelephone() {
return telephone;
}
public void setTelephone(String telephone) {
this.telephone = telephone;
}
}
User.java
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="com.Gary.domain">
<class name="User" table="user">
<id name = "id">
<generator class="uuid"></generator>
</id> <property name="username" column="username"></property>
<property name="password" column="password"></property>
<property name="name" column="name"></property>
<property name="email" column="email"></property>
<property name="telephone" column="telephone"></property> </class> </hibernate-mapping>
User.hbm.xml
package com.Gary.service; import org.hibernate.Transaction; import com.Gary.dao.UserDao;
import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils; public class UserService { public boolean findUesr(User user) { UserDao userDao = new UserDao();
//开启事务(查询不需要数据库保护)
Transaction transaction = HibernateUtils.getCurrentSession().beginTransaction(); User temp = null; try
{
temp = userDao.findUesr(user);
}
catch(Exception e)
{
transaction.rollback();
} //提交事务
transaction.commit(); return temp==null?false:true;
} }
UserService.java
package com.Gary.utils; import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration; public class HibernateUtils { private static SessionFactory sessionFactory = null; static {
Configuration config = new Configuration().configure();
sessionFactory = config.buildSessionFactory();
} public static Session getSession()
{
return sessionFactory.openSession();
} public static Session getCurrentSession()
{
return sessionFactory.getCurrentSession();
} }
HibernateUtils.java
package com.Gary.web; import com.Gary.domain.User;
import com.Gary.service.UserService;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven; public class UserAction extends ActionSupport implements ModelDriven<User>{ public User user = new User(); public String login() throws Exception { UserService userService = new UserService(); boolean success = userService.findUesr(user); System.err.println(success);
System.err.println(user.getUsername());
System.err.println(user.getPassword()); if(success)
{
return "toIndex";
}
else
{
ActionContext.getContext().put("error", "用户名或密码错误！！");
return "login";
} } @Override
public User getModel() {
// TODO Auto-generated method stub
return user;
} }
UserAction.java
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql:///hforum</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">123456</property> <!-- 将hibernate生成的sql语句打印到控制台 -->
<property name="hibernate.show_sql"></property> <!-- 格式化hibernate生成的sql语句 -->
<property name="hibernate.format_sql"></property> <!-- 配置hibernate自动创建表-->
<property name="hibernate.hbm2ddl.auto">update</property> <!-- 配置数据库的隔离级别-->
<property name="hibernate.connection.isolation">4</property> <!-- 配置事务 (session与当前线程绑定) -->
<property name="hibernate.current_session_context_class">thread</property> <mapping resource="com/Gary/domain/User.hbm.xml"/> </session-factory> </hibernate-configuration>
hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd"> <struts> <constant name="struts.devMode" value="true"></constant>
<constant name="struts.enable.DynamicMethodInvocation" value="true"></constant> <package name="hibernateTest" namespace="/" extends="struts-default">
<global-allowed-methods>regex:.*</global-allowed-methods>
<action name="UserAction_*" class="com.Gary.web.UserAction" method="{1}"> <result name="toIndex" type="redirect">/index.jsp</result>
<result name = "login">/login.jsp</result>
</action> </package> </struts>
struts.xml
用户发布帖子
一个用户可以发多个帖子，一个帖子对应一个用户
数据库中的用户
当用户登陆成功后，跳转至index.jsp首页面，用户可以进行发帖
package com.Gary.dao; import org.hibernate.Session; import com.Gary.domain.Paste;
import com.Gary.utils.HibernateUtils; public class PasteDao { public void addPaste(Paste paste) { Session session = HibernateUtils.getCurrentSession();
session.save(paste); } }
PasteDao.java
package com.Gary.dao; import org.hibernate.Session;
import org.hibernate.query.NativeQuery; import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils; public class UserDao { //原生SQL查询
public User findUesr(User user) { Session session = HibernateUtils.getCurrentSession();
String sql = "select * from user where username = ? and password = ?";
NativeQuery query = session.createSQLQuery(sql);
query.setParameter(1, user.getUsername());
query.setParameter(2, user.getPassword());
query.addEntity(User.class); User temp = (User) query.uniqueResult(); return temp; } }
UserDao.java
package com.Gary.domain;
public class Paste {
private String id;
private String title;
private String content;
private Integer offer;
private Integer ansnum;
private Integer glanceover;
private String createtime;
//一个帖子属于一个用户
private User user;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public Integer getOffer() {
return offer;
}
public void setOffer(Integer offer) {
this.offer = offer;
}
public Integer getAnsnum() {
return ansnum;
}
public void setAnsnum(Integer ansnum) {
this.ansnum = ansnum;
}
public Integer getGlanceover() {
return glanceover;
}
public void setGlanceover(Integer glanceover) {
this.glanceover = glanceover;
}
public String getCreatetime() {
return createtime;
}
public void setCreatetime(String createtime) {
this.createtime = createtime;
}
}
Paste.java
package com.Gary.domain; import java.util.HashSet;
import java.util.Set; public class User { private String id;;
private String username;
private String password; private String name;
private String email;
private String telephone; //一对多
private Set<Paste> pasteSet = new HashSet<Paste>(); public Set<Paste> getPasteSet() {
return pasteSet;
}
public void setPasteSet(Set<Paste> pasteSet) {
this.pasteSet = pasteSet;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getTelephone() {
return telephone;
}
public void setTelephone(String telephone) {
this.telephone = telephone;
} }
User.java
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="com.Gary.domain">
<class name = "Paste" table="paste">
<id name="id">
<generator class="uuid"></generator>
</id> <property name="title" column="title"></property>
<property name="content" column="content"></property>
<property name="offer" column="offer"></property>
<property name="ansnum" column="ansnum"></property>
<property name="glanceover" column="glanceover"></property>
<property name="createtime" column="createtime"></property> <!-- name:引用属性名
class:与他关系的对象的完整类名
column:外键列名
-->
<!-- inverse:配置关系是否不维护
true: 不维护
false: 维护关系
insert属性:
性能优化:
无论怎么放弃维护,总有一方需要维护(按照默认值来就行)
一般的开发中,一的一方放弃维护,多的一方不放弃维护
--> <!--
<many-to-one name="user" class="User" column="userid" cascade="save-update,persist"></many-to-one>
--> <many-to-one name="user" class="User" column="userid" ></many-to-one> </class> </hibernate-mapping>
Paste.xml.hbm
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="com.Gary.domain">
<class name="User" table="user">
<id name = "id">
<generator class="uuid"></generator>
</id> <property name="username" column="username"></property>
<property name="password" column="password"></property>
<property name="name" column="name"></property>
<property name="email" column="email"></property>
<property name="telephone" column="telephone"></property> <!-- name:集合属性名字
column:外键列名
class:与他相关的对象的完整类名 -->
<!--
cascade:级联操作
save-update:级联保存,级联更新
delete:级联删除
all
-->
<!-- inverse:配置关系是否不维护
true: 不维护
false: 维护关系
-->
<set name="pasteSet">
<key column="userid"></key>
<one-to-many class="Paste"/>
</set> </class> </hibernate-mapping>
User.hbm.xml
package com.Gary.service; import org.hibernate.Transaction; import com.Gary.dao.PasteDao;
import com.Gary.domain.Paste;
import com.Gary.utils.HibernateUtils; public class PasteService { public void addPaste(Paste paste) { PasteDao pasteDao = new PasteDao(); Transaction beginTransaction = HibernateUtils.getCurrentSession().beginTransaction(); try
{
pasteDao.addPaste(paste);
}
catch(Exception e)
{
beginTransaction.rollback();
} beginTransaction.commit();
} }
PasteService.java
package com.Gary.service; import org.hibernate.Transaction; import com.Gary.dao.UserDao;
import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils; public class UserService { public User findUesr(User user) { UserDao userDao = new UserDao();
//开启事务(查询不需要数据库保护)
Transaction transaction = HibernateUtils.getCurrentSession().beginTransaction(); User temp = null; try
{
temp = userDao.findUesr(user);
}
catch(Exception e)
{
transaction.rollback();
} //提交事务
transaction.commit(); return temp;
} }
UserService.java
package com.Gary.utils; import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration; public class HibernateUtils { private static SessionFactory sessionFactory = null; static {
Configuration config = new Configuration().configure();
sessionFactory = config.buildSessionFactory();
} public static Session getSession()
{
return sessionFactory.openSession();
} public static Session getCurrentSession()
{
return sessionFactory.getCurrentSession();
} }
HibernateUtils.java
package com.Gary.web; import java.text.SimpleDateFormat;
import java.util.Date; import com.Gary.domain.Paste;
import com.Gary.domain.User;
import com.Gary.service.PasteService;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven; public class PasteAction extends ActionSupport implements ModelDriven<Paste>{ public Paste paste = new Paste(); //addPaste
public String addPaste() throws Exception { //没有的数据手动封装
//title content offer
paste.setAnsnum(0);
paste.setGlanceover(0);
Date date = new Date(System.currentTimeMillis());
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String createtime = format.format(date);
paste.setCreatetime(createtime);
User user = (User) ActionContext.getContext().getSession().get("user");
paste.setUser(user); PasteService pasteService = new PasteService();
pasteService.addPaste(paste); return "toIndex";
} @Override
public Paste getModel() { return paste;
} }
PasteAction.java
package com.Gary.web; import com.Gary.domain.User;
import com.Gary.service.UserService;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven; public class UserAction extends ActionSupport implements ModelDriven<User>{ public User user = new User(); public String login() throws Exception { UserService userService = new UserService(); User temp = userService.findUesr(user); if(temp!=null)
{
ActionContext.getContext().getSession().put("user", temp);
return "toIndex";
}
else
{
ActionContext.getContext().put("error", "用户名或密码错误！！");
return "login";
} } @Override
public User getModel() {
// TODO Auto-generated method stub
return user;
} }
UserAction.java
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql:///hforum</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">123456</property> <!-- 将hibernate生成的sql语句打印到控制台 -->
<property name="hibernate.show_sql"></property> <!-- 格式化hibernate生成的sql语句 -->
<property name="hibernate.format_sql"></property> <!-- 配置hibernate自动创建表-->
<property name="hibernate.hbm2ddl.auto">update</property> <!-- 配置数据库的隔离级别-->
<property name="hibernate.connection.isolation">4</property> <!-- 配置事务 (session与当前线程绑定) -->
<property name="hibernate.current_session_context_class">thread</property> <mapping resource="com/Gary/domain/User.hbm.xml"/>
<mapping resource="com/Gary/domain/Paste.hbm.xml"/> </session-factory> </hibernate-configuration>
hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd"> <struts> <constant name="struts.devMode" value="true"></constant>
<constant name="struts.enable.DynamicMethodInvocation" value="true"></constant> <package name="hibernateTest" namespace="/" extends="struts-default">
<global-allowed-methods>regex:.*</global-allowed-methods>
<action name="UserAction_*" class="com.Gary.web.UserAction" method="{1}"> <result name="toIndex" type="redirect">/index.jsp</result>
<result name = "login">/login.jsp</result>
</action> <action name="PasteAction_*" class="com.Gary.web.PasteAction" method="{1}">
<result name="toIndex" type="redirect">/index.jsp</result>
</action> </package> </struts>
struts.xml
级联操作：级联（cascade）在计算机科学里指多个对象之间的映射关系，建立数据之间的级联关系提高管理效率
hibernate-mapping package="com.Gary.domain">
<class name="User" table="user">
<id name = "id">
<generator class="uuid"></generator>
</id> <property name="username" column="username"></property>
<property name="password" column="password"></property>
<property name="name" column="name"></property>
<property name="email" column="email"></property>
<property name="telephone" column="telephone"></property> <!-- name:集合属性名字
column:外键列名
class:与他相关的对象的完整类名 -->
<!--
cascade:级联操作
save-update:级联保存,级联更新
delete:级联删除
all
-->
<!-- inverse:配置关系是否不维护
true: 不维护
false: 维护关系
--> <set name="pasteSet">
<key column="userid"></key>
<one-to-many class="Paste"/>
</set> </class> </hibernate-mapping>
inverse操作
<hibernate-mapping package="com.Gary.domain">
<class name = "Paste" table="paste">
<id name="id">
<generator class="uuid"></generator>
</id> <property name="title" column="title"></property>
<property name="content" column="content"></property>
<property name="offer" column="offer"></property>
<property name="ansnum" column="ansnum"></property>
<property name="glanceover" column="glanceover"></property>
<property name="createtime" column="createtime"></property> <!-- name:引用属性名
class:与他关系的对象的完整类名
column:外键列名
-->
<!-- inverse:配置关系是否不维护
true: 不维护
false: 维护关系
insert属性:
性能优化:
无论怎么放弃维护,总有一方需要维护(按照默认值来就行)
一般的开发中,一的一方放弃维护,多的一方不放弃维护
--> <many-to-one name="user" class="User" column="userid" ></many-to-one> </class> </hibernate-mapping>
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