Spring MVC + Hibernate + Maven: Crud操作示例

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关于作者(Alexey Zvolinskiy)

Alexey是一个在使用Java,TestNG 和Selenium的自动化WEB应用程序中有丰富经验的测试开发者。他如此的喜欢QA以至于在下班后他为初级QA工程师提供培训课程。

在这篇文章中我想介绍一个Spring MVC + Hibernate + Maven例子。这组技术主要涉及一些基础知识,我想在每一个必要的地方详细解释它。本篇话题范围以外的更多资源,我会提供链接方便你阅读。在文章的最后,我将发布一个GitHub的链接。

目标

示例web应用程序是基于Spring MVC, Hibernate, Maven的,界面是基于HTML的。这个应用程序将提供所有的CRUD操作:增删改查。和往常一样,我将使用Mysql作为我的数据库。这个应用程序将把足球俱乐部相关的实体来作为示例,所以这个教程将会涉及运动领域。

准备

我需要在数据库中创建一个表,下面就是创建它的代码:

 CREATE TABLE `teams` ( `id` int(6) NOT NULL AUTO_INCREMENT, `name` varchar(40) NOT NULL, `rating` int(6) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8; 

这个表将在应用程序中用下面的类来表示:

 @Entity @Table(name="teams") public class Team {
@Id

 @GeneratedValue

 private Integer id;
private String name;
private Integer rating;
public Integer getId() {
return id;

 }

 public void setId(Integer id) {
this.id = id;

 }

 public String getName() {
return name;

 }

 public void setName(String name) {
this.name = name;

 }

 public Integer getRating() {
return rating;

 }

 public void setRating(Integer rating) {
this.rating = rating;

 }
} 

然后我需要在IDE(我使用Eclipse)里面创建一个Maven项目。我将略过创建的详细过程,你可以查看它在我的关于Maven项目的创建的文章里,这是pom.xml文件的链接。首先最重要的一点就是WebAppConfig.java 文件,所以我开始吧:

 @Configuration @ComponentScan("com.sprhib") @EnableWebMvc @EnableTransactionManagement @PropertySource("classpath:application.properties") public class WebAppConfig {
private static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";

 private static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";

 private static final String PROPERTY_NAME_DATABASE_URL = "db.url";

 private static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";

 private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";

 private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN = "entitymanager.packages.to.scan";
@Resource

 private Environment env;
@Bean

 public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
dataSource.setUrl(env.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
dataSource.setUsername(env.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
dataSource.setPassword(env.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));
return dataSource;

 }
@Bean

 public LocalSessionFactoryBean sessionFactory() {
LocalSessionFactoryBean sessionFactoryBean = new LocalSessionFactoryBean();
sessionFactoryBean.setDataSource(dataSource());
sessionFactoryBean.setPackagesToScan(env.getRequiredProperty( PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN));
sessionFactoryBean.setHibernateProperties(hibProperties());
return sessionFactoryBean;

 }
private Properties hibProperties() {
Properties properties = new Properties();
properties.put(PROPERTY_NAME_HIBERNATE_DIALECT, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
properties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));
return properties;
 }
@Bean

 public HibernateTransactionManager transactionManager() {
HibernateTransactionManager transactionManager = new HibernateTransactionManager();
transactionManager.setSessionFactory(sessionFactory().getObject());
return transactionManager;

 }
@Bean

 public UrlBasedViewResolver setupViewResolver() {
UrlBasedViewResolver resolver = new UrlBasedViewResolver();
resolver.setPrefix("/WEB-INF/pages/");
resolver.setSuffix(".jsp");
resolver.setViewClass(JstlView.class);
return resolver;

 }
} 

在这个文件开头,你看见了注解@EnableTransactionManagement,它可以使Spring的注解驱动事务管理器生效工作。注解@PropertySource(“classpath:application.properties”)定位属性文件所在的资源文件夹。注意着三个beans:transactionManager, sessionFactory, dataSource,这些beans提供了事务管理。更多信息可以阅读我的关于Hibernate功能的文章。

 #DB properties: db.driver=com.mysql.jdbc.Driver db.url=jdbc:mysql://localhost:3306/hibnatedb db.username=hibuser db.password=root
#Hibernate Configuration: hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect hibernate.show_sql=true entitymanager.packages.to.scan=com.sprhib.model 

以上是我和项目有关的所有准备,接下来我将向你展示DAO层和Service层。

DAO层和Service层

下面是DAOs和Services接口和实现:

 public interface TeamDAO {
public void addTeam(Team team);

 public void updateTeam(Team team);

 public Team getTeam(int id);

 public void deleteTeam(int id);

 public List

getTeams();
}
@Repository public class TeamDAOImpl implements TeamDAO {
@Autowired

 private SessionFactory sessionFactory;
private Session getCurrentSession() {
return sessionFactory.getCurrentSession();

 }
public void addTeam(Team team) {
getCurrentSession().save(team);

 }
public void updateTeam(Team team) {
Team teamToUpdate = getTeam(team.getId());
teamToUpdate.setName(team.getName());
teamToUpdate.setRating(team.getRating());
getCurrentSession().update(teamToUpdate);
}
public Team getTeam(int id) {
Team team = (Team) getCurrentSession().get(Team.class, id);
return team;

 }
public void deleteTeam(int id) {
Team team = getTeam(id);
if (team != null)

 getCurrentSession().delete(team);

 }
@SuppressWarnings("unchecked")

 public List

getTeams() {
return getCurrentSession().createQuery("from Team").list();

 }
} 

注解 @Repository 表明被注解的类是一个DAO

 public interface TeamService {
public void addTeam(Team team);

 public void updateTeam(Team team);

 public Team getTeam(int id);

 public void deleteTeam(int id);

 public List

getTeams();
}
@Service @Transactional public class TeamServiceImpl implements TeamService {
@Autowired

 private TeamDAO teamDAO;
public void addTeam(Team team) {
teamDAO.addTeam(team);
 }
public void updateTeam(Team team) {
teamDAO.updateTeam(team);

 }
public Team getTeam(int id) {
return teamDAO.getTeam(id);

 }
public void deleteTeam(int id) {
teamDAO.deleteTeam(id);

 }
public List

getTeams() {
return teamDAO.getTeams();

 }
} 

注解@Service表明备注解的类是一个“Service”。注解@Transactional在一个方法或者是类上声明一个事务。

控制器和JSPs

现在我就要涵盖所有的 CRUD操作,这一章会有点长。我将从最基础的控制器开始,它负责主页:

 @Controller public class LinkController {
@RequestMapping(value="/")

 public ModelAndView mainPage() {
return new ModelAndView("home");

 }
@RequestMapping(value="/index")

 public ModelAndView indexPage() {
return new ModelAndView("home");

 }
} 

它挺简单的,这是JSP文件:

 ... <h1>Home page</h1> <p> ${message}<br> <a href="${pageContext.request.contextPath}/team/add.html">Add new team</a><br> <a href="${pageContext.request.contextPath}/team/list.html">Team list</a><br> </p> ... 

下面是这里是核心控制器,主要应用程序的控制器:

 @Controller public class TeamController {
@Autowired

 private TeamService teamService;
@RequestMapping(value="/team/add")

 public ModelAndView addTeamPage() {
ModelAndView modelAndView = new ModelAndView("add-team-form");
modelAndView.addObject("team", new Team());
return modelAndView;

 }
@RequestMapping(value="/team/add/process")

 public ModelAndView addingTeam(@ModelAttribute Team team) {
ModelAndView modelAndView = new ModelAndView("home");
teamService.addTeam(team);
String message = "Team was successfully added.";
modelAndView.addObject("message", message);
return modelAndView;

 }
@RequestMapping(value="/team/list")

 public ModelAndView listOfTeams() {
ModelAndView modelAndView = new ModelAndView("list-of-teams");
List

teams = teamService.getTeams();
modelAndView.addObject("teams", teams);
return modelAndView;

 }
@RequestMapping(value="/team/edit/{id}", method=RequestMethod.GET)

 public ModelAndView editTeamPage(@PathVariable Integer id) {
ModelAndView modelAndView = new ModelAndView("edit-team-form");
Team team = teamService.getTeam(id);
modelAndView.addObject("team",team);
return modelAndView;

 }
@RequestMapping(value="/team/edit/{id}", method=RequestMethod.POST)

 public ModelAndView edditingTeam(@ModelAttribute Team team, @PathVariable Integer id) {
ModelAndView modelAndView = new ModelAndView("home");
teamService.updateTeam(team);
String message = "Team was successfully edited.";
modelAndView.addObject("message", message);
return modelAndView;

 }
@RequestMapping(value="/team/delete/{id}", method=RequestMethod.GET)

 public ModelAndView deleteTeam(@PathVariable Integer id) {
ModelAndView modelAndView = new ModelAndView("home");
teamService.deleteTeam(id);
String message = "Team was successfully deleted.";
modelAndView.addObject("message", message);
return modelAndView;

 }
} 

基本上所有的方法和请求映射都是很清晰的。请注意editTeamPage() 和edditingTeam() 方法的@RequestMapping,对于不同的method属性包含不同的值。
现在我们来看看JSP页面:

“Add new team” 页面

 ... <h1>Add team page</h1> <p>Here you can add a new team.</p> <form:form method="POST" commandname="team" action="${pageContext.request.contextPath}/team/add/process.html"> <table> <tbody>

 <tr>
<td>Name:</td>
<td><form:input path="name"></form:input></td>

 </tr>

 <tr>
<td>Rating:</td>
<td><form:input path="rating"></form:input></td>

 </tr>

 <tr>
<td><input value="Add" type="submit"></td>
<td></td>

 </tr> </tbody> </table> </form:form>
<p><a href="${pageContext.request.contextPath}/index.html">Home page</a></p> ... 

“List of teams” 页面:

 ... <h1>List of teams</h1> <p>Here you can see the list of the teams, edit them, remove or update.</p> <c:foreach var="team" items="${teams}"> </c:foreach><table border="1px" cellpadding="0" cellspacing="0"> <thead> <tr> <th width="10%">id</th><th width="15%">name</th><th width="10%">rating</th><th width="10%">actions</th> </tr> </thead> <tbody> <tr>

 <td>${team.id}</td>

 <td>${team.name}</td>

 <td>${team.rating}</td>

 <td>

 <a href="${pageContext.request.contextPath}/team/edit/${team.id}.html">Edit</a><br>

 <a href="${pageContext.request.contextPath}/team/delete/${team.id}.html">Delete</a><br>

 </td> </tr>
</tbody> </table>
<p><a href="${pageContext.request.contextPath}/index.html">Home page</a></p> ... 

“Edit team” 页面:

 ... <h1>Edit team page</h1> <p>Here you can edit the existing team.</p> <p>${message}</p> <form:form method="POST" commandname="team" action="${pageContext.request.contextPath}/team/edit/${team.id}.html"> <table> <tbody>

 <tr>
<td>Name:</td>
<td><form:input path="name"></form:input></td>

 </tr>

 <tr>
<td>Rating:</td>
<td><form:input path="rating"></form:input></td>

 </tr>

 <tr>
<td><input value="Edit" type="submit"></td>
<td></td>

 </tr> </tbody> </table> </form:form>
<p><a href="${pageContext.request.contextPath}/index.html">Home page</a></p> ... 

“List of teams” 页面的效果:

总结

几个技术的整合通常不是一件简单的事情,所有如果要想成功就需要有耐心。在这篇文章中没有囊括所有的资源,你可以访问GitHub去查看哪些你感兴趣的类。

原文链接: javacodegeeks 翻译: ImportNew.com - wudy
译文链接: http://www.importnew.com/11121.html
[ 转载请保留原文出处、译者和译文链接。]

关于作者: wudy

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