Primefaces，带有JPA的Spring 4(Hibernate 4/EclipseLink)示例教程
时间：2020-02-23 14:41:39 来源:igfitidea点击:
Java Persistence API是一个标准规范。
它提供了由不同实施者框架实施的持久性模型。
Primefaces Spring Hibernate EclipseLink
" Hibernate"和" EclipseLink"是两个最流行的实现，用于将给定的业务模型持久化为某种持久性存储，例如关系数据库。
这样，本教程将为您提供完整的示例，其中包含开发使用以下内容的分层应用程序所需的所有必需配置步骤：
Primefaces组件可开发引人注目的用户界面，旨在处理用户的互动并验证用户的输入。
Hibernate/EclipseLink实现可在JPA框架下开发对象/关系映射。
Spring框架是一种胶粘剂，可以将所有东西都粘在一起。
在使用Hibernate ORM保留给定的域类之前，我们已经进行了讨论。
但是今天，我们将仅使用基于JPA的配置。
JPA规范以不同的方式进行引导。
在休眠状态下，我们使用" hibernate.cfg.xml"文件引导了应用程序，但JPA未指定该文件。
JPA提供了另一种配置方式，它使用位于您的"类路径"内" META-INF"文件夹下的" persistence.xml"文件。
让我们看看如何同时使用"休眠"和" EclipseLink"来实现单个注册表单。
Primefaces Spring JPA Hibernate EclipseLink示例所需工具
在继续进行之前，您必须准备以下环境：
JDK 1.6以上版本。
Eclipse开普勒4.3。
休眠4.3.6。
最终版。Spring 4.0.3发布。
EclipseLink 2.5.0-RC1
Maven构建工具
MySQL5.x。
Primefaces Spring JPA Hibernate EclipseLink示例项目结构
Primefaces Spring JPA Hibernate EclipseLink示例数据库表
我们的MySQL数据库中有Employee表，您可以使用以下脚本来创建它。
CREATE TABLE `employee` ( `EMP_ID` int(11) NOT NULL AUTO_INCREMENT, `EMP_NAME` varchar(45) DEFAULT NULL, `EMP_HIRE_DATE` datetime DEFAULT NULL, `EMP_SALARY` decimal(11,4) DEFAULT NULL, PRIMARY KEY (`EMP_ID`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
- 员工表包含一个具有自动增量值的主键。
Primefaces Spring JPA Hibernate EclipseLink示例域类
我们还有一个域类，该域类将持久存储到我们的数据库Employee表中。
Employee.java
package com.theitroad.hibernate.jpa.data;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
@Entity
public class Employee {
@Id
@Column(name="EMP_ID")
private long employeeId;
@Column(name="EMP_NAME")
private String employeeName;
@Column(name="EMP_HIRE_DATE")
@Temporal(TemporalType.TIMESTAMP)
private Date employeeHireDate;
@Column(name="EMP_SALARY")
private double employeeSalary;
public long getEmployeeId() {
return employeeId;
}
public void setEmployeeId(long employeeId) {
this.employeeId = employeeId;
}
public String getEmployeeName() {
return employeeName;
}
public void setEmployeeName(String employeeName) {
this.employeeName = employeeName;
}
public Date getEmployeeHireDate() {
return employeeHireDate;
}
public void setEmployeeHireDate(Date employeeHireDate) {
this.employeeHireDate = employeeHireDate;
}
public double getEmployeeSalary() {
return employeeSalary;
}
public void setEmployeeSalary(double employeeSalary) {
this.employeeSalary = employeeSalary;
}
}
JPA提供@Entity，用于将Employee指示为持久域类。
为了将这个持久实体与其员工表进行映射，将发生默认映射。
如果您提供的表名或者类名不相同，则必须使用@Table。@Id注释用于指示给定Employee实例的身份。
由于属性名称和列名称之间存在差异，因此必须提供@column。@Column name批注采用映射列名称的参数。
Primefaces Spring JPA Hibernate EclipseLink示例持久性单元
如前所述，JPA提供了一种引导JPA框架的替代方法，它是一个" persistence.xml"文件。
该文件的最小数量应类似于：
persistence.xml
<persistence xmlns="https://java.sun.com/xml/ns/persistence" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://java.sun.com/xml/ns/persistence https://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0"> <!-- Will be referenced in Spring Context File --> <persistence-unit name="jpa-persistence" transaction-type="RESOURCE_LOCAL"> <class>com.theitroad.hibernate.jpa.data.Employee</class> <properties> <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/theitroad" <property name="javax.persistence.jdbc.user" value="hyman" <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" <property name="javax.persistence.jdbc.password" value="hyman123" </properties> </persistence-unit> </persistence>
持久性单元应定义：
持久性单元名称。
该名称将由Spring上下文引用。事务类型– JPA实现可以选择自行管理资源(RESOURCE_LOCAL)还是由应用服务器的JTA实现进行管理。
有关数据库连接的信息。
Primefaces Spring JPA Hibernate EclipseLink示例Maven依赖项
所有必需的库都在Maven本身读取的pom.xml文件中列出。
pom.xml
<project xmlns="https://maven.apache.org/POM/4.0.0" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.theitroad</groupId> <artifactId>Primefaces-Hibernate-JPA-Spring-Integration-Sample</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>Primefaces-Hibernate-JPA-Spring-Integration-Sample Maven Webapp</name> <url>https://maven.apache.org</url> <repositories> <repository> <id>prime-repo</id> <name>PrimeFaces Maven Repository</name> <url>https://repository.primefaces.org</url> <layout>default</layout> </repository> </repositories> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <!-- Servlet --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <!-- Faces Implementation --> <dependency> <groupId>com.sun.faces</groupId> <artifactId>jsf-impl</artifactId> <version>2.2.4</version> </dependency> <!-- Faces Library --> <dependency> <groupId>com.sun.faces</groupId> <artifactId>jsf-api</artifactId> <version>2.2.4</version> </dependency> <!-- Primefaces Version 5 --> <dependency> <groupId>org.primefaces</groupId> <artifactId>primefaces</artifactId> <version>5.0</version> </dependency> <!-- JSP Library --> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>javax.servlet.jsp-api</artifactId> <version>2.3.1</version> </dependency> <!-- JSTL Library --> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.1.2</version> </dependency> <!-- Hibernate 4.3.6 core library library --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>4.3.6.Final</version> </dependency> <!-- Hibernate 4.3.6 JPA support --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-entitymanager</artifactId> <version>4.3.6.Final</version> </dependency> <!-- MySQL driver connector library --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.31</version> </dependency> <!-- Spring ORM --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>4.0.3.RELEASE</version> </dependency> <!-- Spring Web --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.0.3.RELEASE</version> </dependency> <!-- Dependencies for Eclipse JPA Persistence API --> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>eclipselink</artifactId> <version>2.5.0-RC1</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.6</source> <target>1.6</target> </configuration> </plugin> </plugins> </build> </project>
Hibernate/JPA Spring配置
持续使用JPA需要一个EntityManager实例。
可以通过配置适当的Spring上下文来获取此实例。
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="https://www.springframework.org/schema/beans" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xmlns:tx="https://www.springframework.org/schema/tx" xmlns:context="https://www.springframework.org/schema/context" xmlns:aop="https://www.springframework.org/schema/aop" xmlns:util="https://www.springframework.org/schema/util" xsi:schemaLocation="https://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd https://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd https://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context-3.2.xsd https://www.springframework.org/schema/tx https://www.springframework.org/schema/tx/spring-tx-3.2.xsd"> <!-- Enable Spring Annotation Configuration --> <context:annotation-config <!-- Scan for all of Spring components such as Spring Service --> <context:component-scan base-package="com.theitroad.spring.service"></context:component-scan> <!-- Necessary to get the entity manager injected into the factory bean --> <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" <!-- Define Hibernate JPA Vendor Adapter --> <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" </bean> <!-- Entity Manager Factory --> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> <property name="persistenceUnitName" value="hibernate.jpa"></property> <property name="jpaVendorAdapter" ref="jpaVendorAdapter" </bean> <!-- Transaction Manager --> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" </bean> <!-- Detect @Transactional --> <tx:annotation-driven transaction-manager="transactionManager" </beans>
JPA需要一个entityManagerFactory对象，它是org.springframework.orm.jpa.LocalEntityFactoryBean的实例。
必须为该实例提供名称persistenceUnit和JPAVendorAdapter。为了正确使用
@ Trasnactional注释，应该定义TransactionManager。Spring上下文配置的默认名称和位置是
applicationContext.xml且在WEB-INF文件夹的下面。
EclipseLink/JPA Spring配置
EclipseLink将使用相同的配置，只需做一点改动即可提供EclipseLink的JPA供应商。
只需将jpaVendorAdapter bean更改为下面的内容，使用的JPA实现将是EclipseLink。
applicationContext.xml
<!-- Define EclipseLink JPA Vendor Adapter --> <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter"> <property name="databasePlatform" value="org.eclipse.persistence.platform.database.MySQLPlatform" <property name="generateDdl" value="false" <property name="showSql" value="true" </bean>
Primefaces部署描述符
正确配置Spring需要将Spring侦听器添加到Primefaces的部署描述符" web.xml"应用程序中。
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xmlns="https://java.sun.com/xml/ns/javaee" xmlns:web="https://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="https://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5" metadata-complete="true"> <servlet> <servlet-name>Faces Servlet</servlet-name> <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>/faces/*</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>*.xhtml</url-pattern> </servlet-mapping> <context-param> <description>State saving method: 'client' or 'server' (=default). See JSF Specification 2.5.2</description> <param-name>javax.faces.STATE_SAVING_METHOD</param-name> <param-value>client</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <listener> <listener-class>com.sun.faces.config.ConfigureListener</listener-class> </listener> </web-app>
Spring员工服务
Spring服务是表示层和持久层之间的交互点。
如果您熟悉DAO，可以考虑采用类似的方法。
EmployeeService.java
package com.theitroad.spring.service;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import com.theitroad.hibernate.jpa.data.Employee;
@Component
public class EmployeeService {
@PersistenceContext
private EntityManager em;
public EntityManager getEm() {
return em;
}
public void setEm(EntityManager em) {
this.em = em;
}
@Transactional
public void register(Employee emp) {
//Save employee
this.em.persist(emp);
}
}
- EntityManager是使用@PersistenceContext注解注入的。
即使您已经定义了EntityManagerFactory的实例，但是JPA实现也非常聪明，可以为您注入EntityManager的实例。
EntityManager与Hibernate中的Session类似。
如果您在上下文事务和活动事务中都调用了它的任何CRUD操作，则该操作将在持久性存储中保留下来。
请注意em.persist()并在注册方法上使用@Transactional批注。
Primefaces托管Bean – RegisterEmployee
RegisterEmployee是一个面孔管理的Bean，用于处理用户交互和验证用户输入。
ResgiterEmployee.java
package com.theitroad.prime.faces.beans;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
import com.theitroad.jpa.data.Employee;
import com.theitroad.spring.service.EmployeeService;
@ManagedBean
@SessionScoped
public class RegisterEmployee {
@ManagedProperty("#{employeeService}")
private EmployeeService employeeService;
private Employee employee = new Employee();
public EmployeeService getEmployeeService() {
return employeeService;
}
public void setEmployeeService(EmployeeService employeeService) {
this.employeeService = employeeService;
}
public Employee getEmployee() {
return employee;
}
public void setEmployee(Employee employee) {
this.employee = employee;
}
public String register() {
//Calling Business Service
employeeService.register(employee);
//Add message
FacesContext.getCurrentInstance().addMessage(null,
new FacesMessage("The Employee "+this.employee.getEmployeeName()+" Is Registered Successfully"));
return "";
}
}
Spring服务EmployeeService是使用Spring el-reslover注入的，并通过faces-config.xml进行了声明。
Register方法会将调用委托到注入的EmployeeService实例中。
这样，EmployeeService将处理实际注册。
Primefaces员工注册页面
index.xhtml
<html xmlns="https://www.w3.org/1999/xhtml"
xmlns:ui="https://java.sun.com/jsf/facelets"
xmlns:h="https://java.sun.com/jsf/html"
xmlns:f="https://java.sun.com/jsf/core"
xmlns:p="https://primefaces.org/ui">
<h:head>
<script name="jquery/jquery.js" library="primefaces"></script>
<title>Register Employee</title>
</h:head>
<h:form>
<p:growl id="messages"></p:growl>
<p:panelGrid columns="2">
<p:outputLabel value="Enter Employee Name:"></p:outputLabel>
<p:inputText value="#{registerEmployee.employee.employeeName}"></p:inputText>
<p:outputLabel value="Enter Employee Hire Date:"></p:outputLabel>
<p:calendar value="#{registerEmployee.employee.employeeHireDate}"></p:calendar>
<p:outputLabel value="Enter Employee Salary:"></p:outputLabel>
<p:inputText value="#{registerEmployee.employee.employeeSalary}"></p:inputText>
</p:panelGrid>
<p:commandButton value="Register" action="#{registerEmployee.register}" update="messages"></p:commandButton>
</h:form>
</html>
