Spring 框架入门教程-55. Spring Primefaces JPA-55编程教程网

Java持久性API是一个标准规范。它提供了一个持久化模型，该模型由不同的实现框架实现。

1Spring Primefaces春眠Eclipse

Spring Primefaces春眠Eclipse

Hibernate & EclipseLink are two most popular implementations used for persisting given business model against some sort of persistence store like relational database. As such, this tutorial will provide you a full-fledged example containing all required configuration steps to developer a layered application that uses:

Primefaces组件开发一个引人注目的用户界面，旨在处理用户和验证用户的输入。
Hibernate/EclipseLink实现在JPA伞下开发对象/关系映射。
springframework作为一种粘合剂，将所有的东西连接在一起。

在使用Hibernate ORM持久化给定的域类之前，我们已经讨论过。但今天我们将只使用基于JPA的配置。

JPA规范以不同的方式进行引导。在hibernate中，我们使用hibernate.cfg.xml file, but JPA doesn’t specify that file.

JPA提供了另一种配置方法，它使用persistence.xml file that is located within your classpath and under META-INF folder.

让我们看看如何同时使用这两种方法Hibernate and EclipseLink for implementing a single registration form.

Primefaces Spring JPA Hibernate EclipseLink示例所需工具

在继续前进之前，您必须准备好环境，这些环境应包含：

JDK 1.6+。
Eclipse开普勒4.3。
Hibernate最终版。
Spring4.0.3.释放。
EclipseLink 2.5.0-RC1
Maven构建工具
MySQL5.x。

Primefaces Spring JPA Hibernate EclipseLink项目结构示例

Primefaces Spring JPA Hibernate EclipseLink示例数据库表

我们的MySQL数据库中有Employee表，您可以使用下面的脚本创建它。


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;

Employee表包含一个具有自动递增值的主键。

PrimeLine域Hibernate Eclipse类示例

我们还有一个域类，它将持久化到数据库Employee表中。

Employee.java


package com.journaldev.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提供了@Entity，它将用于将Employee表示为一个持久的域类。为了将这个持久性实体与其Employee表映射，将发生默认映射。如果您提供的表名或类名不相同，则必须使用@Table。
@用于指示给定雇员实例的标识的Id注解。由于属性名和列名之间存在差异，必须提供@column。
@列名批注接受映射列名的参数。

Primefaces Spring JPA Hibernate EclipseLink示例持久性单元

正如我们前面提到的，JPA为引导JPA框架提供了另一种方法，它是persistence.xml file. The minimum amount of this file should look like:

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.journaldev.hibernate.jpa.data.Employee</class>
		<properties>
			<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/journaldev" />
			<property name="javax.persistence.jdbc.user" value="pankaj" />
			<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
			<property name="javax.persistence.jdbc.password" value="pankaj123" />
		</properties>
	</persistence-unit>
</persistence>

持久性单元应定义：

持久性单元名称。该名称将被Spring上下文引用。
事务类型和JPA实现可以选择自己管理资源(RESOURCE_LOCAL) or having them managed by the application server’s JTA implementation.
有关数据库连接的信息。

Primefaces Spring JPA Hibernate EclipseLink示例Maven依赖项

所有必需的库都列在中pom.xml file that’s read by Maven itself.

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.journaldev</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

持久使用JPA需要EntityManager实例。这个实例可以通过配置适当的Spring上下文获得。

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.journaldev.spring.service"></context:component-scan>

	<!-- Necessary to get the entity manager injected into the factory bean -->
	<bean />	

	<!-- Define Hibernate JPA Vendor Adapter -->
	<bean id="jpaVendorAdapter"
	>
		<property name="databasePlatform"
			value="org.hibernate.dialect.MySQLDialect" />
	</bean>	

	<!-- Entity Manager Factory -->
	<bean id="entityManagerFactory"
	>
		<property name="persistenceUnitName" value="hibernate.jpa"></property>
		<property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
	</bean>

	<!-- Transaction Manager -->
	<bean id="transactionManager">
		<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. This instance must be provided with the name of persistenceUnit and a JPAVendorAdapter.
使用@Trasnactional annotation properly, TransactionManager should be defined.
Spring上下文配置的默认名称和位置是applicationContext.xml and beneath of WEB-INF folder.

EclipseLink/JPASpring配置

与EclipseLink提供的配置相同。只要换一下JPaventorAdapter下面的bean和JPA实现将使用EclipseLink。

applicationContext.xml


	<!-- Define EclipseLink JPA Vendor Adapter -->
	<bean id="jpaVendorAdapter"
	>
		<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&8217；部署描述符中web.xml application.

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就业服务

Spring服务是表示层和持久层之间的交互点。如果您熟悉DAO，您可以将其视为类似的东西。

EmployeeService.java


package com.journaldev.spring.service;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import com.journaldev.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);
	}
}

使用@PersistenceContext annotation. Even you’ve defined an instance of EntityManagerFactory, but a JPA implementation will be very smart to inject you an instance of EntityManager. EntityManager would be something similar for Session in Hibernate. In case you’ve invoked any of its CRUD operation within both of context and active transaction, your operation would be persisted against your persistence store. Note that em.persist() and using of @Transactional annotation upon register method.

Primefaces托管Bean和注册员工

registereemployee是一个faces管理的bean，用于处理用户交互和用户输入的验证。

ResgiterEmployee.java


package com.journaldev.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.journaldev.jpa.data.Employee;
import com.journaldev.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 "";
	}
}

springserviceeemployeeservice是使用springel reslover注入的，它是用你的脸声明的-配置.xml.
Register方法将把调用委托给注入的EmployeeService实例。因此，EmployeeService将处理真实的注册。

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>