昨天做了一个使用JSF的一个helloworld的小练习，它并没有和后端数据交互。
今天我来加上JPA来持久化数据对象，前台依然使用JSF来展现，做一个完整的Web应用。
这个应用的功能是用户输入用户名和密码后，通过JPA来查询后台数据库进行校验，如果成功则进入欢迎页面。
开发环境：
Eclipse Juno，
JSF2.1,
JPA框架：EclipseLink 2.4，
数据库：MySql 5.5
Web应用服务器: Tomcat 7.0
1.首先安装MySQL数据库，数据库信息：
登录数据库，并创建一个table：
mysql> create table users (id integer primary key, name varchar(120), login varchar(75) not null, password varchar(75) not null);
然后输入几条测试用户信息：
2.创建一个叫做webusers的Dynamic Web项目，并添加JPA Facet。
3.编辑persistence.xml文件
Persistence Provider:
org.eclipse.persistence.jpa.PersistenceProvider
以及数据库相关信息，
完整的persistence.xml:
<?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> <persistence-unit name="webusers" transaction-type="RESOURCE_LOCAL"> <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> <class>logon.User</class> <properties> <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:8889/test" /> <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" /> <property name="javax.persistence.jdbc.user" value="root" /> <property name="javax.persistence.jdbc.password" value="root" /> </properties> </persistence-unit> </persistence>
4.创建Entity User
package logon;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "USERS")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
String Name = null;
String Login = null;
String Password = null;
public int get_Id() {
return id;
}
public void set_Id(int id) {
this.id = id;
}
public String getName() {
return Name;
}
public void setName(String Name) {
this.Name = Name;
}
public String getLogin() {
return Login;
}
public void setLogin(String Login) {
this.Login = Login;
}
public String getPassword() {
return Password;
}
public void setPassword(String Password) {
this.Password = Password;
}
}
5.为项目加上JSF的facet
6.打开faces-config.xml，在managedBean页面加入一个Session Bean: logonBean
7.创建SessionBean class
package logon;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;
public class LogonBean {
private static final String PERSISTENCE_UNIT_NAME = "webusers";
private static EntityManagerFactory factory;
private String userName;
private String password;
public LogonBean() {
}
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 validate() {
String flag = "failure";
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager em = factory.createEntityManager();
Query q = em
.createQuery("SELECT u FROM User u WHERE u.Login = :login AND u.Password = :pass");
q.setParameter("login", userName);
q.setParameter("pass", password);
try {
User user = (User) q.getSingleResult();
if (userName.equalsIgnoreCase(user.Login)
&& password.equals(user.Password)) {
flag = "success";
}
} catch (Exception e) {
return null;
}
return flag;
}
}
8.创建页面模板，BasicTemplate.xhtml, footer.xhtml, header.xhtml.
BasicTemplate.xhtml:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets">
<head>
<title><ui:insert name="title">Facelets Tutorial</ui:insert></title>
</head>
<body>
<div id="header">
<ui:insert name="header">
<ui:include src="/WEB-INF/templates/header.xhtml"/>
</ui:insert>
</div>
<div id="content">
<ui:insert name="content">
</ui:insert>
</div>
<div id="footer">
<ui:insert name="footer">
<ui:include src="/WEB-INF/templates/footer.xhtml"/>
</ui:insert>
</div>
</body>
</html><?xml version="1.0" encoding="ISO-8859-1" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <body> <div style="width:100%;font-size:36px;line-height:48px;background-color:navy;color:white">My Facelet Application</div> </body> </html>
<?xml version="1.0" encoding="ISO-8859-1" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /> <title>Insert title here</title> </head> <body> <div style="background-color:navy;width:100%;color:white"></div> </body> </html>
9.最后创建logon页面和welcome.xhtml页面。
logon.xhtml:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<ui:composition template="/WEB-INF/templates/BasicTemplate.xhtml">
<ui:define name="content">
<h:form>
<h:panelGrid columns="2">
<h:outputText value="Name"></h:outputText>
<h:inputText value="#{logonBean.userName}"></h:inputText>
<h:outputText value="Password"></h:outputText>
<h:inputSecret value="#{logonBean.password}"></h:inputSecret>
</h:panelGrid>
<h:commandButton value="Login" action="#{logonBean.validate}"></h:commandButton>
</h:form>
</ui:define>
</ui:composition>
</html><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<ui:composition template="/WEB-INF/templates/BasicTemplate.xhtml">
<ui:define name="content">
<h:outputLabel value="Welcome #{logonBean.userName}"></h:outputLabel>
</ui:define>
</ui:composition>
</html>10.打开face-config.xml，创建页面导航。
11.终于搞定了！在Tomcat服务器上测试运行一下，输入后台数据库users表里的用户信息来登录。
小结：
这个小例子在上一个练习的基础上修改加工完成的。
通过JPA来实现数据对象的操作，然后通过JSF的页面模板来展示数据，思路非常简单清晰。
Web编程学习二: 使用JPA结合JSF来创建Web应用,布布扣,bubuko.com
原文：http://blog.csdn.net/starshus/article/details/22575697
