尝试利用JSF作为Spring MVC的视图（初级篇）

  之前研究学习Spring MVC的时候总是用JSP作为视图，偶尔也尝试过Thymleaf，学习Java EE开发的时候又尝试过JSF，之前也翻译过一篇有关Spring Boot和JSF整合的文章——请参阅用Spring Boot开发JSF应用程序（翻译）。在此，对利用JSF作为视图进行Spring MVC开发进行详细的说明，从最开始的工程构建到实例的运行进行分享。这里只是把JSP简单替换成为JSF，如果比较熟悉的话，可以进一步看看尝试利用JSF作为Spring MVC的视图（探索篇）之表格的排序与选择
  首先介绍一下开发环境：

• JDK版本：1.8.0_181
• Maven版本：Apache Maven 3.6.0
• Spring Tool Suite版本：3.9.7.RELEASE
• JBoss Tools版本：4.9.0 Final
• Tomcat版本：9.0.14
• Spring FrameWork版本：5.1.3.RELEASE
• lombok版本：1.18.4
• MyFaces版本：2.3.2
• Prime Faces版本：6.2

  下面开始按照开发步骤进行说明，也作为自己的备忘。
  首先需要创建Maven工程并转换为Web工程。
  参考下面的步骤，创建一个简单的Maven工程。

  设置工程的信息，点击Finish。

  编辑pom.xml文件。

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0modelVersion>
	<groupId>org.study.basicgroupId>
	<artifactId>SpringJSFBasicartifactId>
	<version>0.0.1-SNAPSHOTversion>
	<packaging>warpackaging>
	<properties>
		<project.build.sourceEncoding>utf-8project.build.sourceEncoding>
		<maven.compiler.source>1.8maven.compiler.source>
		<maven.compiler.target>1.8maven.compiler.target>
	properties>
	<dependencies>
		<dependency>
			<groupId>org.springframeworkgroupId>
			<artifactId>spring-webmvcartifactId>
			<version>5.1.3.RELEASEversion>
		dependency>
		<dependency>
			<groupId>org.apache.tomcat.embedgroupId>
			<artifactId>tomcat-embed-jasperartifactId>
			<version>9.0.14version>
			<scope>providedscope>
		dependency>
		<dependency>
			<groupId>org.apache.myfaces.coregroupId>
			<artifactId>myfaces-apiartifactId>
			<version>2.3.2version>
		dependency>
		<dependency>
			<groupId>org.apache.myfaces.coregroupId>
			<artifactId>myfaces-implartifactId>
			<version>2.3.2version>
		dependency>
		<dependency>
			<groupId>org.primefacesgroupId>
			<artifactId>primefacesartifactId>
			<version>6.2version>
		dependency>
		<dependency>
			<groupId>org.projectlombokgroupId>
			<artifactId>lombokartifactId>
			<version>1.18.4version>
			<optional>trueoptional>
		dependency>
	dependencies>
project>

  刷新Maven工程，用Alt + F5，或者右键菜单。

  工程会转换成Web工程，但是会提示缺少web.xml文件。

  利用右键菜单生成web.xml文件，如下图：

  编辑web.xml文件的内容如下：
  注意： 这里使用了默认设置，并没有指定具体的文件路径。

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://xmlns.jcp.org/xml/ns/javaee"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
	version="4.0">
	<display-name>SpringJSFBasicdisplay-name>
	<context-param>
		<param-name>javax.faces.PROJECT_STAGEparam-name>
		<param-value>Developmentparam-value>
	context-param>
	<servlet>
		<servlet-name>mvcservlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
		<load-on-startup>1load-on-startup>
	servlet>
	<servlet-mapping>
		<servlet-name>mvcservlet-name>
		<url-pattern>/url-pattern>
	servlet-mapping>
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
	listener>
	<listener>
		<listener-class>org.springframework.web.context.request.RequestContextListenerlistener-class>
	listener>
	<welcome-file-list>
		<welcome-file>index.xhtmlwelcome-file>
	welcome-file-list>
web-app>

  在/WEB-INF路径下添加applicationContext.xml和mvc-servlet.xml，内容如下：

1. applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
	<context:annotation-config />
	<context:component-scan
		base-package="org.study.basic.service" />
beans>

2. mvc-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">
	<mvc:annotation-driven />
	<context:component-scan
		base-package="org.study.basic.mvc" />
	<bean id="viewResolver"
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/views/" />
		<property name="suffix" value=".xhtml" />
	bean>
beans>

  接着是添加如下的代码文件，比较简单，不需要详细说明。关键是利用lombok的方法，可以参照相关的文章。

1. Student.java

package org.study.basic.repository.data;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Student {
	private long id;
	private String name;
	private int age;
	private String description;
}

2. StudentService.java

package org.study.basic.service;

import java.util.List;

import org.study.basic.repository.data.Student;

public interface StudentService {

	Student findStudentById(long id);

	List<Student> findAllStudents();
}

3. StudentServiceImpl.java

package org.study.basic.service.impl;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.stereotype.Service;
import org.study.basic.repository.data.Student;
import org.study.basic.service.StudentService;

@Service
public class StudentServiceImpl implements StudentService {

	private Map<Long, Student> mapStudent;

	public StudentServiceImpl() {
		this.initForTest();
	}

	@Override
	public Student findStudentById(long id) {
		return this.mapStudent.get(id);
	}

	@Override
	public List<Student> findAllStudents() {
		return new ArrayList<Student>(this.mapStudent.values());
	}

	private void initForTest() {
		this.mapStudent = new HashMap<Long, Student>();
		this.mapStudent.put(1L, new Student(1, "学生一", 25, "擅长前端开发"));
		this.mapStudent.put(2L, new Student(2, "学生二", 26, "擅长后端开发"));
		this.mapStudent.put(3L, new Student(3, "学生三", 24, "擅长算法设计"));
	}
}

4. StudentController .java

package org.study.basic.mvc.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.study.basic.repository.data.Student;
import org.study.basic.service.StudentService;

@Controller
@RequestMapping("/student")
public class StudentController {

	@Autowired
	private StudentService studentService;

	@RequestMapping(value = "/info", method = RequestMethod.GET)
	public String showInfo(Model model) {
		Student student = this.studentService.findStudentById(2);
		model.addAttribute("student", student);

		List<Student> students = this.studentService.findAllStudents();
		model.addAttribute("students", students);
		return "showInfo";
	}
}

  最后在/WEB-INF/views路径下添加一个简单的showInfo.xhtml文件，内容如下：

<html xmlns="http://www.w3.org/1999/xhtml"
	xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:f="http://java.sun.com/jsf/core"
	xmlns:h="http://java.sun.com/jsf/html"
	xmlns:p="http://primefaces.org/ui">

<h:head>h:head>
<h:body>
	<h2>最佳学生：h2>
	<h:outputText value="${student.name}" />
	<h2>全体学生：h2>
	<p:dataTable value="${students}" var="student" selectionMode="single"
		rowKey="${student.id}">
		<p:column headerText="姓名">
			<h:outputText value="${student.name}" />
		p:column>
		<p:column headerText="年龄">
			<h:outputText value="${student.age}" />
		p:column>
		<p:column headerText="特长">
			<h:outputText value="${student.description}" />
		p:column>
	p:dataTable>
h:body>
html>

  最后的工程结构如下图：

  部署工程并运行。


  访问http://127.0.0.1:8080/SpringJSFBasic/student/info，效果如下：

  有关JSF的高级话题请关注后续文章。