作为 Spring Boot 运行工作的 JSF 应用程序会抛出 javax.el.PropertyNotFoundException: Target Unreachable, identifier resolve to null答案

【问题标题】：Running working JSF application as Spring Boot throws javax.el.PropertyNotFoundException: Target Unreachable, identifier resolved to null作为 Spring Boot 运行工作的 JSF 应用程序会抛出 javax.el.PropertyNotFoundException: Target Unreachable, identifier resolve to null
【发布时间】：2018-09-21 22:04:45
【问题描述】：

我正在尝试使用 primefaces 创建演示 SpringBoot 应用程序。我从以下 url 获取源代码并将其转换为 SpringBoot App：-

jsf-primefaces-hello-world-example-apache-tomcat

当我使用（将 tomcat 插件添加到 pom 之后）运行代码时，代码运行良好（甚至是 ManagedBean）：-

mvn tomcat7:运行

但是，当我将它作为 SpringBoot 应用程序运行时，HelloWorld bean 似乎没有注册为 ManagedBean。我读了BalusC 的一篇很有用的post，我还是想不通。应用程序 UI 工作正常。我很确定我错过了一些非常愚蠢的东西，但我似乎找不到它。我读了很多帖子（大多标记为重复），但这也无济于事。

任何帮助将不胜感激..

代码与原始帖子几乎相同，这里和那里有一些变化：-

DemoClass.java

package com.codenotfound.primefaces;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import javax.servlet.ServletContainerInitializer;
import javax.servlet.annotation.HandlesTypes;

import org.apache.catalina.Context;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.embedded.tomcat.TomcatContextCustomizer;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
//import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
//import org.springframework.boot.context.embedded.tomcat.TomcatContextCustomizer;
//import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import com.sun.faces.config.FacesInitializer;

@Configuration
@ComponentScan
@EnableAutoConfiguration
@SpringBootApplication
public class DemoClass {
    public static void main(String[] args) throws Exception {
        SpringApplication.run(DemoClass.class, args);
    }

    @Bean
    public TomcatServletWebServerFactory embeddedServletContainerFactory() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();

        tomcat.addContextCustomizers(new TomcatContextCustomizer() {
            @Override
            public void customize(Context context) {
                context.addServletContainerInitializer(new FacesInitializer(),
                        getServletContainerInitializerHandlesTypes(FacesInitializer.class));
                context.addWelcomeFile("index.jsf");
                context.addMimeMapping("eot", "application/vnd.ms-fontobject");
                context.addMimeMapping("ttf", "application/x-font-ttf");
                context.addMimeMapping("woff", "application/x-font-woff");
            }
        });

        return tomcat;
    }

    @SuppressWarnings("rawtypes")
    private Set<Class<?>> getServletContainerInitializerHandlesTypes(Class<? extends ServletContainerInitializer> sciClass) {
        HandlesTypes annotation = sciClass.getAnnotation(HandlesTypes.class);
        if (annotation == null) {
            return Collections.emptySet();
        }

        Class[] classesArray = annotation.value();
        Set<Class<?>> classesSet = new HashSet<Class<?>>(classesArray.length);
        for (Class clazz: classesArray) {
            classesSet.add(clazz);
        }

        return classesSet;
    }

}

HelloWorld.java

package com.codenotfound.primefaces.bean;

import javax.faces.bean.ManagedBean;

@ManagedBean
public class HelloWorld {

  private String firstName = "John";
  private String lastName = "Doe";

  public String getFirstName() {
    return firstName;
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }

  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public String showGreeting() {
    return "Hello " + firstName + " " + lastName + "!";
  }
}

pom.xml

<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>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>   

  <groupId>com.codenotfound</groupId>
  <artifactId>jsf-primefaces-apache-tomcat</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>JSF - PrimeFaces Hello World Example using Apache Tomcat and Maven</name>
  <url>https://www.codenotfound.com/jsf-primefaces-hello-world-example-apache-tomcat.html</url>


  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
    <jsf.version>2.2.15</jsf.version>
    <primefaces.version>6.1</primefaces.version>

    <maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
    <tomcat7-maven-plugin.version>2.2</tomcat7-maven-plugin.version>
  </properties>

    <dependencies>
    <!--  SPRING BOOT -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

  <!--  JSTL -->
    <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    </dependency>


    <!-- Servlet -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <scope>provided</scope>
    </dependency>

    <!-- JSF -->
    <dependency>
      <groupId>com.sun.faces</groupId>
      <artifactId>jsf-api</artifactId>
      <version>${jsf.version}</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>com.sun.faces</groupId>
      <artifactId>jsf-impl</artifactId>
      <version>${jsf.version}</version>
      <scope>compile</scope>
    </dependency>

    <!-- PrimeFaces -->
    <dependency>
      <groupId>org.primefaces</groupId>
      <artifactId>primefaces</artifactId>
      <version>${primefaces.version}</version>
    </dependency>

    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>      

  </dependencies>

   <build>
    <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <addResources>false</addResources>
                </configuration>
            </plugin>    
    </plugins>
  </build>

</project>

src/main/webapp/index.xhtml

<?xml version="1.0" encoding="UTF-8"?>
<!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:h="http://java.sun.com/jsf/html"
  xmlns:p="http://primefaces.org/ui">

<h:head>
  <title>PrimeFaces Hello World Example</title>
</h:head>

<h:body>
  <h:form>

    <p:panel header="PrimeFaces Hello World Example">
      <h:panelGrid columns="2" cellpadding="4">
        <h:outputText value="First Name: " />
        <p:inputText value="#{helloWorld.firstName}" />

        <h:outputText value="Last Name: " />
        <p:inputText value="#{helloWorld.lastName}" />

        <p:commandButton value="Submit" update="greeting"
          oncomplete="PF('greetingDialog').show()" />
      </h:panelGrid>
    </p:panel>

    <p:dialog header="Greeting" widgetVar="greetingDialog"
      modal="true" resizable="false">
      <h:panelGrid id="greeting" columns="1" cellpadding="4">
        <h:outputText value="#{helloWorld.showGreeting()}" />
      </h:panelGrid>
    </p:dialog>

  </h:form>
</h:body>
</html>

src/main/webapp/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
  version="3.1">

  <!-- File(s) appended to a request for a URL that is not mapped to a web component -->
  <welcome-file-list>
    <welcome-file>index.xhtml</welcome-file>
  </welcome-file-list>

</web-app>

src/main/webapp/WEB-INF/faces-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<faces-config
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
    version="2.2">
</faces-config>

【问题讨论】：

标签： spring spring-boot jsf propertynotfoundexception

【解决方案1】：

我正在等待有人指出为什么 JSF bean 管理不能与 @ManagedBean 一起使用。同时，我只是通过将原始 faces-config.xml 的内容替换为以下内容来使用 Spring bean 管理：-

faces-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<faces-config
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
    version="2.2">

    <application>
        <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
    </application>

</faces-config>

这将启用 Spring bean 管理，@ManagedBean 可以替换为 @Component（或任何其他 spring 注释）以使其工作（至少在这种情况下）。你可以阅读更多关于它的信息here。

附注仍在等待原始问题的解决方案。

【讨论】：