带有 JSTL 的嵌入式 Tomcat 上的 Spring Boot 仍然抛出 java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config

Question

我有一个利用 PrimeFaces、弹性搜索、Spring boot 的应用程序。

下面是pom.xml，

<?xml version="1.0" encoding="UTF-8"?>
<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>

    <groupId>com.acn.hps.aops.demo</groupId>
    <artifactId>PSCommandCenter</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>CommandCentre</name>
    <description>Command Center Application</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.3.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.6</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.google.code.geocoder-java</groupId>
            <artifactId>geocoder-java</artifactId>
            <version>0.16</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.3.2</version>
        </dependency>

        <!-- Primefaces -->
        <dependency>
            <groupId>org.primefaces</groupId>
            <artifactId>primefaces</artifactId>
            <version>5.2</version>
        </dependency>

        <dependency>
            <groupId>org.primefaces.themes</groupId>
            <artifactId>all-themes</artifactId>
            <version>1.0.10</version>
        </dependency>

        <dependency>
            <groupId>org.atmosphere</groupId>
            <artifactId>atmosphere-runtime</artifactId>
            <version>2.3.4</version>
        </dependency>

        <!-- JSF dependencies -->
        <dependency>
            <groupId>com.sun.faces</groupId>
            <artifactId>jsf-api</artifactId>
            <version>2.2.8</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.sun.faces</groupId>
            <artifactId>jsf-impl</artifactId>
            <version>2.2.8</version>
            <scope>compile</scope>
            <optional>true</optional>
        </dependency>

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

        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>

        <!-- Elastic Search dependencies -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-elasticsearch</artifactId>
        </dependency>

        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>1.7.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
          <groupId>com.opencsv</groupId>
          <artifactId>opencsv</artifactId>
          <version>3.7</version>
        </dependency>
    </dependencies>

    <repositories>
        <repository>
            <id>primefaces</id>
            <url>http://repository.primefaces.org</url>
        </repository>
    </repositories>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <executable>true</executable>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

下面是它的弹簧配置，

@SpringBootApplication
public class CommandCentreApplication extends WebMvcConfigurerAdapter{
    public static void main(String[] args) {
        SpringApplication.run(CommandCentreApplication.class, args);
    }
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("forward:/home.jsf");
    }
    @Bean
    ServletRegistrationBean facesServletRegistration() {
        return new ServletRegistrationBean() {
            @Override
            public void onStartup(ServletContext servletContext)
                    throws ServletException {
                FacesInitializer facesInitializer = new FacesInitializer();
                facesInitializer.onStartup(Collections.singleton(CommandCentreApplication.class),
                        servletContext);
                servletContext.setInitParameter("primefaces.THEME", "redmond");
                servletContext.setInitParameter("javax.faces.FACELETS_REFRESH_PERIOD", "0");
                servletContext.setInitParameter("facelets.SKIP_COMMENTS", "true");
            }
        };
    }
    @Bean
    ServletRegistrationBean pushServletRegistration(){
        ServletRegistrationBean pushServlet = new ServletRegistrationBean(new PushServlet(), "/primepush/*");
        pushServlet.addInitParameter("org.atmosphere.annotation.packages", "org.primefaces.push");
        pushServlet.addInitParameter("org.atmosphere.cpr.packages", "com.acn.hps.aops.demo.map.service.channel");
        pushServlet.setAsyncSupported(true);
        pushServlet.setLoadOnStartup(0);
        pushServlet.setOrder(Ordered.HIGHEST_PRECEDENCE);
        return pushServlet;
    }
}

还有我的弹性搜索的配置，

@Bean
 public Client client(){
     TransportClient client= new TransportClient();
     TransportAddress address = new InetSocketTransportAddress(PropertiesLoader.esIP, PropertiesLoader.esPort);
     client.addTransportAddress(address);
     return client;
 }

当我从我的 IDE (Eclipse) 执行该应用程序时，它会按预期运行，但是当我从它的 jar 执行应用程序时，我会收到以下异常，

java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config 在 java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_45].

我搜索了这个异常，发现添加了jstl的jar来避免这个错误。但是我在tomcat的罐子里已经有了jstl的罐子。而且，如果这是问题所在，那么我应该在从我的 IDE 执行时遇到相同的异常。

您可以参考我用作应用程序大纲的this github 代码。我也面临同样的问题。

Answer 1

当使用spring-boot-starter作为父级时，运行

mvn clean install

应该生成一个胖 jar（这意味着所有依赖项都复制到该 jar 中）。 更多信息可以在这里找到： https://docs.spring.io/spring-boot/docs/current/reference/html/howto-build.html

也许这部分在 pom.xml 中的 spring-boot-starter 插件中

<configuration>
    <executable>true</executable>
</configuration>

搞砸了。尝试删除该部分并重新构建 jar。