Spring Cloud Netflix 1.0.0 RC2 破解应用

Question

我有一个可以在 Spring Cloud Netflix 1.0.0.RC1 上正常运行的应用程序。当我升级同一个项目以使用 RC2 工件时，在应用程序启动期间出现以下异常。

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:53)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor': Invocation of init method failed; nested exception is javax.validation.ValidationException: Unable to instantiate Configuration.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1566)
 ....
    Caused by: javax.validation.ValidationException: Unable to instantiate Configuration.
    at javax.validation.Validation$GenericBootstrapImpl.configure(Validation.java:279)
    at org.springframework.validation.beanvalidation.LocalValidatorFactoryBean.afterPropertiesSet(LocalValidatorFactoryBean.java:223)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor$Jsr303ValidatorFactory.run(ConfigurationPropertiesBindingPostProcessor.java:381)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.afterPropertiesSet(ConfigurationPropertiesBindingPostProcessor.java:174)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1625)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562)
    ... 29 more
Caused by: javax.validation.ValidationException: HV000183: Unable to load 'javax.el.ExpressionFactory'. Check that you have the EL dependencies on the classpath
    at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.<init>(ResourceBundleMessageInterpolator.java:172)
    at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.<init>(ResourceBundleMessageInterpolator.java:118)
    at org.hibernate.validator.internal.engine.ConfigurationImpl.<init>(ConfigurationImpl.java:110)
    at org.hibernate.validator.internal.engine.ConfigurationImpl.<init>(ConfigurationImpl.java:86)
    at org.hibernate.validator.HibernateValidator.createGenericConfiguration(HibernateValidator.java:41)
    at javax.validation.Validation$GenericBootstrapImpl.configure(Validation.java:276)

POM 文件如下所示：

<?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.sample</groupId>
    <artifactId>sample-service</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>Sample Service</name>
    <description>Sample Service</description>

    <parent>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-parent</artifactId>
        <version>1.0.0.RC2</version>
        <relativePath />
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bus-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-netflix-hystrix-amqp</artifactId>
        </dependency>
    </dependencies>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>com.sample.SampleServiceApplication</start-class>
        <java.version>1.8</java.version>
    </properties>

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

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>http://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>

使用 RC1 作为版本的 POM 文件可以正常工作。我尝试手动将 javax.el:javax.el-api:2.2.4 添加到 POM，但是由于存在该依赖关系，Tomcat 无法正常启动（日志中没有错误，但也没有 Tomcat 启动）。

Answer 1

通过将以下依赖项添加到 POM 文件来实现此功能。

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

似乎从 RC2 开始，我们需要显式添加 Tomcat Starter 作为依赖项。