使用 Zuul 代理的 Spring Boot 在 Maven 上崩溃，而 Gradle 工作

Question

我有一个使用 Gradle 构建的 Spring Boot 项目。

我需要将它迁移到 Maven，我认为这很容易（应该），但我遇到了 Zuul 依赖问题，或者准确地说：spring-cloud-starter-zuul。

当我运行带有注释 @EnableZuulProxy 的 Spring Boot 应用程序时，它会产生以下错误：

2017-03-30 00:02:57.521  WARN 11380 --- [ost-startStop-1] c.n.c.sources.URLConfigurationSource     : No URLs will be polled as dynamic configuration sources.
2017-03-30 00:02:57.521  INFO 11380 --- [ost-startStop-1] c.n.c.sources.URLConfigurationSource     : To enable URLs as dynamic configuration sources, define System property archaius.configurationSource.additionalUrls or make config.properties available on classpath.
2017-03-30 00:02:57.532  INFO 11380 --- [ost-startStop-1] c.netflix.config.DynamicPropertyFactory  : DynamicPropertyFactory is initialized with configuration sources: com.netflix.config.ConcurrentCompositeConfiguration@df85e3e
2017-03-30 00:02:57.556 ERROR 11380 --- [ost-startStop-1] o.s.b.c.embedded.tomcat.TomcatStarter    : Error starting Tomcat context. Exception: org.springframework.beans.factory.UnsatisfiedDependencyException. Message: Error creating bean with name 'org.springframework.cloud.netflix.zuul.ZuulConfiguration$ZuulFilterConfiguration': Unsatisfied dependency expressed through field 'filters'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'simpleHostRoutingFilter' defined in org.springframework.cloud.netflix.zuul.ZuulProxyConfiguration: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter]: Factory method 'simpleHostRoutingFilter' threw exception; nested exception is java.lang.NoClassDefFoundError: org/apache/http/conn/HttpClientConnectionManager
2017-03-30 00:02:57.588  WARN 11380 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
2017-03-30 00:02:57.588 ERROR 11380 --- [           main] o.s.boot.SpringApplication               : Application startup failed

该错误仅发生在 Maven 构建上，这将问题缩小到 pom.xml 文件与确实运行的 build.gradle。

在修改了工作 build.gradle 文件后，我在注释掉这部分时设法产生了错误：

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.3.RELEASE")
    }
}
apply plugin: 'org.springframework.boot'

所以问题是我没有在我的 maven 文件中使用插件？

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>aaa</groupId>
    <artifactId>helloZuul</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>1.4.3.RELEASE</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>1.4.3.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-io -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-io</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-zuul -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zuul</artifactId>
            <version>1.2.6.RELEASE</version>
        </dependency>
    </dependencies>
</project>

build.gradle

group 'aaa'
version '1.0-SNAPSHOT'

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.3.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'idea'
apply plugin: 'org.springframework.boot'
apply plugin: 'war'

sourceCompatibility = 1.8

jar {
    baseName = 'gs-rest-service'
    version = '0.1.0'
}

repositories {
    mavenCentral()
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
    compile "org.springframework.boot:spring-boot-starter-web:1.4.3.RELEASE"
    compile group: 'org.apache.commons', name: 'commons-io', version: '1.3.2'
    compile group: 'org.springframework.cloud', name: 'spring-cloud-starter-zuul', version: '1.2.6.RELEASE'
}

如何让我的 Maven 项目运行？或者更具体地说，spring boot gradle 插件的用途是什么？

任何帮助将不胜感激！

Answer 1

经过多次尝试和错误，我设法让它工作。

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>aaa</groupId>
    <artifactId>client</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zuul</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

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

        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-io -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-io</artifactId>
            <version>1.3.2</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

Answer 2

您需要在 pom.xml 中添加依赖管理，如下所示。

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Camden.SR6</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>