java 9模块从A和B读取包X

Question

我正在尝试将 spring boot 与 java 9 和 gradle 一起使用。 我无法运行我的简单代码，出现以下错误：-

Information:java: Errors occurred while compiling module 'Java9Gradle_main'
Information:javac 9-ea was used to compile java sources
Information:6/9/2017 10:40 PM - Compilation completed with 65 errors and 0 warnings in 15s 200ms
Error:java: module  reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module  reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.web reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.web reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.autoconfigure reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.autoconfigure reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.logging reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.logging reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.core reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.core reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module snakeyaml reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module snakeyaml reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.tomcat reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter.tomcat reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module hibernate.validator reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module hibernate.validator reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jackson.databind reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jackson.databind reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.web reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.web reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.webmvc reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.webmvc reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.context reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.context reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module logback.classic reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module logback.classic reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jcl.over.slf4j reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jcl.over.slf4j reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jul.to.slf4j reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jul.to.slf4j reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module log4j.over.slf4j reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module log4j.over.slf4j reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module commons.logging reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module commons.logging reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.core reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.core reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.el reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.el reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.websocket reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module tomcat.embed.websocket reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module validation.api reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module validation.api reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jboss.logging reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jboss.logging reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module classmate reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module classmate reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jackson.annotations reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jackson.annotations reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module jackson.core reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module jackson.core reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.aop reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.aop reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.beans reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.beans reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.expression reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.expression reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module logback.core reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module logback.core reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module slf4j.api reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module slf4j.api reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot.starter reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging
Error:java: module spring.boot reads package org.apache.commons.logging.impl from both jcl.over.slf4j and commons.logging
D:\project\Java9Gradle\src\main\java\module-info.java
Error:(1, 1) java: module Java9Gradle.main reads package org.apache.commons.logging from both jcl.over.slf4j and commons.logging

我的依赖文件和 module-info.java 文件非常简单。

module Java9Gradle.main {
    requires spring.boot;
}


group 'Java9Gradle'
version '1.0-SNAPSHOT'

apply plugin: 'java'

sourceCompatibility = 1.9

repositories {
    mavenCentral()
}

dependencies {
    // https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter
    compile group: 'org.springframework.boot', name: 'spring-boot-starter', version: '1.5.3.RELEASE'
    // https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-web', version: '1.5.3.RELEASE'
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

有人可以帮忙吗？

谢谢，

阿马尔

Answer 1

此类问题发生在多个库中，例如 Apache Mina (sshd-core)，其中 sshd-core 和 sshd-common 之间存在拆分。与 Springfox Swagger 2 类似，您可以在其中遇到类似的拆分包问题：“Module XXX 从 springfox.core 和 springfox.spi 读取包 springfox.documentation 服务。”

在分析了如何克服它的多种方法后，我找到了一种适用于所有情况的解决方案。

这个想法是将有问题的库重新打包到单个 jar 中，然后将它们安装到您的公司（或本地存储库）中。如果您有公司范围的 nexus，则可以安装它，否则在运行整个构建之前，您可以手动将此类库安装到本地 maven 存储库。

虽然这些看起来有点矫枉过正，而且不容易做到，但实际上很容易。

您需要在主项目中创建新的 maven 模块（如果您没有运行多模块项目，则需要创建单独的 maven 项目）。然后将引入包拆分的依赖项添加到您的 pom.xml 并配置 maven 程序集插件以重新打包它们。

对于 spring-fox，这将是

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>3.2.0</version>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
                <appendAssemblyId>false</appendAssemblyId>
            </configuration>
            <executions>
                <execution>
                    <id>make-assembly</id>
                    <phase>package</phase>
                    <goals>
                        <goal>single</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

<dependencies>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-core</artifactId>
        <version>${io.springfox.version}</version>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>${io.springfox.version}</version>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-spring-webmvc</artifactId>
        <version>${io.springfox.version}</version>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-schema</artifactId>
        <version>${io.springfox.version}</version>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-spring-web</artifactId>
        <version>${io.springfox.version}</version>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-spi</artifactId>
        <exclusions>
            <exclusion>
                <groupId>*</groupId>
                <artifactId>*</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

</dependencies>

请注意两件事。首先<appendAssemblyId>false</appendAssemblyId> 作为程序集插件的配置参数。第二次排除所有瞬态依赖，使它们不会被包含到最终包中。

准备好 pom.xml 后，您可以转到新模块目录并运行 clean install 或 clean package 以创建一个包，并将所有依赖项编译到单个 jar 中。 jar 将位于您的目标文件夹下。这样您将创建您命名的文件，例如springfox-all-3.0.0.jar（包含单个模块中的所有springfox代码）。

现在您可以将此软件包安装到本地仓库中，或者更好地将其部署到您的 nexus，例如使用以下命令

mvn deploy:deploy-file -Dversion=3.0.0-SNAPSHOT -Durl=http://nexus.youc.company.net/nexus/content/repositories/yourRepoId -Dfile=springfox-all-3.0.0.jar -DgroupId=patched.io.springfox -DrepositoryId=yourRepoId -DartifactId=springfox-all

现在在你的 pom.xml 文件和你的 module-info.java 中使用这个依赖而不是你项目中的单个依赖集

module com.acme.your.module {

//  requires springfox.spring.web;
//  requires springfox.swagger2;
//  requires springfox.core;
//  requires springfox.spi;
  requires springfox.all;
}

Answer 2

根据Jigsaw specs

无干扰——Java 编译器、虚拟机和运行时 系统必须确保包含同名包的模块 不要互相干扰。如果两个不同的模块包含 那么，从每个模块的角度来看，同名的包， 该包中的所有类型和成员仅由该包定义 模块。一个模块中该包中的代码不能访问 包私有类型或其他模块中该包中的成员。

这在@Andy here 的回答中被称为拆分包。因此解决方案是解开这些包，并确保您的模块jcl.over.slf4j 和commons.logging 中包含的包只能通过一个模块访问。

---

您可以分析 spring-boot-starter:1.5.3.RELEASE 和 spring-boot-starter-web:1.5.3.RELEASE 这两个依赖项，以确保您的项目中包含这两个模块中的任何一个。

Answer 3

排除传递依赖使其工作并调整module-info.java!!!

compile("org.springframework.boot:spring-boot-starter:1.5.3.RELEASE") {
        exclude group: 'commons-logging', module: 'commons-logging'
    }
    compile("org.springframework.boot:spring-boot-starter-web:1.5.3.RELEASE"){
        exclude group: 'commons-logging', module: 'commons-logging'
    }