Maven重复类的解决

1. 设置仓库,我的Settings里设置使用了公司的Nexus

<?xml version="1.0"?>
<settings 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/settings-1.0.0.xsd">

    <localRepository>D:\mavenrepo</localRepository>

    <servers>
        <server>
            <id>snapshots</id>
            <username>snapshots</username>
            <password>xxx</password>
            <filePermissions>664</filePermissions>
            <directoryPermissions>775</directoryPermissions>
        </server>
    </servers>

    <distributionManagement>
        <repository>
            <id>releases</id>
            <name>xxx Nexus Releases</name>
            <url>xxxx</url>
        </repository>
        <snapshotRepository>
            <uniqueVersion>false</uniqueVersion>
            <id>snapshots</id>
            <name>xxx Nexus Snapshots</name>
            <url>xxxxx</url>
        </snapshotRepository>
    </distributionManagement>
    <profiles>
        <profile>
            <id>xxxNexus</id>
            <repositories>
                <repository>
                    <id>xxxNexus</id>
                    <url>xxx</url>
                    <releases>
                        <enabled>true</enabled>
                        <!-- always , daily (default), interval:X (where X is an integer in minutes) or never. -->
                        <updatePolicy>daily</updatePolicy>
                        <checksumPolicy>warn</checksumPolicy>
                    </releases>
                    <snapshots>
                        <enabled>true</enabled>
                        <checksumPolicy>fail</checksumPolicy>
                    </snapshots>
                </repository>
            </repositories>
            <pluginRepositories>
                <pluginRepository>
                    <id>xxxNexus</id>
                    <url>xxxx</url>
                    <releases>
                        <enabled>true</enabled>
                        <checksumPolicy>warn</checksumPolicy>
                    </releases>
                    <snapshots>
                        <enabled>true</enabled>
                        <checksumPolicy>fail</checksumPolicy>
                    </snapshots>
                </pluginRepository>
            </pluginRepositories>
        </profile>
    </profiles>

    <activeProfiles>
        <activeProfile>xxxNexus</activeProfile>
    </activeProfiles>

</settings>

2.发现重复类,执行命令

mvn -U clean package -Plocal -Dmaven.test.skip=true enforcer:enforce -DcheckDeployRelease_skip=true

-Dmaven.test.skip=true: 如果命令包含了test phase，则忽略单元测试

enforcer:enforce: 查找重复类

-DcheckDeployRelease_skip: 不知道什么意思

执行命令后,输出如下

可以发现 jcl-over-slf4j 与 commons-logging 包有重复类冲突

3. 在pom里查找重复类冲突的包并排除重复类冲突

由于在我的pom里并没有显式写入common-logging的dependency,所以我们需要查找那个jar包依赖了commons-logging,执行如下命令

mvn -U dependency:tree -Dverbose

发现如下片段

在这个叫qsso-client的库里依赖了commons-logging包,所以我们在pom里将其排除

3. 排除重复类

            <dependency>
                <groupId>com.xxx.security</groupId>
                <artifactId>qsso-client</artifactId>
                <version>${qsso-client.version}</version>
                <exclusions>
                    <exclusion>
                        <groupId>commons-logging</groupId>
                        <artifactId>commons-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

这样就将qsso-client的commons-logging包排除了,之后再运行enforcer:enforce则不会再报错