java - Maven + SLF4J : Version conflict when using two different dependencies that require two different SLF4J versions

Question

我有一个项目独立使用这两个依赖项:BoneCP 和 Hibernate。但是由于 SLF4J 及其版本冲突，它不起作用，因为 BoneCP 需要 SLF4J 1.5 而 Hibernate 需要 SLF4j 1.6。如您所知，不可能在 pom.xml 中对同一依赖项的两个不同版本进行重要处理。那么我能做些什么来解决这个惊人的 SLF4J 副作用？？？

我得到的错误是臭名昭著的:

SLF4J: The requested version 1.5.10 by your slf4j binding is not compatible with [1.6]
SLF4J: See http://www.slf4j.org/codes.html#version_mismatch for further details.

我需要添加这个，但是不允许有两个不同版本的相同依赖:

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.5.10</version>
<scope>provided</scope>
</dependency>   

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.6.2</version>
<scope>provided</scope>
</dependency>   

Maven 依赖树:

[INFO] [dependency:tree {execution: default-cli}]
[INFO] org.mentawai:menta:war:1.0.5-SNAPSHOT
[INFO] +- javax.servlet.jsp:jsp-api:jar:2.0:provided
[INFO] +- javax.servlet:servlet-api:jar:2.5:provided
[INFO] +- javax.activation:activation:jar:1.1:compile
[INFO] +- javax.mail:mail:jar:1.4:compile
[INFO] +- javax.persistence:persistence-api:jar:1.0:compile
[INFO] +- org.slf4j:slf4j-log4j12:jar:1.5.10:compile
[INFO] |  +- org.slf4j:slf4j-api:jar:1.5.10:compile
[INFO] |  \- log4j:log4j:jar:1.2.14:compile
[INFO] +- org.hibernate:hibernate-core:jar:3.6.7.Final:compile
[INFO] |  +- antlr:antlr:jar:2.7.6:compile
[INFO] |  +- commons-collections:commons-collections:jar:3.1:compile
[INFO] |  +- dom4j:dom4j:jar:1.6.1:compile
[INFO] |  +- org.hibernate:hibernate-commons-annotations:jar:3.2.0.Final:compile
[INFO] |  +- org.hibernate.javax.persistence:hibernate-jpa-2.0-api:jar:1.0.1.Final:compile
[INFO] |  \- javax.transaction:jta:jar:1.1:compile
[INFO] +- javassist:javassist:jar:3.12.1.GA:compile
[INFO] +- junit:junit:jar:4.8.1:test
[INFO] +- c3p0:c3p0:jar:0.9.1.2:compile
[INFO] +- com.h2database:h2:jar:1.2.138:compile
[INFO] +- mysql:mysql-connector-java:jar:5.1.13:compile
[INFO] +- me.soliveirajr:mentawai:jar:2.3.3-SNAPSHOT:compile
[INFO] |  +- net.sf.json-lib:json-lib:jar:jdk15:2.3:compile
[INFO] |  |  +- commons-beanutils:commons-beanutils:jar:1.8.0:compile
[INFO] |  |  +- commons-logging:commons-logging:jar:1.1.1:compile
[INFO] |  |  \- net.sf.ezmorph:ezmorph:jar:1.0.6:compile
[INFO] |  +- org.jdom:jdom:jar:1.1:compile
[INFO] |  +- com.thoughtworks.xstream:xstream:jar:1.3.1:compile
[INFO] |  |  \- xpp3:xpp3_min:jar:1.1.4c:compile
[INFO] |  +- org.ajaxtags:ajaxtags:jar:1.2-beta3:compile
[INFO] |  |  +- javax.servlet:jstl:jar:1.0.6:compile
[INFO] |  |  +- taglibs:standard:jar:1.0.6:compile
[INFO] |  |  \- net.htmlparser:jericho-html:jar:2.1:compile
[INFO] |  +- jgroups:jgroups-all:jar:2.2.9.1:compile
[INFO] |  +- me.soliveirajr:menta-container:jar:0.9.8:compile
[INFO] |  +- me.soliveirajr:menta-bean:jar:1.1.1:compile
[INFO] |  +- me.soliveirajr:menta-regex:jar:0.9.5:compile
[INFO] |  +- org.beanshell:bsh:jar:2.0b4:compile
[INFO] |  +- com.jolbox:bonecp:jar:0.7.1.RELEASE:compile
[INFO] |  |  \- com.google.guava:guava:jar:r08:compile
[INFO] |  +- velocity:velocity-dep:jar:1.4:compile
[INFO] |  +- commons-fileupload:commons-fileupload:jar:1.2.2:compile
[INFO] |  +- commons-io:commons-io:jar:1.3.2:compile
[INFO] |  +- net.tanesha.recaptcha4j:recaptcha4j:jar:0.0.7:compile
[INFO] |  \- commons-dbcp:commons-dbcp:jar:1.4:compile
[INFO] |     \- commons-pool:commons-pool:jar:1.5.4:compile
[INFO] +- commons-lang:commons-lang:jar:2.5:compile
[INFO] \- asm:asm:jar:3.2:compile

Answer 1

错误消息中提供的链接“http://www.slf4j.org/codes.html#version_mismatch”指出:

An SLF4J binding designates an artifact such as slf4j-jdk14.jar or slf4j-log4j12.jar used to bind slf4j to an underlying logging framework, say, java.util.logging or log4j. Mixing mixing different versions of slf4j-api.jar and SLF4J binding can cause problems. For example, if you are using slf4j-api-1.6.6.jar, then you should also use slf4j-simple-1.6.6.jar, using slf4j-simple-1.5.5.jar will not work.

NOTE From the client's perspective all versions of slf4j-api are compatible. Client code compiled with slf4j-api-N.jar will run perfectly fine with slf4j-api-M.jar for any N and M. You only need to ensure that the version of your binding matches that of the slf4j-api.jar. You do not have to worry about the version of slf4j-api.jar used by a given dependendency in your project. You can always use ANY version of slf4j-api.jar, and as long as the version of slf4j-api.jar and its binding match, you should be fine.

鉴于 slf4j-api 的所有版本从客户端的角度来看都是可互换的，在不同版本的 slf4j-api 及其绑定(bind)的场景中，例如slf4j-log4j12 被拉入，在你的 POM 中显式声明它们为依赖项，如下所示:

<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-api</artifactId>
  <version>1.7.25</version>
</dependency>   

<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
  <version>1.7.25</version>
</dependency>   

这里我假设您实际上不需要在提供的范围内声明 slf4j-api 和 slf4j-log4j12。

另见 Introduction to the Dependency Mechanism其中指出:

Dependency mediation - this determines what version of a dependency will be used when multiple versions of an artifact are encountered. Currently, Maven 2.0 only supports using the "nearest definition" which means that it will use the version of the closest dependency to your project in the tree of dependencies. You can always guarantee a version by declaring it explicitly in your project's POM.