将slf4j api和实现放在多模块Java EE项目中的位置？

Question

由于（Maven）依赖关系管理，我知道在类路径上丢失或重复slf4j实现的原因，并且知道如何通过排除来避免这种情况。

但是，如果我有一个包含EJB接口和实体的JAR的多模块Java项目，EJB实现和打包为EAR的WAR Web前端，我找不到放置slf4j API org.slf4j:slf4j-api:1.7.25的方法，实现ch.qos.logback:logback-classic:1.2.3和配置logback.xml，以便我在JAR，EJB和WEB模块中工作，并且可以避免这两者

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

和

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/richter/zpool-tmp/jee-slf4j-logging/jee-slf4j-logging-ear/target/gfdeploy/jee-slf4j-logging-ear/jee-slf4j-logging-web-1.0-SNAPSHOT_war/WEB-INF/lib/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/richter/zpool-tmp/jee-slf4j-logging/jee-slf4j-logging-ear/target/gfdeploy/jee-slf4j-logging-ear/lib/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [ch.qos.logback.classic.util.ContextSelectorStaticBinder]

和

Caused by: java.lang.LinkageError: loader constraint violation: when resolving method "org.slf4j.impl.StaticLoggerBinder.getLoggerFactory()Lorg/slf4j/ILoggerFactory;" the class loader (instance of org/glassfish/web/loader/WebappClassLoader) of the current class, org/slf4j/LoggerFactory, and the class loader (instance of org/glassfish/javaee/full/deployment/EarLibClassLoader) for the method's defining class, org/slf4j/impl/StaticLoggerBinder, have different Class objects for the type org/slf4j/ILoggerFactory used in the signature
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:418)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)

我在https://gitlab.com/krichter/jee-slf4j-logging提供MCVE。

GlassFish 4, no logging framework dependencies is working in pom.xml不涉及Java EE方面。

Answer 1

我最后做了以下事情：

1. 直接在EAR文件夹下创建一个新文件夹。例如，创建一个名为“conf” - > EAR / conf的新文件夹
2. 将logback.xml文件放在这个新文件夹中：EAR / conf / logback.xml
3. 在WAR / EJB / API文件的MANIFEST.MF文件中，将此新文件夹添加到类路径中：

Class-Path: conf

如果您使用maven在您的moules（例如web，ejb和ejb接口）中构建项目，请将依赖性添加到具有提供范围的slf4j-api：

WEB, EJB, API modules
<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-api</artifactId>
  <version>${slf4j.version}</version>
  <scope>provided</scope>
</dependency>

并在您的EAR模块中添加依赖项到slf4j-api和logback-classic和logback-core：

EAR modeule
<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-api</artifactId>
  <version>${slf4j.version}</version>
</dependency>

<dependency>
  <groupId>ch.qos.logback</groupId>
  <artifactId>logback-classic</artifactId>
  <version>${logback.version}</version>
</dependency>

<dependency>
  <groupId>ch.qos.logback</groupId>
  <artifactId>logback-core</artifactId>
  <version>${logback.version}</version>
</dependency>

要在模块中将conf定义为Class-Path，请在maven-war-plugin，maven-jar-plugin和maven-ejb-plugin中使用以下行。

WEB, EJB, API modules
<configuration>
  <archive>
    <addMavenDescriptor>false</addMavenDescriptor>
    <manifest>
      <addClasspath>true</addClasspath>
    </manifest>
    <manifestEntries>
      <Class-Path>logback</Class-Path>
    </manifestEntries>
  </archive>
...