SLF4J 오류 해결

갑자기 잘 돌아 가던 프로젝트가 아래 오류를 내면서 뻗는다.

-------------

SLF4J: Class path contains multiple SLF4J bindings.

SLF4J: Found binding in [jar:file:/Users/chaehyun/.m2/repository/org/slf4j/slf4j-log4j12/1.4.3/slf4j-log4j12-1.4.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: Found binding in [jar:file:/Users/chaehyun/.m2/repository/org/slf4j/slf4j-simple/1.7.2/slf4j-simple-1.7.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]

SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.

SLF4J: slf4j-api 1.6.x (or later) is incompatible with this binding.

SLF4J: Your binding is version 1.5.5 or earlier.

SLF4J: Upgrade your binding to version 1.6.x.

---------------

뭔가 slf4j 관련 library 버전이 꼬였나 보다. 이런 젠-_-장.. 난 maven도 잘 모르는데.. 흑..

인터넷을 뒤져보니, 아래 명령어를 통해서 꼬인 버전을 찾아 보랜다.

mvn dependency:tree -Dverbose -Dincludes=org.slf4j

--------

[INFO] com.recopick.coruscant:coruscant:jar:0.1

[INFO] +- net.sf.uadetector:uadetector-resources:jar:2013.02:compile

[INFO] |  +- net.sf.uadetector:uadetector-core:jar:0.9.2:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.7.2:compile - omitted for duplicate)

[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.2:compile

[INFO] +- org.apache.hadoop:hadoop-client:jar:2.0.0-mr1-cdh4.3.0:provided

[INFO] |  \- org.apache.hadoop:hadoop-common:jar:2.0.0-cdh4.3.0:provided

[INFO] |     +- (org.slf4j:slf4j-api:jar:1.6.1:provided - omitted for conflict with 1.7.2)

[INFO] |     +- (org.slf4j:slf4j-log4j12:jar:1.6.1:provided - omitted for conflict with 1.4.3)

[INFO] |     \- org.apache.avro:avro:jar:1.7.4:provided

[INFO] |        \- (org.slf4j:slf4j-api:jar:1.6.4:provided - omitted for conflict with 1.7.2)

[INFO] +- org.apache.hadoop:hadoop-test:jar:2.0.0-mr1-cdh4.3.0:compile

[INFO] |  +- org.apache.mina:mina-core:jar:2.0.0-M5:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.5.2:compile - omitted for conflict with 1.7.2)

[INFO] |  +- org.apache.ftpserver:ftpserver-core:jar:1.0.0:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.5.2:compile - omitted for conflict with 1.7.2)

[INFO] |  \- org.apache.ftpserver:ftpserver-deprecated:jar:1.0.0-M2:compile

[INFO] |     \- (org.slf4j:slf4j-api:jar:1.5.2:compile - omitted for conflict with 1.7.2)

[INFO] +- org.apache.hbase:hbase:jar:0.94.6-cdh4.3.0:compile

[INFO] |  +- com.yammer.metrics:metrics-core:jar:2.1.2:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.6.4:compile - omitted for conflict with 1.7.2)

[INFO] |  +- org.apache.thrift:libthrift:jar:0.9.0:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.5.8:compile - omitted for conflict with 1.7.2)

[INFO] |  +- (org.slf4j:slf4j-api:jar:1.4.3:compile - omitted for conflict with 1.7.2)

[INFO] |  \- org.slf4j:slf4j-log4j12:jar:1.4.3:compile

[INFO] |     \- (org.slf4j:slf4j-api:jar:1.4.3:compile - omitted for conflict with 1.7.2)

[INFO] +- org.apache.mahout:mahout-core:jar:0.7-cdh4.3.0:compile

[INFO] |  +- org.apache.mahout:mahout-math:jar:0.7-cdh4.3.0:compile

[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.6.1:compile - omitted for conflict with 1.7.2)

[INFO] |  \- (org.slf4j:slf4j-api:jar:1.6.1:compile - omitted for conflict with 1.7.2)

[INFO] +- org.slf4j:slf4j-simple:jar:1.7.2:compile

[INFO] |  \- (org.slf4j:slf4j-api:jar:1.7.2:compile - omitted for duplicate)

[INFO] \- org.apache.oozie:oozie-client:jar:3.1.3-cdh4.0.1:compile

[INFO]    \- org.apache.hadoop:hadoop-auth:jar:2.0.0-cdh4.0.1:compile

[INFO]       \- (org.slf4j:slf4j-log4j12:jar:1.6.1:compile - omitted for conflict with 1.4.3)

----------------

눈을 크게 뜨고 보면, org.apache.hbase:hbase:jar 에서 문제의 1.4.3 버전을 로딩하는 것 같다. http://www.slf4j.org/codes.html 링크에 보면 친절하게 해결책이 나와 있다. 아래와 같이 pom.xml을 수정하여 특정 library에서 1.4.3을 쓰지 않도록 명시적으로 exclude를 해 주면 됨.

-----

    <dependency>

      <groupId>org.apache.hbase</groupId>

      <artifactId>hbase</artifactId>

      <version>0.94.6-cdh4.3.0</version>

      <exclusions>

        <exclusion>

          <artifactId>maven-release-plugin</artifactId>

          <groupId>org.apache.maven.plugins</groupId>

        </exclusion>

        <exclusion>

          <groupId>org.slf4j</groupId>

          <artifactId>slf4j-log4j12</artifactId>

        </exclusion>

        <exclusion>

          <groupId>log4j</groupId>

          <artifactId>log4j</artifactI>

        </exclusion>

      </exclusions>

    </dependency>

----

eclipse를 쓰는 경우, 

mvn eclipse:eclipse 를 해 준다음, eclipse를 refresh 해주면 정상동작함..

1시간 삽질했음..