I'm getting the following error. It seems there are multiple logging frameworks bound to slf4j. Not sure how to resolve this. Any help is greatly appreciated.
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/admin/.m2/repository/org/slf4j/slf4j-log4j12/1.6.4/slf4j-log4j12-1.6.4.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/admin/.m2/repository/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Resolved by adding the following exclusion in the dependencies (of pom.xml) that caused conflict.
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
Gradle version;
configurations.all {
exclude module: 'slf4j-log4j12'
}
The error probably gives more information like this (although your jar names could be different)
SLF4J: Found binding in
[jar:file:/D:/Java/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in
[jar:file:/D:/Java/repository/org/apache/logging/log4j/log4j-slf4j-impl/2.8.2/log4j-slf4j-impl-2.8.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
Noticed that the conflict comes from two jars, named logback-classic-1.2.3 and log4j-slf4j-impl-2.8.2.jar.
Run mvn dependency:tree in this project pom.xml parent folder, giving:
Now choose the one you want to ignore (could consume a delicate endeavor I need more help on this)
I decided not to use the one imported from spring-boot-starter-data-jpa (the top dependency) through spring-boot-starter and through spring-boot-starter-logging, pom becomes:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
in above pom spring-boot-starter-data-jpa would use the spring-boot-starter configured in the same file, which excludes logging (it contains logback)
Sbt version:
Append exclude("org.slf4j", "slf4j-log4j12") to the dependency that transitively includes slf4j-log4j12. For example, when using Spark with Log4j 2.6:
libraryDependencies ++= Seq(
// One SLF4J implementation (log4j-slf4j-impl) is here:
"org.apache.logging.log4j" % "log4j-api" % "2.6.1",
"org.apache.logging.log4j" % "log4j-core" % "2.6.1",
"org.apache.logging.log4j" % "log4j-slf4j-impl" % "2.6.1",
// The other implementation (slf4j-log4j12) would be transitively
// included by Spark. Prevent that with exclude().
"org.apache.spark" %% "spark-core" % "1.5.1" exclude("org.slf4j", "slf4j-log4j12")
)
1.Finding the conflicting jar
If it's not possible to identify the dependency from the warning, then you can use the following command to identify the conflicting jar
mvn dependency: tree
This will display the dependency tree for the project and dependencies who have pulled in another binding with the slf4j-log4j12 JAR.
Resolution
Now that we know the offending dependency, all that we need to do is exclude the slf4j-log4j12 JAR from that dependency.
Ex - if spring-security dependency has also pulled in another binding with the slf4j-log4j12 JAR, Then we need to exclude the slf4j-log4j12 JAR from the spring-security dependency.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
Note - In some cases multiple dependencies have pulled in binding with the slf4j-log4j12 JAR and you don't need to add exclude for each and every dependency that has pulled in.
You just have to do that add exclude dependency with the dependency which has been placed at first.
Ex -
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
</dependencies>
If you work with gradle then add following code to your build.gradle file to exclude SLF4J binding from all the modules
configurations.all {
exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging'
}
I just ignored/removed that jar file.
<!--<dependency>-->
<!--<groupId>org.springframework.boot</groupId>-->
<!--<artifactId>spring-boot-starter-log4j2</artifactId>-->
<!--</dependency>-->
I solved by delete this:spring-boot-starter-log4j2
Just use only required dependency, not all :))). For me, for normal work of logging process you need this dependency exclude others from pom.xml
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.8</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.1.8</version>
</dependency>
This is issue because of StaticLoggerBinder.class class belongs to two different jars. this class references from logback-classic-1.2.3.jar and same class also referenced from log4j-slf4j-impl-2.10.0.jar. both of jar in classpath. Hence there is conflict between them.
This is reason of log file is not generation even though log4j2.xml file in classpath [src/main/resource].
We have so select one of jar, I recommend use log4j-slf4j-impl-2.10.0.jar file and exclude logback-classic-1.2.3.jar file.
Solution: open pom file and view the dependency Hierarchy [eclipse] or run
mvn dependency:tree command to find out the dependency tree and source of dependency that download the dependency. find the conflicting dependency and exclude them. For Springboot application try this.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
This is working fine for me after struggling a lots.
...
org.codehaus.mojo
cobertura-maven-plugin
2.7
test
ch.qos.logback
logback-classic
tools
com.sun
...
## I fixed with this
...
org.codehaus.mojo
cobertura-maven-plugin
2.7
test
ch.qos.logback
logback-classic
tools
com.sun
...
For me, it turned out to be an Eclipse/Maven issue after switch from log4j to logback. Take a look into your .classpath file and search for the string "log4j".
In my case I had the following there:
<classpathentry kind="var" path="M2_REPO/org/slf4j/slf4j-log4j12/1.7.1/slf4j-log4j12-1.7.1.jar"/>
<classpathentry kind="var" path="M2_REPO/log4j/log4j/1.2.17/log4j-1.2.17.jar" />
Removing those entries from the file (or you could regenerate it) fixed the issue.
For me the answer was to force a Maven rebuild. In Eclipse:
Right click on project-> Maven -> Disable Maven nature
Right click on project-> Spring Tools > Update Maven Dependencies
Right click on project-> Configure > Convert Maven Project
I solved this by going to Project Structure from my Intellij project.
I deleted the file named: Maven: org.apache.logging.log4j:log4j-to-slf4j-impl:2.14.1
This file is not shown in this picture. You may see two libraries mentioned as log4j-to-slf4j. Delete one and you are good to go.
For all those looking for the solution for spring-boot-type dependencies, the magic incantation for Gradle is this:
configurations.all {
exclude group: 'ch.qos.logback', module: 'logback-classic'
}
in your build.gradle at the top level (not inside the dependencies block).
All other solutions found in the interwebs (including the one here suggesting to exclude the slf4j module) did not work for me.
This is what I have in my build.gradle (snippet):
// Removes the annoying warning about the multiple SLF4J implementations:
// SLF4J: Class path contains multiple SLF4J bindings.
configurations.all {
exclude group: 'ch.qos.logback', module: 'logback-classic'
}
dependencies {
annotationProcessor "org.springframework.boot:spring-boot-configuration-processor"
implementation ('org.springframework.boot:spring-boot-starter-actuator')
implementation ('org.springframework.boot:spring-boot-starter-data-mongodb-reactive')
implementation ('org.springframework.boot:spring-boot-starter-webflux')
annotationProcessor "org.projectlombok:lombok:${lombokVersion}"
compileOnly "org.projectlombok:lombok:${lombokVersion}"
// Removes the annoying warning:
// warning: unknown enum constant When.MAYBE
// reason: class file for javax.annotation.meta.When not found
// See: https://stackoverflow.com/questions/29805622/could-not-find-or-load-main-class-org-gradle-wrapper-gradlewrappermain/31622432
implementation group: 'com.google.code.findbugs', name: 'jsr305', version: '3.0.2'
// other stuff...
YMMV
I had the same problem. In my pom.xml i had both
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.28</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.2.1.RELEASE</version>
</dependency>
When i deleted the spring-boot-starter-web dependency, problem was solved.
I got this issue in a non-maven project, two depended jar each contained a slf4j. I solved
by remove one depended jar, compile the project(which of course getting failure) then add the removed one back.
In case these logs are the result of this fix:
https://stackoverflow.com/a/9919375/2894819
When one of your libraries actually use it. And your application doesn't need SL4J just replace implementation to runtimeOnly.
// contains dependency to sl4j-api
implementation("com.github.doyaaaaaken:kotlin-csv-jvm:1.2.0")
// add this to remove both warnings
runtimeOnly("org.slf4j:slf4j-nop:1.7.36")
In that case when you run your app the actual dependency will be included once by the library and won't be included to the bundle of your application.jar itself.
In my case I had 2 sources of dependencies for log4 one in C:\Program Files\smcf.ear directory and the second from maven which caused the multiple binding for sl4j.
Deleting the smcf.ear directory solved the issue for me.
The combination of <scope>provided</scope> and <exclusions> didn't work for me.
I had to use this:
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<scope>system</scope>
<systemPath>${project.basedir}/empty.jar</systemPath>
</dependency>
Where empty.jar is a jar file with literally nothing in it.
Seems removing .m2 directory and :
mvn install -DskipTests -T 4 resolved this issue for me.
Related
I have finished learning Spring Boot from a tutorialspoint, my second learning path is Hibernate. They have mentioned that I need to download Hibernate package and then set CLASSPATH for it in order for its proper working.
My question is, does Spring.io contains Hibernate packages already? Or do I need to download Hibernate and set CLASSPATH manually?
You don't need to download anything by your own.
https://start.spring.io/ uses Maven or Gradle as build tool and this contains the dependency management that will download the packages for you.
When you build the application the Spring Boot plugin will create an executable JAR where all the dependencies are included.
Add this dependency to Maven
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
or this one for Gradle
implementation ("org.springframework.boot:spring-boot-starter-data-jpa")
This dependency includes JPA API, JPA Implementation, JDBC, and other needed libraries.
You can of course exclude the Hibernate dependency from the spring-boot-starter and import the dependency yourself (your preferred version) as:
For Maven:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<exclusions>
<exclusion>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.6.0.Final</version>
</dependency>
For Gradle:
implementation ("org.springframework.boot:spring-boot-starter-data-jpa") {
exclude group: "org.hibernate", module: "hibernate-core"
}
implementation "org.hibernate:hibernate-core:5.6.0.Final"
Please note that in order to use a database you must provide the Database driver, for instance, the H2 in-memory database:
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
I have a Java library built using Gradle 5.6 with some transitive dependencies suppressed
api('org.springframework.boot:spring-boot-starter-web') {
exclude module: 'spring-boot-starter-logging'
exclude module: 'spring-boot-starter-tomcat'
}
When I publish it to Maven repo I get a corresponding section of POM.xml
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<scope>compile</scope>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>*</groupId>
</exclusion>
<exclusion>
<artifactId>spring-boot-starter-logging</artifactId>
<groupId>*</groupId>
</exclusion>
</exclusions>
</dependency>
...
</dependencies>
But when I add my library as a dependency also using Gradle 5.6
dependencies {
implementation 'my.group:my.lib:1.0.0'
}
I see the excluded dependency (e.g., spring-boot-starter-tomcat) appearing in my compileClasspath configuration. Is there any way to exclude it once and for all or should I instead do it in all projects that use my library manually?
As stated in the docs (emphasis mine):
Excluding a particular transitive dependency does not guarantee that it does not show up in the dependencies of a given configuration. For example, some other dependency, which does not have any exclude rules, might pull in exactly the same transitive dependency. To guarantee that the transitive dependency is excluded from the entire configuration please use per-configuration exclude rules: Configuration.getExcludeRules(). In fact, in majority of cases the actual intention of configuring per-dependency exclusions is really excluding a dependency from the entire configuration (or classpath).
Rather then specifying an exclusion rule for each configuration, you can apply the rule to all configurations:
// Kotlin DSL
configurations.all {
exclude(mapOf("module" to "spring-boot-starter-logging"))
exclude(mapOf("module" to "spring-boot-starter-tomcat"))
}
I got Exception
java.lang.NoSuchFieldError: reportUnusedDeclaredThrownExceptionIncludeDocCommentReference outside eclipse in command line using maven.
The gwt libraries are declared at the top of list of dependencies and GWT 2.5.1 is being used.
How to solve this issue? Please help
Well, I figured out what is the problem.
In my pom.xml , I have this dependency
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>4.7.0</version>
The problem with this is that, jasper reports has a dependency on jdtcore
<dependency>
<artifactId>jdtcore</artifactId>
<groupId>eclipse</groupId>
<version>3.1.0</version>
</dependency>
jdtcore actually creates a conflict with the gwt compiler. To solve this problem, I need to add an exclusion in the jasper dependency like this
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>4.7.0</version>
<exclusions>
<exclusion>
<artifactId>jdtcore</artifactId>
<groupId>eclipse</groupId>
</exclusion>
</exclusions>
</dependency>
Now if still need the jdtcore library in the web app (normally to dynamically compile jasper reports) we can add the dependency with scope runtime like this
<dependency>
<artifactId>jdtcore</artifactId>
<groupId>eclipse</groupId>
<version>3.1.0</version>
<scope>runtime</scope>
</dependency>
Last note, if anybody gets the problem, then should look if any dependency in pom.xml has got a dependency on jdtcore, exclude it and include it as runtime
Hope this helps
For gradle exclude transitive dependency as follows in build.gradle:
dependencies {
compile('net.sf.jasperreports:jasperreports:3.7.4') {
//Exclude as it caused problems with GWT:
//http://stackoverflow.com/questions/17991063/java-lang-nosuchfielderror-reportunuseddeclaredthrownexceptionincludedoccomment
exclude group: 'eclipse', module: 'jdtcore'
}
}
Except after I made this change my jasper compilation fails. I am not sure yet how can I get Jasper compilation and GWT compilation to coexist in same project?
I have a Java Maven project whose dependencies include slf4j and its log4j adapter.
I manage the versions of log4j, slf4j-log4j12 and slf4j-api to its newest versions according to http://mvnrepository.com and especially the log4j version of 1.2.17 is well over 1.2.12 but I still get the error
SLF4J: This version of SLF4J requires log4j version 1.2.12 or later.
See also http://www.slf4j.org/codes.html#log4j_version
which is totally unclear to me.
My Maven dependency management looks like this:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.jena</groupId>
<artifactId>apache-jena-libs</artifactId>
<type>pom</type>
<version>2.10.0</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
</dependencies>
</dependencyManagement>
How can I get rid of the warning?
P.S.: I also get a java.lang.NoSuchMethodError: org.apache.log4j.Logger.isTraceEnabled().
P.P.S.: Because of your comments I remembered that the program has a "lib" folder which is not included in the classpath by Maven but by Eclipse itself so the conflicting dependencies must lie there. Sorry, I totally forgot that I guess that's my fault for mixing Maven with a lib folder. I guess I must try to convert as much of the libraries to maven dependencies.
The strange thing though is just that even if I edit "Order and Export" to put the Maven dependencies at the top, the problem still occurs.
StaticLoggerBinder code in slf4j-log4j12 which gets loaded very early on performs a check to determine whether the TRACE level is available in log4j. Here is the code:
private StaticLoggerBinder() {
loggerFactory = new Log4jLoggerFactory();
try {
Level level = Level.TRACE;
} catch (NoSuchFieldError nsfe) {
Util.report("This version of SLF4J requires log4j version 1.2.12 or later."+
" See also http://www.slf4j.org/codes.html#log4j_version");
}
}
It seems pretty airtight to me.
It may be that some other dependency is pulling in or actually embeds an earlier version of log4j. Some *-standalone.jar files are known to do that.
Check your class path at deployment time. Are you deploying in an app server? Is an older version of log4j on the server class path? In a java endorsed path?
You should define the <dependency> outside the <dependencyManagement> as the following: -
<dependencyManagement>
<dependencies>
...
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.jena</groupId>
<artifactId>apache-jena-libs</artifactId>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
</dependency>
</dependencies>
Please see Introduction to the Dependency Mechanism: Dependency Management for further information.
I hope this may help.
Changing comment to answer, since it appeared to solve the issue.
This is a classloader problem, maven built it correctly but is missing
for dependencies. Could you try to provide the missing dependencies to
maven? Otherwise I suggest you look in the Eclipse specific
dependencies.
I have a case that I have the following cyclic dependencies in maven:
JAR A version 1.1 depends on JAR B version 1.0
JAR B version 1.1 depends on JAR A version 1.0
For some reason that I don't know, Maven brings all the 4 JARs: A 1.0, A 1.1, B 1.0 and B 1.1, which results in a classpath conflict.
This really sucks. I already ask the developers of both JARs to fix this, however I can't simply sit and wait for the day that they decide to fix this.
I tried this:
<dependency>
<groupId>groupA</groupId>
<artifactId>artifactA</artifactId>
<version>1.1</version>
<type>pom</type>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>groupB</groupId>
<artifactId>artifactB</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>groupB</groupId>
<artifactId>artifactB</artifactId>
<version>1.1</version>
<type>pom</type>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>groupA</groupId>
<artifactId>artifactA</artifactId>
</exclusion>
</exclusions>
</dependency>
The result is that maven excludes all of the JARs as if none dependency were added, and the project does not compiles because there are missing classes.
So, other than just asking both JARs developers to solve this, what can I do? How can I import both the new dependencies while leaving out both the old ones?
Pragmatic solution would be to redeclare the unwanted dependencies as provided, for example:
<dependency>
<groupId>groupA</groupId>
<artifactId>artifactA</artifactId>
<version>1.0</version>
<scope>provided</scope>
</dependency>
I'm not particularly fond of using provided in such manner, since it leaves the dependency in the compile time and could lead to unwanted compile dependencies, but I see no other way in your case ;(.