Use multiple versions of Guava in one maven project

Question

My project has the following two dependencies:

<dependency> <groupId>com.google.javascript</groupId> <artifactId>closure-compiler</artifactId> <version>v20141215</version> <exclusions> <exclusion> <groupId>com.google.protobuf</groupId> <artifactId>protobuf-java</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.apache.hadoop</groupId> <artifactId>hadoop-common</artifactId> <version>2.4.0</version> </dependency> 

As you can see in the dependency tree, they both contain a different version of Guava:

 [INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ extraction --- [INFO] +- com.google.javascript:closure-compiler:jar:v20141215:compile [INFO] | +- com.google.javascript:closure-compiler-externs:jar:v20141215:compile [INFO] | +- args4j:args4j:jar:2.0.26:compile [INFO] | +- com.google.guava:guava:jar:18.0:compile [INFO] | +- com.google.code.gson:gson:jar:2.2.4:compile [INFO] | \- com.google.code.findbugs:jsr305:jar:1.3.9:compile [INFO] +- org.apache.hadoop:hadoop-common:jar:2.4.0:compile [INFO] | +- org.apache.hadoop:hadoop-annotations:jar:2.4.0:compile [INFO] | | \- jdk.tools:jdk.tools:jar:1.7:system [INFO] | +- (com.google.guava:guava:jar:11.0.2:compile - omitted for conflict with 18.0) [INFO] | +- ... 

A well-known issue is that Guava is not backwards compatible. Therefore, I somehow need both banks.

The error - I get - the following:

 Error: tried to access method com.google.common.base.Stopwatch.<init>()V from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat 

This has already been reported: https://issues.apache.org/jira/browse/HADOOP-10961

In addition, they suggest processing it using the shading Maven plugin: https://groups.google.com/a/cloudera.org/forum/#!topic/cdh-user/d5_HqUSvVl4

What I tried here:

 <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.1</version> <configuration> <source>1.6</source> <!-- If you want to use Java 8, change this to "1.8" --> <target>1.6</target> <!-- If you want to use Java 8, change this to "1.8" --> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-shade-plugin</artifactId> <version>2.3</version> <executions> <execution> <phase>package</phase> <goals> <goal>shade</goal> </goals> <configuration> <relocations> <relocation> <pattern>com.google</pattern> <shadedPattern>project.shaded.com.google</shadedPattern> </relocation> </relocations> </configuration> </execution> </executions> </plugin> </plugins> </build> 

But I still get the same error.

Can someone help me with this Maven problem?

Thanks Felix

Answer 1

I would suggest finding the latest version of Guava that works with Hadoop 2.4, including as an explicit dependency. Then we exclude the Guava transition from the temporary compiler and Hadoop deps.

I suggest v16 because it still has a zero-args constructor in the StopWatch class: see Guava 16

Of course, this solution depends on Guava 16 working with the closure compiler.

Answer 2

Perhaps you should look into the resulting JAR and see if it is built correctly. Clearing the local maven repository may fix the problem.