MapReduce Mrunit error - hadoop

Question

I'm a new in Hadoop. Yesterday I followed the book and used JUnit as the apper unit test for meteorological data. But there were some problems.
This is my pom file:
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.9.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-hdfs</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.mrunit</groupId>
<artifactId>mrunit</artifactId>
<version>1.1.0</version>
<classifier>hadoop2</classifier>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-minicluster</artifactId>
<version>2.9.0</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
and this are problems:
java.lang.IncompatibleClassChangeError: Found class
org.apache.hadoop.mapreduce.TaskInputOutputContext, but interface was
expected
Look forward and thank you for your answer！

Answer 1

I just found out that in Hadoop 2.x, there is not Hadoop-core, so the right pom is:
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.9.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-core</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-hdfs</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.apache.mrunit</groupId>
<artifactId>mrunit</artifactId>
<version>1.1.0</version>
<classifier>hadoop2</classifier>
<scope>test</scope>
</dependency>

Answer 2

try adding different jar version.
I changed the from mrunit-1.1.0.jar to mrunit-0.9.0-incubating-hadoop2.jar
OLD JAR:-
public interface Mapper<K1, V1, K2, V2> extends JobConfigurable, Closeable { } NEW JAR:-
public class Mapper<KEYIN, VALUEIN, KEYOUT, VALUEOUT> {}
I just changed the jar from hadoop1 to hadoop2 and after that all the my unit test cases ran successfully. https://issues.apache.org/jira/browse/MRUNIT-156
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.org</groupId>
<artifactId>com.org</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<!-- JDK Tools -->
<dependency>
<groupId>jdk.tools</groupId>
<artifactId>jdk.tools</artifactId>
<scope>system</scope>
<version>1.8.0_73</version>
<systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>
</dependency>
<!-- Hadoop Core -->
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
<!-- Hadoop Mapreduce Client Core -->
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-core</artifactId>
<version>2.7.1</version>
</dependency>
<dependency>
<groupId>org.apache.mrunit</groupId>
<artifactId>mrunit</artifactId>
<version>0.9.0-incubating</version>
<classifier>hadoop1</classifier>
</dependency>
<dependency>
<groupId>org.apache.mrunit</groupId>
<artifactId>mrunit</artifactId>
<version>0.9.0-incubating</version>
<classifier>hadoop2</classifier>
</dependency>
</dependencies>
</project>