Cascading examples failed to compile?

Question

In shell I typed gradle cleanJar in the Impatient/part1 directory. The output is below. The error is "class file for org.apache.hadoop.mapred.JobConf not found". Why did it fail to compile?

:clean UP-TO-DATE
:compileJava
Download http://conjars.org/repo/cascading/cascading-core/2.0.1/cascading-core-2.0.1.pom
Download http://conjars.org/repo/cascading/cascading-hadoop/2.0.1/cascading-hadoop-2.0.1.pom
Download http://conjars.org/repo/riffle/riffle/0.1-dev/riffle-0.1-dev.pom
Download http://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.6.1/slf4j-api-1.6.1.pom
Download http://repo1.maven.org/maven2/org/slf4j/slf4j-parent/1.6.1/slf4j-parent-1.6.1.pom
Download http://repo1.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.pom
Download http://conjars.org/repo/thirdparty/jgrapht-jdk1.6/0.8.1/jgrapht-jdk1.6-0.8.1.pom
Download http://repo1.maven.org/maven2/org/codehaus/janino/janino/2.5.16/janino-2.5.16.pom
Download http://conjars.org/repo/cascading/cascading-core/2.0.1/cascading-core-2.0.1.jar
Download http://conjars.org/repo/cascading/cascading-hadoop/2.0.1/cascading-hadoop-2.0.1.jar
Download http://conjars.org/repo/riffle/riffle/0.1-dev/riffle-0.1-dev.jar
Download http://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.6.1/slf4j-api-1.6.1.jar
Download http://repo1.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.jar
Download http://conjars.org/repo/thirdparty/jgrapht-jdk1.6/0.8.1/jgrapht-jdk1.6-0.8.1.jar
Download http://repo1.maven.org/maven2/org/codehaus/janino/janino/2.5.16/janino-2.5.16.jar
/home/is_admin/lab/cascading/Impatient/part1/src/main/java/impatient/Main.java:50: error: cannot access JobConf
    Tap inTap = new Hfs( new TextDelimited( true, "\t" ), inPath );
                ^
  class file for org.apache.hadoop.mapred.JobConf not found
1 error
:compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 22.599 secs

Answer 1

try using Java 6 , gradle has some known issues with java 7

Answer 2

Add hadoop-core-1.x.y.jar from hadoop distribution to path.

This worked for me in CoPA example. I added to eclipse build path.

Add this to gradle dependencies{} section

compile( group: 'org.apache.hadoop', name: 'hadoop-core', version: '1.2.0' )