Question

在shell中，我在Impatient / part1目录中输入了gradle cleanJar。输出如下。错误是“未找到org.apache.hadoop.mapred.JobConf的类文件”。为什么不能编译？

: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

尝试使用Java 6，gradle有一些Java 7的已知问题

Answer 2

将hadoop-core-1.x.y.jar从hadoop发行版添加到路径。

这在CoPA示例中对我有用。我添加到eclipse构建路径。

将此添加到gradle依赖项{}部分

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

Answer 3

似乎找不到类，请检查构建路径条目中的库。

Answer 4

今天我在尝试Cascading for the Impatient教程时遇到了同样的问题。我已解决将以下内容添加到build.gradle部分中的dependencies：

compile 'org.apache.hadoop:hadoop-client:2.3.0'

我想使用Hadoop 2.3.0，但我想您可以选择自己的Hadoop版本。

PS ：要使用第一个hadoop-mapred包，您必须添加以下内容：

compile 'org.apache.hadoop:hadoop-mapred:0.22.0'

您可以找到Hadoop here可能需要的所有存储库。

Answer 5

谢谢Lalit，添加以下行为我做了诀窍而无需更改任何java版本..

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

或者，我甚至可以在类路径中添加hadoop-core jar并在gradle路径中提及

级联示例无法编译？

5 个答案: