classpath issue in hadoop 0.23.0 java on Ubuntu 11.10

Question

Client.java:6: package org.apache.hadoop.conf does not exist
import org.apache.hadoop.conf.Configured;
                             ^
Client.java:7: cannot find symbol
symbol  : class Tool
location: package org.apache.hadoop.util
import org.apache.hadoop.util.Tool;
                             ^
Client.java:8: cannot find symbol
symbol  : class ToolRunner
location: package org.apache.hadoop.util
import org.apache.hadoop.util.ToolRunner;
                             ^
Client.java:12: cannot find symbol
symbol: class Configured
public abstract class Client extends Configured implements Tool {
                                     ^
Client.java:12: cannot find symbol
symbol: class Tool
public abstract class Client extends Configured implements Tool {
                                                           ^
[checking Client]
[total 685ms]
5 errors

How do i need to set classpath.

I set like this :

CLASSPATH=$CLASSPATH:$HADOOP_HOME::$HADOOP_HOME/modules:$HADOOP_HOME/lib

I cannot able to run even if i mention classpath in the commandline pointing to jars directly.

score 0 · Answer 1 · answered May 08 '12 at 11:17

If you're trying to compile your code, you should look into using a build tool like Maven / Ant or just and IDE like Eclipse / Netbeans.

I would personally recommend using Maven, and a basic pom.xml would then look like this:

<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.mycompany</groupId>
    <artifactId>project-name</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
            <version>0.20.2</version>
        </dependency>
    </dependencies>
</project>

score 0 · Answer 2 · answered May 08 '12 at 11:21

Jars must be explicitly specified, or you may use a wildcard if running JDK6 +. Simply specifying a directory with jars in it is not sufficient.

Any classpath tutorial/resource would have solved this problem in less than days. This info is also included in Oracle's docs on running and compiling Java code.

classpath issue in hadoop 0.23.0 java on Ubuntu 11.10

2 Answers2