编译hadoop java文件

Question

I need to compile Java Hadoop programs.

I have compiled and got .class files for mapper and reducer.

But when I compile mainjava file, i keep getting this error.

that is it can't point mapper and reducer class files.

How can I resolve this issue?

Answer 1

You have to give all of your source files to javac

Example:

 javac -classpath /usr/local/hadoop/hadoop-core-1.0.4.jar -sourcepath src/ -d build/ MyMain.java MyMapper.java MyReducer.java

Answer 2

hadoop-core-${VERSION}.jar is in ${HADOOP_HOME}/share/common directory.

javac --classpath=${HADOOP_HOME}/share/common/hadoop-core-${HADOOP_VERSION}.jar YourClass.java

will do the work.