I have downloaded from the Apache web site the Hadoop.1.1.2, the current
stable version. Then I simply used the command of:
to try to build the Hadoop core.
After the successful compilation, I used the diff tool to try to compare
the hardoop-core.jar that I just built, with the one comes with the
Hadoop-1.1.2 tar.gz from the Apache web site. I see a lot of class files
are different in my compiled JAR file and the ones from the
hadoop-1.1.2.tar.gz from the Apache Web site. Then I picked, for example,
the class: org/apache/hadoop/security/UserGroupInformation.class, and used
md5sum to make the comparison, and confirmed that the file content is
really different for two class files.
My java compiler is Sun Java build 1.6.0_45-b06.
I like to know what is the correct command to invoke ANT to compile the
java code from the Hadoop Source code.