how to make jar file for custom Hive UDF

I tried to make my original Hive User Defined Function (Hive UDF). But it was bit difficult for me to compile java file correctly, because I was a beginner of JAVA and did not know much about JAVA compile options. For compiling JAVA file and making JAR file for Hive UDF, I implemented a shell script which is almost totally copied from here 8^)

script for compiling JAVA file and making JAR file

This code is written by sh script. If you want to use bash version, you can get source code from here

#!/bin/sh

if [ $# -ne 1 ]; then
    echo "Usage: $0 "
    exit 1
fi

CNAME=${1%.java}
JARNAME=$CNAME.jar
JARDIR=/home/yaboo/$CNAME
CLASSPATH=$(ls $HIVE_HOME/lib/hive-serde-*.jar):$(ls $HIVE_HOME/lib/hive-exec-*.jar):$(ls $HADOOP_HOME/hadoop-core-*.jar)
echo "javac -classpath $CLASSPATH -d $JARDIR/ $1 && jar -cf $JARNAME -C $JARDIR/ . && tell $1"

tell() {
    echo
    echo "$1 successfully compiled."
    echo
}

mkdir -p $JARDIR
javac -classpath $CLASSPATH -d $JARDIR/ $1 && jar -cf $JARNAME -C $JARDIR/ . && tell $1

custom UDF

Here, I show custom UDF named Lower. This code is copied from official Hive Wiki

package com.example.hive.udf;

import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;

public final class Lower extends UDF {
    public Text evaluate(final Text s) {
        if (s == null) {
            return null;
        }
        return new Text (s.toString().toLowerCase());
    }
}

Usage of script

> sh compile.sh Lower.java
Lower.java successfully compiled.
> ls Lower*
Lower.jar Lower.java Lower

Java.Junit.ExecViaCommandLine

Junitの使い方を少しお勉強。
なるほど、こうやって実行するのか。

<実行方法>
java -cp .:/opt/junit/junit-4.8.2.jar org.junit.runner.JUnitCore SampleTest

<実行結果>
JUnit version 4.8.2
..E
Time: 0.006
There was 1 failure:
1) testMinus(SampleTest)
junit.framework.AssertionFailedError: expected:<1> but was:<-1>
    at junit.framework.Assert.fail(Assert.java:47)
    at junit.framework.Assert.failNotEquals(Assert.java:283)
    at junit.framework.Assert.assertEquals(Assert.java:64)
    at junit.framework.Assert.assertEquals(Assert.java:195)
    at junit.framework.Assert.assertEquals(Assert.java:201)
    at SampleTest.testMinus(SampleTest.java:17)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at junit.framework.TestCase.runTest(TestCase.java:168)
    at junit.framework.TestCase.runBare(TestCase.java:134)
    at junit.framework.TestResult$1.protect(TestResult.java:110)
    at junit.framework.TestResult.runProtected(TestResult.java:128)
    at junit.framework.TestResult.run(TestResult.java:113)
    at junit.framework.TestCase.run(TestCase.java:124)
    at junit.framework.TestSuite.runTest(TestSuite.java:243)
    at junit.framework.TestSuite.run(TestSuite.java:238)
    at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
    at org.junit.runners.Suite.runChild(Suite.java:128)
    at org.junit.runners.Suite.runChild(Suite.java:24)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:117)
    at org.junit.runner.JUnitCore.runMain(JUnitCore.java:98)
    at org.junit.runner.JUnitCore.runMainAndExit(JUnitCore.java:53)
    at org.junit.runner.JUnitCore.main(JUnitCore.java:45)

FAILURES!!!
Tests run: 2,  Failures: 1