Question

I’m trying to load sample.properties from my classpath during my JUnit test execution and it can’t find the file in the class path. If I write a Java Main class I’m able to load the file just fine. I’m using the below ant task to execute my JUnit.

public class Testing {
 @BeforeClass
    public static void setUpBeforeClass() throws Exception {   
        Properties props = new Properties();
        InputStream fileIn = props_.getClass().getResourceAsStream("/sample.properties");
        **props.load(fileIn);**
    }

}

JUnit:

<path id="compile.classpath">
        <pathelement location="${build.classes.dir}"/>
    </path>
    <target name="test" depends="compile">
            <junit haltonfailure="true">
                <classpath refid="compile.classpath"/>
                <formatter type="plain" usefile="false"/>
                <test name="${test.suite}"/>
            </junit>
        </target>
        <target name="compile">
            <javac srcdir="${src.dir}" 
                   includeantruntime="false"
                   destdir="${build.classes.dir}" debug="true" debuglevel="lines,vars,source">
                <classpath refid="compile.classpath"/>
            </javac>
            <copy todir="${build.classes.dir}">
                <fileset dir="${src.dir}/resources"
                         includes="**/*.sql,**/*.properties" />
            </copy>
        </target>

Output:

[junit] Tests run: 0, Failures: 0, Errors: 1, Time elapsed: 0.104 sec
[junit] 
[junit] Testcase: com.example.tests.Testing took 0 sec
[junit]     Caused an ERROR
[junit] null
[junit] java.lang.NullPointerException
[junit]     at java.util.Properties$LineReader.readLine(Properties.java:418)
[junit]     at java.util.Properties.load0(Properties.java:337)
[junit]     at java.util.Properties.load(Properties.java:325)
[junit]     at com.example.tests.Testing.setUpBeforeClass(Testing.java:48)
[junit]

Answer 1

You need to add ${build.classes.dir} to compile.classpath.

Update: Based on communication in the comments, it turned out the classpath was not the problem. Instead the wrong class loader was used.

Class.getResourceAsStream() looks up the path of the resource based on the class loader the class was loaded by. As it turns out the Properties class was loaded by a different class loader than the Testing class, and the resource path was incorrect with relation to that class loader’s classpath. The solution was to use Testing.class.getResourceAsStream(...) instead of Properties.class.getResourceAsStream(...).