Resource files not found when running JUnit test - java

I'm having trouble running my JUnit test, it fails because it is not able to find the projects resources.
My test starts a server which loads all the needed resources using an URLClassLoader. I have no problem with the resources not being found when running my project otherwise. This problem only occurs when I try to run my JUnit test.
I have tried adding the file paths as arguments in my runtime configuration for the test like this, ex:
-cp .:/path/to/the/config/file
But it makes no difference.
Help please!
Project structure:

Default Maven test path is src/test/java, so if your tests are not in that directory, you have to define your test path in pom.xml with tag <testSourceDirectory>, inside <build>. You have to include maven-surefire-plugin, too.

The convention in Maven is to have all Java test code in src/test/java. This is to prevent accidental inclusion of test code in the final product. So I suggest you move your tests.
Since you don't show the code which you use to load the resource, I can't tell you whether there are any bugs in that. But /path/to/the/config/file is most likely wrong; is must be /path/to/the/config so you can say in Java getClass().getClassLoader().getResource("file").
But I suggest to use a command line argument to specify the config file:
main(String[] args) {
File configFile = new File(args[0]).getAbsoluteFile();
if(!configFile.exists()) throw new IllegalArgumentException("Unable to find config file: " + configFile);
...
}
That makes error handling much more simple. Also, it allows to use different config files in tests and later in production.

Related

Java not processing JUnit jar

I am unable to compile tests with JUnit. When I attempt to do so, I get this error:
package org.junit.jupiter.api does not exist
I get this error compiling the tests even if I put the .jar in the same directory and compile as follows:
javac -cp junit4-4.12.jar Tests.java
The contents of Test.java are:
import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.Test;
public class Tests {
... several tests ...
It's not clear to me what the issue is, and as far as I can tell, it should work with the .jar -- it's the one from /usr/share/java, where it was installed when I installed junit.
As #DwB has already mentioned you have wrong junit version.
Here is what is jupiter in JUnit: http://junit.org/junit5/docs/current/user-guide/#overview-what-is-junit-5
In simple words JUnit Jupiter API is a set of new classes which were written and introduced in junit 5 version only. And ur trying to use 4 version.
And also i want to clarify some points.
even if I put the .jar in the same directory and compile as follows
It does not matter actually is your file in the same directory or not. Its all about it's path. If you are setting jar only by name of jar file (as you did) then your path becomes relative to your current directory from where u execute javac command. You can just use absolute path and run this command from every directory you want.
https://docs.oracle.com/javase/8/docs/technotes/tools/windows/classpath.html (this one is for windows but for other os there are only minor changes in path writing)
If you get errors like package does not exist, classnotfound or anything similar then such kinds of errors almost always mean you have something wrong with your classpath or dependencies. In your case you simply had wrong version.
Now about finding necessary deps. In java world one of the main places for dependencies is maven central. Almost every opensource library can be found there and maven by default uses this repository to find and load dependencies (in your case these are jars) from there. Also you can use it to get necessary jars manually by simply using it's UI (https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api/5.0.0). There is download jar button.
Now if you know package or class but do not know in what dependency (jar for simplicity) it is located. In this case you can use http://grepcode.com or other resources which allow to search within available source code withit different repositories. In most cases this work. With juniper i did not manage to find smth there but in other cases this may help) Or the most simple case is just google package and in most cases it also will help to define entry point.
Now about solving ur issue. It seems that you will need as api as implentation. You will definitely need this one https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api/5.0.0 but it seems that you will need juniper-engine too. First try adding only API and then just go on adding necessary libraries according to errors. You can add multiple jars to cp (read provided class path guide from oracle).

Running a code with JUnit Test Cases

I have checked out a code from CVS and need to make changes to it. The code has 2 folders
Java
Test
The later has JUnit test cases. I'm not very familiar with JUnit but as far as my understanding is, the classes are duplicated in JUnit as class names. That's why I get the error in the test folder.
Class "xxxxx" already exists
I'm not sure how do I run this project without removing the folder test. Is there a way I can make eclipse ignore the JUnit test cases for now?
Go into the properties of the Eclipse project, open Java Build Path / Source and remove folder Test. Eclipse will then ignore the sources in that folder.
Test and normal java classes are merged together during build time, your error happens because the test classes have the exact same name as the normal classes. You should rename your test cases with some kind of prefix like Test to prevent them conflicting.
Doing things to work around the problem will only conflict later when you are changing the build platform, maybe your current build platform accepts it, but your future platform/editor may not, and then you have the real problems.

How to run Tests when developing javaagents?

I'm trying to fiddle with Foursquare's HeapAudit, and am attempting to set it up using IntelliJ IDEA. I have managed to get it to build just fine, using the dependencies from the pom.xml.
However, when I actually try to run the JUnit tests, basically all of them fail. I'm guessing this is because using HeapAudit requires the JVM to be started with it as a -javaagent, according to the github:
$ java -javaagent:heapaudit.jar MyTest
Presumably the tests would pass if I put this line in, and referenced the heapaudit.jar i downloaded/built earlier. However, it seems to me that if I make changes the the source, I'm gonna need to re-package this silly .jar file in order to see if it works.
Is there any way of running the tests with a -javaagent without going through the whole rigmarole of compile -> package-into-jar every testing cycle? Perhaps getting IntelliJ to attached the newly-compiled .class files as a -javaagent before running the tests?
1) Have a jar just with a META-INF/MANIFEST.MF
The manifest must be properly configured with Premain-Class and other attributes. The jar doesn't need any other files. Use this jar with the -javaagent. Provided that the agent classes are in the classpath, the agent will start normally.
This might fail when using maven-surefire-plugin with forkMode=never because by default the application classes are loaded in a child ClassLoader.
Works fine with Eclipse and Intellij.
If doing this, double check the manifest syntax (once I spent a long time to figure out that a package name was wrong).
2) Use ea-agent-loader
It will allow you to load the agent (any agent) in runtime (it uses VM.attach()). However the VM.attach() sometimes disrupts debugging and breakpoints might fail to trigger.
It will have the same issues with the surefire in forkMode=never
3) Load the agent in runtime.
Write your on code to load the agent in runtime. And call it from your #BeforeClass You will still need a jar (which you can generate in runtime if you want).
Just you need to call this (only once):
AgentLoader.loadAgentClass(YourAgentClass.class.getName());

Java/Eclipse: How to configure Run Configuration's Classpath for JUnit test?

I have an Eclipse project with the following directory structure:
MyProj/
src/main/java/
com.me.myproject.widgets
Widget.java
src/main/config
widget-config.xml
src/test/java
com.me.myproject.widgets
WidgetTest.java
src/test/config
widget-test-config.xml
The Widget class reads its config (XML) file in from anywhere on the classpath and uses it to configure its properties.
I am trying to just get WidgetTest's test cases (all written with JUnit) to run inside Eclipse when I right-click the file and go to Run As >> JUnit Test. I assume I'll have to actually run it as a customized Run Configuration with its own configured classpath, but I'm not sure about that as I've never done this before.
Does anybody know how I can get a custom Run Configuration to run WidgetTest.java as a JUnit test, and successfully place src/test/config/widget-test-config.xml on the classpath? Thanks in advance!
Please note, this question is not about how to read a resource from the runtime classpath, its about how to get it on Eclipse's JUnit Run Config classpath in the first place!
I was under the impression that as long as you have src/test/config/widget-test-config.xml inside what Eclipse considers to be a source folder, it should already be on the classpath.
Is src/test a source folder for Eclipse ? If it is and you still get the problem, try out the following experiment :
If you copy widget-test-config.xml to the src root can Widget class read it ?
If Yes
then it's a problem of the test folder not being on the classpath and you may wanna try adding it manually like so.
Right click WidgetTest and select Run As -> Junit Test. This should automatically create a Junit Run Configuration accessible at Run -> Run Configurations. You modify it's Classpath entry to add the project containing the .xml file like so :
If No
If, even after moving the .xml file to the src root (i.e. default package), your widget class cannot read it then there is something else wrong. In that case, it would be great if you could furnish the snippet of code in WidgetTest which is trying to read the .xml file.
Working Code
Here is a bit of working code :
public class A {
#Test
public void test() {
InputStream stream = A.class.getResourceAsStream("/SomeTextFile.txt");
System.out.println(stream != null);
stream = Test.class.getClassLoader()
.getResourceAsStream("SomeTextFile.txt");
System.out.println(stream != null);
}
}
The above works for me in a simple JAVA project and runs fine. (Running fine means getting
'true' printed on the console)
I am in the process of creating a GITHub repo for you to try out this code painlessly.
GIT Hub Repo with Test project
You should be able to import the project in this zip and see the code working. Right click on the Test class A and click Run As -> Junit Test, and you should see two true in the Console.
If your WidgetTest class is written as a JUnit test, eclipse will try to run it as a Junit test automatically. If it doesn't, you should right click on the class in the package explorer, choose Run As >> Run Configuration >> choose Junit
To run a Junit test:
in JUnit3, the class should implement TestCase and all the method names should start "test"
in JUnit4, all the methods should be preceded by a #Test annotation
To place that config file in the classpath: when setting the Run Configuration as above, go to the Arguments tab in the upper right pane and in the VM arguments specify the classpath:
-cp .:/path/to/the/config/file
However, if that file is in a package in the source directory, it should automatically be included in the classpath.

How to set up Maven to override a settings file for another when running a test?

See the following Maven generated project
target
classes
test-classes
src
main
java
scripts
resources
datasource-settings.xml
test
java
resources
datasource-settings.xml
I would like, when running a test, to use the settings found in test/resources/datasource-settings.xml instead of main/resources/datasource-settings.xml. Is it possible ? If so, what should i do to get my goal ?
Resources placed in ${basedir}/src/test/resources (the default location) will be automatically added to the class path set up by Maven for your unit tests and take precedence over resources placed in ${basedir}/src/main/resources. So what you want to do is actually just the default behavior.
If you haven't modified the resource settings in your POM, the test resources should show up in your classpath first, so a test should find that file before the main one without you needing to do anything extra. What sort of behavior are you seeing?

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