Java Reflection dynamic path: ClassNotFoundException

Question

I'm trying to create an object dynamically using java reflection and when I try to execute Class.forName() it returns me the ClassNotFoundException, this is my code:

Class cls = Class.forName("foo.bar.baz.turn."+ nextStateName);

where nextStateName is the class name which I want to create. The strange thing is that if I try to do

Class cls = Class.forName("foo.bar.baz.turn.nameclass");

it works.

EDIT: this is the StackTrace

java.lang.ClassNotFoundException: foo/bar/baz/turn/IncDecValue                   
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at foo.bar.baz.turn.Turn.setDynamicState(Turn.java:83)
at foo.bar.baz.turn.ChooseDice1.receiveMove(ChooseDice1.java:47)
at foo.bar.baz.turn.turn.Turn.receiveMove(Turn.java:286)
at foo.bar.baz.turntest.ToolCard1Test.TestingCard(ToolCard1Test.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:436)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:170)
at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:166)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:113)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:58)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:112)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:55)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

EDIT*: This is a screenshot of my Maven project files using IntelliJ:

Screenshot

What am I doing wrong?

Please post the exception stack trace. – Bhesh Gurung Jun 04 '18 at 14:42 — Bhesh Gurung, Jun 04 '18 at 14:42

score 0 · Answer 1 · answered Jun 04 '18 at 15:50

In your stacktrace seem to be a lot of trailing spaces. Maybe something like this could help:

//removes spaces as seen here: https://stackoverflow.com/questions/5455794/removing-whitespace-from-strings-in-java
Class cls = Class.forName("foo.bar.baz.turn."+ (nextStateName.replaceAll("\\s+","")));

score 0 · Answer 2 · answered Jun 04 '18 at 16:21

0

Your stacktrace reads: java.lang.ClassNotFoundException: foo/bar/baz/turn/IncDecValue.

I have quickly tried to reproduce your problem and the exception which I had received has read java.lang.ClassNotFoundException: foo.bar.baz.turn.IncDecValue.

Slashes being displayed instead of dots might indicate that your classes are located in directories instead of packages. Or at least it was so when the exception has occured.

answered Jun 04 '18 at 16:21

glark

16
1

I noticed that as well, but I don't know how to fix it. If it can be useful, I added a screenshot of my project tree – Jun 04 '18 at 17:07
Maybe this link will help you? I see that you are running a JUnit5 test via IntelliJ and such situation is also mentioned here. Have you got all of the necessary JUnit5 dependencies in your pom? What about any unnecessary dependencies of previous JUnit versions? How does your test class look like? https://intellij-support.jetbrains.com/hc/en-us/community/posts/115000112530-ClassNotFoundException-trying-to-run-JUnit-5-test – glark Jun 04 '18 at 18:38
The dependencies quoted in the post you've linked me are already in my project. Also the JUnit version is only one and is the 5.1.0. Regarding my test, is a very simple test, I declare all variables that I need to call the Java Reflection method and then call it. If can be useful I can post the test code – Jun 04 '18 at 20:56

Java Reflection dynamic path: ClassNotFoundException

2 Answers2