How to Solve "Java.Lang.Noclassdeffounderror"

How can I solve java.lang.NoClassDefFoundError?

After you compile your code, you end up with .class files for each class in your program. These binary files are the bytecode that Java interprets to execute your program. The NoClassDefFoundError indicates that the classloader (in this case java.net.URLClassLoader), which is responsible for dynamically loading classes, cannot find the .class file for the class that you're trying to use.

Your code wouldn't compile if the required classes weren't present (unless classes are loaded with reflection), so usually this exception means that your classpath doesn't include the required classes. Remember that the classloader (specifically java.net.URLClassLoader) will look for classes in package a.b.c in folder a/b/c/ in each entry in your classpath. NoClassDefFoundError can also indicate that you're missing a transitive dependency of a .jar file that you've compiled against and you're trying to use.

For example, if you had a class com.example.Foo, after compiling you would have a class file Foo.class. Say for example your working directory is .../project/. That class file must be placed in .../project/com/example, and you would set your classpath to .../project/.

Side note: I would recommend taking advantage of the amazing tooling that exists for Java and JVM languages. Modern IDEs like Eclipse and IntelliJ IDEA and build management tools like Maven or Gradle will help you not have to worry about classpaths (as much) and focus on the code! That said, this link explains how to set the classpath when you execute on the command line.

Why am I getting a NoClassDefFoundError in Java?

This is caused when there is a class file that your code depends on and it is present at compile time but not found at runtime. Look for differences in your build time and runtime classpaths.

How to resolve java.lang.NoClassDefFoundError in Java

Important to Keep Some Point Regarding this Error :

1. This is caused when there is a class file that your code depends on and it is present at compile time but not found at runtime. Look for differences in your build time and runtime classpaths.
2. This exception indicates that the class was not found on the classpath. This indicates that we were trying to load the class definition, and the class did not exist on the classpath.

java.lang.NoClassDefFoundError: org/testng/IAnnotationTransformer2

Looks like version compatibility issue. Use latest version of qaf 3.1.0-RC2 with testng 7.4.0.

Updating version will fix above error, still you will see issue related to step. The reason is following steps:

@QAFTestStep(description="click on Google Search button") //missing argument placeholder 
   public void clickOnGoogleSearchButton(List<String> s) {
      System.out.printf("List: %s\n", s);
   }
           
@QAFTestStep(description="search result page should generate")//missing argument placeholder
   public void searcgResultsShouldPopulate(List<String> s) {
      System.out.printf("List: %s\n", s);
   }

If your step (method) has arguments, step description need to have argument placeholder and those arguments needs to be passed where step called. See the example below:

@QAFTestStep(description="click on Google Search button")
   public void clickOnGoogleSearchButton() {
      System.out.printf("clickOnGoogleSearchButton");
   }
           
@QAFTestStep(description="search result page should generate {results}")
   public void searcgResultsShouldPopulate(List<String> s) {
      System.out.printf("List: %s\n", s);
   }

feature file:

Feature: Text box validation

Scenario: Validate google search text box

   Given user is on google Web Page
   When user enters text 'DNA' in google search box
   And click on Google Search button
   Then search result page should generate ["a","b","c"]

Solve: java.lang.NoClassDefFoundError

If you take a look inside the directory that you downloaded, you will realize that it is an installation of cxf, not just a library. You need to actually include the jar files that come with cxf in your project, not just the cxf home directory.

Take a look at C:\Users\luyi\Downloads\apache-cxf-2.2.5\lib\WHICH_JARS, this will have instructions on which jar files you need to include in your project, depending on what you want to do in your project.

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