Cannot find the Type of class to use with instanceOf

Question

I am creating an annotation where I need to match the root cause and then take action. The three classes are passed in the array as fully qualified names like javax.persistence.PersistenceException. When I use these classes in the "instanceOf" which accepts type of the class to match the rootCause, it does not work. I get an error "class0 cannot be resolved to a type". I also tried class0.getClass() to find the Type. Any advise will be appreciated.

public boolean findRootCauseOfException(Throwable throwable, String[] value) {
    Objects.requireNonNull(throwable);
    Throwable rootCause = throwable;

Object class0 = null;
Object class1 = null;
Object class2 = null;

try {
    class0 = Class.forName(value[0]);
    class1 = Class.forName(value[1]);
    class2 = Class.forName(value[2]);
} catch (ClassNotFoundException e) {
    e.printStackTrace();
}
while (rootCause != null) {
    if (rootCause instanceof class0 
            || rootCause instanceof class1 
            || rootCause instanceof class2 ) {
        return true;    
    }
    rootCause = rootCause.getCause();
}
return false;

}

Answer 1

instanceof only works with literal classes, not with Class objects.

Class.isInstance

You must call the isInstance method on Class class. Do not confuse with instanceOf.

 class0.isInstance(rootCause)