The short answer is, that there is no way to find out the runtime type of generic type parameters in Java. I suggest reading the chapter about type erasure in the Java Tutorial for more details. A popular solution to this is to pass the Class of the type parameter into the constructor of the … Read more
There’s another solution that also works. Go to the Build Path settings in the project properties. Remove the JRE System Library Add it back; Select “Add Library” and select the JRE System Library. The default worked for me. This works because you have multiple classes in different jar files. Removing and re-adding the JRE lib … Read more
Even more meaningful : import static org.mockito.Mockito.never; import static org.mockito.Mockito.verify; // … verify(dependency, never()).someMethod(); The documentation of this feature is there ยง4 “Verifying exact number of invocations / at least x / never”, and the never javadoc is here.
Use /usr/libexec/java_home -v 1.8 command on a terminal shell to figure out where is your Java 1.8 home directory If you just want to find out the home directory of your most recent version of Java, omit the version. e.g. /usr/libexec/java_home
Since Mockito 1.9.5+ and Java 8+ You can use a lambda expression, like: when(myMock.myFunction(anyString())).thenAnswer(i -> i.getArguments()[0]); Where i is an instance of InvocationOnMock. For older versions You can create an Answer in Mockito. Let’s assume, we have an interface named MyInterface with a method myFunction. public interface MyInterface { public String myFunction(String abc); } Here … Read more
Use an enum: public enum Foo { INSTANCE; } Joshua Bloch explained this approach in his Effective Java Reloaded talk at Google I/O 2008: link to video. Also see slides 30-32 of his presentation (effective_java_reloaded.pdf): The Right Way to Implement a Serializable Singleton public enum Elvis { INSTANCE; private final String[] favoriteSongs = { “Hound … Read more
I had the same issue with WebSphere 6.1. As Ceki pointed out, there were tons of jars that WebSphere was using and one of them was pointing to an older version of slf4j. The No-Op fallback happens only with slf4j -1.6+ so anything older than that will throw an exception and halts your deployment. There … Read more
tl;dr: “PECS” is from the collection’s point of view. If you are only pulling items from a generic collection, it is a producer and you should use extends; if you are only stuffing items in, it is a consumer and you should use super. If you do both with the same collection, you shouldn’t use … Read more
This answer describes the process of retrieving the stack trace. Already have the stack trace? Read up on stack traces in “What is a stack trace, and how can I use it to debug my application errors?” The Problem Your application quit because an uncaught RuntimeException was thrown. The most common of these is the … Read more
JSP (JavaServer Pages) JSP is a Java view technology running on the server machine which allows you to write template text in client side languages (like HTML, CSS, JavaScript, ect.). JSP supports taglibs, which are backed by pieces of Java code that let you control the page flow or output dynamically. A well-known taglib is … Read more