Java-compiler error messages usually look something like this:
src/helloworld/HelloWorld.java:21: cannot find symbol
symbol : class MessageReceiver
location: class helloworld.HelloWorld
public void helloCommand(MessageReceiver caller, String parameters)
Java is trying to tell you exactly where the error occurred and what it thinks the problem is.
The first bit of text is the name of the file where Java thinks the problem is located—in this case, the file src/helloworld/HelloWorld.java. Next is a number in between colons—that’s the line number in the file (21 here). Next is the error message itself, “cannot find symbol.” After that come the details specific to this error message, which in this ...