Answer:
Answer: Make sure that the language level of your IDE is set to Java 7/6/5. Some IDEs which we won't name (such as Eclipse) tend to be a version or two behind.
Answer: Unfortunately no. There are numerous revisions in all chapters, so it isn't just a matter of giving out the new chapters for free. We looked at offering a rebate if you turn in your old copy to the bookstore, but the bookstores balked at that.
Answer: Under Windows, select the MS-DOS or Command Prompt application from the start menu. There are many tutorials on the net—you may want to search Google to find one that you like.
On Mac OS X, run the Terminal application.
Answer: It is the path and/or class path.
Do the following. First, deactivate any Java installation that you may have. That is, temporarily remove the JDK you downloaded yesterday, the beta test of the nifty new environment that your brother in law gave you, etc. Install the JDK from the Oracle web site. Download the Core Java files from this web site. Set the path and remove any class path settings. Reboot. Double-check that the class path is either unset or contains the current directory (.). Keep trying. This stuff always works out eventually.
I have had to deal with hundreds of users who swore that they did everything right, except they sheepishly admitted a couple of emails later that they didn't pay attention to capitalization, thought that there was no essential difference between a ; and a :, thought it was ok to add a few spaces to "improve" on the looks of the class path, didn't want to go through the trouble of deactivating their old version of Java, or whatever. Please: If the Java interpreter can't find some or all of the classes, check your path and class path, and don't report it as an error. Thanks!
Answer: This can happen if you have a class path but you forget to add the current directory(.) into it. This is because system classes (the ones in rt.jar) are always part of the class path. The current directory is also automatically searched if no explicit class path is provided. However, if an explicit class path is provided, the current directory is automatically searched by javac but not by java.
Answer: You need to install and activate the Java Plug-in to run Java applets in your browser. Admittedly, this installation has never been easy and has been getting harder because browser makers have mistrusted Java, sometimes for good reason when Oracle dragged its feet on closing security loopholes. If you care about applets, be persistent. The installer for the JDK is supposed to install the plug-in for the default browser, but you may still need to activate Java in the browser.
Answer: The RMI setup is complex and it is very easy to get some detail wrong. Also, remember to always erase unneeded class files and to restart the naming service whenever you make a change in the configuration. Keep trying--it'll work eventually.