CodeGuru Staff

Bruce Eckel’s Thinking in Java Contents | Prev | Next and applets The original design goal of the graphical user interface (GUI) library in Java 1.0 was to allow the programmer to build a GUI that looks good on all platforms. That goal was not achieved. Instead, the Java 1.0 Abstract Window Toolkit (AWT) produces […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next While the local copy produced by clone( ) gives the desired results in the appropriate cases, it is an example of forcing the programmer (the author of the method) to be responsible for preventing the ill effects of aliasing. What if you’re making a library that’s […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next You might suggest that, to remove clonability, the clone( ) method simply be made private, but this won’t work since you cannot take a base-class method and make it more private in a derived class. So it’s not that simple. And yet, it’s necessary to be […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next To review: all argument passing in Java is performed by passing handles. That is, when you pass “an object,” you’re really passing only a handle to an object that lives outside the method, so if you perform any modifications with that handle, you modify the […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next When you pass a handle into a method, you’re still pointing to the same object. A simple experiment demonstrates this: (See page 97 if you have trouble executing this program.) //: PassHandles.java // Passing handles around package c12;   public class PassHandles { static void […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next By this time you should be reasonably comfortable with the idea that when you’re “passing” an object, you’re actually passing a handle. In many programming languages, if not all of them, you can use that language’s “regular” way to pass objects around and most of […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next class information If you don’t know the precise type of an object, RTTI will tell you. However, there’s a limitation: the type must be known at compile time in order for you to be able to detect it using RTTI and do something useful with […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next Java performs its RTTI using the Class object, even if you’re doing something like a cast. The class Class also has a number of other ways you can use RTTI. First, you must get a handle to the appropriate Class object. One way to do […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next Consider the now familiar example of a class hierarchy that uses polymorphism. The generic type is the base class Shape, and the specific derived types are Circle, Square, and Triangle: This is a typical class hierarchy diagram, with the base class at the top and […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next The idea of run-time type identification (RTTI) seems fairly simple at first: it lets you find the exact type of an object when you have a handle to only the base type. However, the need for RTTI uncovers a whole plethora of interesting (and often […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next Java 1.1 has added an interesting feature called object serialization that allows you to take any object that implements the Serializable interface and turn it into a sequence of bytes that can later be restored fully into the original object. This is even true across […]

Bruce Eckel’s Thinking in Java Contents | Prev | Next Java 1.1 has also added some classes to support reading and writing streams in a compressed format. These are wrapped around existing IO classes to provide compression functionality. One aspect of these Java 1.1 classes stands out: They are not derived from the new Reader […]