Overview (Java EE 6 ) Java diamonds are forever. Q: How does Java solve the famous diamond problem (caused by multiple inheritance)? That is, you can implement multiple interfaces, that in turn can be implemented by one class. I know that Java has done it; my question is how? A: When you think about inheritance, remember that two types exist: Inheritance of implementationInheritance of interface One normally associates inheritance of implementation with multiple inheritance.
Inheritance of interface is a bit different. With inheritance of interface you inherit only the method declarations, not the implementation. When you inherit from a class in Java you get both inheritance of interface and implementation. When a Java class implements multiple interfaces you do run the risk of naming clashes. Public interface HonestClass { public boolean turnInLostMoney();}public interface DishonestClass { public boolean turnInLostMoney();} A class called Citizen can come along and implement these two interfaces at the same time without difficulty.
Java concurrency with thread gates. The thread gate pattern is an effective tool for controlling thread concurrency, but many developers are unfamiliar with it. Just as a traffic light can regulate the behavior of automobiles at an intersection, thread gates can block or allow thread progress based on given factors. Obi Ezechukwu introduces the concept of thread gates, then shows you how to implement them in a multithreaded prime-number generator. Level: Intermediate Multithreading and code concurrency were once the preserve of elite programmers, but the combination of multicore processing power, complex requirements, and the readily available javax.util.concurrent package has changed that. Today, enterprise application developers are expected to be knowledgeable about the various synchronization mechanisms and constructs available in the Java language. The level of expectation is even higher where the problems being solved require non-textbook and highly innovative concurrency constructs.
Thread gates: An overview. Designing with interfaces. One of the fundamental activities of any software system design is defining the interfaces between the components of the system. Because Java's interface construct allows you to define an abstract interface without specifying any implementation, a major activity of any Java program design is "figuring out what the interfaces are.
" This article looks at the motivation behind the Java interface and gives guidelines on how to make the most of this important part of Java. Deciphering the interface Almost two years ago, I wrote a chapter on the Java interface and asked a few friends who know C++ to review it. In this chapter, which is now part of my Java course reader Inner Java (see Resources), I presented interfaces primarily as a special kind of multiple inheritance: multiple inheritance of interface (the object-oriented concept) without multiple inheritance of implementation.
So given how often I found interfaces useful when I began working with Java, I knew something was going on.