The network is the soul of Java. Most of what is interesting about Java centers around
the potential for dynamic, networked applications. As Java’s networking
APIs have matured, Java has also become the language of choice for implementing
traditional client-server applications and services. In this chapter, we start our
discussion of the
java.net package, which contains
the fundamental classes for communications and working with networked resources (we’ll
finish this discussion in Chapter 14). This
chapter next discusses the
java.rmi package, which
provides Java’s powerful, high-level, Remote Method Invocation (RMI) facilities.
Finally, building on the material in Chapter
12, we complete our discussion of the
package, which is highly efficient for implementing large servers.
The classes of
java.net fall into two general
categories: the Sockets API for working with low-level Internet protocols and
higher-level, web-oriented APIs that work with uniform resource locators (URLs). Figure 13-1 shows the
Java’s Sockets API provides access to the standard network protocols used for communications between hosts on the Internet. Sockets are the mechanism underlying all other kinds of portable networked communications. Sockets are the lowest-level tool—you can use sockets for any kind of communications between client and server or peer applications on the Net, but you have to implement your own application-level protocols for handling ...