Package java.net | Java In A Nutshell, 5th Edition

Package java.net

Java 1.0

The java.net package provides a powerful and flexible infrastructure for networking. This introduction describes the most commonly used classes in brief. Note that as of Java 1.4, the New I/O API of java.nio and java.nio.channels can be used for high-performance nonblocking networking. See also the javax.net.ssl package for classes for secure networking using SSL.

The URL class represents an Internet uniform resource locator (URL). It provides a very simple interface to networking: the object referred to by the URL can be downloaded with a single call, or streams may be opened to read from or write to the object. At a slightly more complex level, a URLConnection object can be obtained from a given URL object. The URLConnection class provides additional methods that allow you to work with URLs in more sophisticated ways. Java 1.4 introduced the URI class; it provides a powerful API for manipulating URI and URL strings but does not have any networking capabilities itself. Java 5.0 defines APIs for defining and registering cache, cookie, and proxy handlers to be used by built-in protocol handlers when network resources are requested through the URL class. See RequestCache , CookieHandler , ProxySelector , and Proxy .

If you want to do more than simply download an object referenced by a URL, you can do your own networking with the Socket class. This class allows you to connect to a specified port on a specified Internet host and read and write data using the InputStream and OutputStream classes of the java.io package. If you want to implement a server to accept connections from clients , you can use the related ServerSocket class. Both Socket and ServerSocket use the InetAddress address class, which represents an Internet address. Added in Java 1.4, Inet4Address and Inet6Address are subclasses that represent the addresses used by version 4 and version 6 of the IP protocol. Java 1.4 also introduced the SocketAddress class as a high-level representation of a network address that is not tied to a specific networking protocol. An IP-specific InetSocketAddress subclass encapsulates an InetAddress and a port number.

The java.net package allows you to do low-level networking with DatagramPacket objects, which may be sent and received over the network through a DatagramSocket object. MulticastSocket extends DatagramSocket to support multicast networking.

Interfaces

 public interface  ContentHandlerFactory  ; public interface  DatagramSocketImplFactory  ; public interface  FileNameMap  ; public interface  SocketImplFactory  ; public interface  SocketOptions  ; public interface  URLStreamHandlerFactory  ;

Enumerated Types

 public enum  Authenticator.RequestorType  ; public enum  Proxy.Type  ;

Classes

 public abstract class  Authenticator  ; public abstract class  CacheRequest  ; public abstract class  CacheResponse  ;    public abstract class  SecureCacheResponse  extends CacheResponse; public abstract class  ContentHandler  ; public abstract class  CookieHandler  ; public final class  DatagramPacket  ; public class  DatagramSocket  ;    public class  MulticastSocket  extends DatagramSocket; public abstract class  DatagramSocketImpl  implements SocketOptions; public class  InetAddress  implements Serializable;    public final class  Inet4Address  extends InetAddress;    public final class  Inet6Address  extends InetAddress; public final class  NetPermission  extends java.security.BasicPermission; public final class  NetworkInterface  ; public final class  PasswordAuthentication  ; public class  Proxy  ; public abstract class  ProxySelector  ; public abstract class  ResponseCache  ; public class  ServerSocket  ; public class  Socket  ; public abstract class  SocketAddress  implements Serializable;    public class  InetSocketAddress  extends SocketAddress; public abstract class  SocketImpl  implements SocketOptions; public final class  SocketPermission  extends java.security.Permission implements Serializable; public final class  URI  implements Comparable<URI>, Serializable; public final class  URL  implements Serializable; public class  URLClassLoader  extends java.security.SecureClassLoader; public abstract class  URLConnection  ;    public abstract class  HttpURLConnection  extends URLConnection;    public abstract class  JarURLConnection  extends URLConnection; public class  URLDecoder  ; public class  URLEncoder  ; public abstract class  URLStreamHandler  ;

Exceptions

 public class  HttpRetryException  extends java.io.IOException; public class  MalformedURLException  extends java.io.IOException; public class  ProtocolException  extends java.io.IOException; public class  SocketException  extends java.io.IOException;    public class  BindException  extends SocketException;    public class  ConnectException  extends SocketException;    public class  NoRouteToHostException  extends SocketException;    public class  PortUnreachableException  extends SocketException; public class  SocketTimeoutException  extends java.io.InterruptedIOException; public class  UnknownHostException  extends java.io.IOException; public class  UnknownServiceException  extends java.io.IOException; public class  URISyntaxException  extends Exception;