- Java Network Programming, 2nd Edition
- Preface
- 1. Why Networked Java?
- 2. Basic Network Concepts
- 3. Basic Web Concepts
- 4. Java I/O
- 5. Threads
- 6. Looking Up Internet Addresses
- DNS, IP Addresses, and All That
- The InetAddress Class
- Creating New InetAddress Objects
- public static InetAddress InetAddress.getByName(String hostName) throws UnknownHostException
- public static InetAddress[ ] InetAddress.getAllByName (String hostName) throws UnknownHostException
- public static InetAddress InetAddress.getLocalHost( ) throws UnknownHostException
- Security issues
- Other sources of InetAddress objects
- Getter Methods
- Object Methods
- Creating New InetAddress Objects
- Some Useful Programs
- 7. Retrieving Data with URLs
- 8. HTML in Swing
- 9. The Network Methods of java.applet.Applet
- Using java.applet.Applet to Download Data
- The ImageObserver Interface
- The MediaTracker Class
- Network Methods of java.applet.AppletContext
- 10. Sockets for Clients
- Socket Basics
- Investigating Protocols with Telnet
- The Socket Class
- The Constructors
- public Socket(String host, int port) throws UnknownHostException, IOException
- public Socket(InetAddress host, int port) throws IOException
- public Socket(String host, int port, InetAddress interface, int localPort) throws IOException
- public Socket(InetAddress host, int port, InetAddress interface, int localPort) throws IOException
- protected Socket( )
- protected Socket(SocketImpl impl)
- Getting Information About a Socket
- Closing the Socket
- The Object Methods
- Setting Socket Options
- The Constructors
- Socket Exceptions
- Examples
- 11. Sockets for Servers
- 12. Secure Sockets
- 13. UDP Datagrams and Sockets
- 14. Multicast Sockets
- What Is a Multicast Socket?
- Working with Multicast Sockets
- The Constructors
- Communicating with a Multicast Group
- public void joinGroup(InetAddress address) throws IOException
- public void leaveGroup(InetAddress address) throws IOException
- public void send(DatagramPacket packet, byte ttl) throws IOException
- public void setInterface(InetAddress address) throws SocketException
- public InetAddress getInterface( ) throws SocketException
- public void setTimeToLive(int ttl) throws IOException // Java 1.2
- public int getTimeToLive( ) throws IOException // Java 1.2
- Two Simple Examples
- 15. The URLConnection Class
- Opening URLConnections
- Reading Data from a Server
- Reading the Header
- Configuring the Connection
- Configuring the Client Request MIME Header
- Writing Data to a Server
- Content Handlers
- The Object Methods
- Security Considerations for URLConnections
- Guessing MIME Types
- HttpURLConnection
- JarURLConnection
- 16. Protocol Handlers
- What Is a Protocol Handler?
- The URLStreamHandler Class
- The Constructor
- Methods for Parsing URLs
- Protected void parseURL(URL u, String spec, int start, int limit)
- Protected String toExternalForm(URL u)
- Protected void setURL(URL u, String protocol, String host, int port, String file, String ref )
- Protected int getDefaultPort( ) // Java 1.3
- Protected InetAddress getHostAddress(URL u) // Java 1.3
- Protected boolean hostsEqual(URL u1, URL u2) // Java 1.3
- Protected boolean sameFile(URL u1, URL u2) // Java 1.3
- Protected boolean equals(URL u1, URL u2) // Java 1.3
- Protected int hashCode(URL u) // Java 1.3
- A Method for Connecting
- Writing a Protocol Handler
- More Protocol Handler Examples and Techniques
- The URLStreamHandlerFactory Interface
- 17. Content Handlers
- 18. Remote Method Invocation
- What Is Remote Method Invocation?
- Implementation
- Loading Classes at Runtime
- The java.rmi Package
- The Remote Interface
- The Naming Class
- public static String[ ] list(String url) throws RemoteException, MalformedURLException
- public static Remote lookup(String url) throws RemoteException, NotBoundException, AccessException, MalformedURLException
- public static void bind(String url, Remote object) throws RemoteException, AlreadyBoundException, MalformedURLException, AccessException
- public static void unbind(String url) throws RemoteException, NotBoundException, AlreadyBoundException, MalformedURLException, AccessException // Java 1.2
- public static void rebind(String url, Remote object) throws RemoteException, AccessException, MalformedURLException
- The RMISecurityManager Class
- Remote Exceptions
- The java.rmi.registry Package
- The java.rmi.server Package
- 19. The JavaMail API
- Index
- Colophon
The minimal set of steps needed to
retrieve data from a URL using a URLConnection
object are these:
Construct a
URLobject.Invoke the
URLobject’sopenConnection( )method to retrieve aURLConnectionobject for that URL.Invoke the
URLConnection’sgetInputStream( )method.Read from the input stream using the usual stream API.
The getInputStream( ) method returns a generic
InputStream, which lets you read and parse the
data that the server sends yourself.
public InputStream getInputStream( )
Example 15.1 uses the getInputStream( ) method to download a web page.
Example 15-1. Download a Web Page with a URLConnection
import java.net.*;
import java.io.*;
public class SourceViewer2 {
public static void main (String[] args) {
if (args.length > 0) {
try {
//Open the URLConnection for reading
URL u = new URL(args[0]);
URLConnection uc = u.openConnection( );
InputStream raw = uc.getInputStream( );
InputStream buffer = new BufferedInputStream(raw);
// chain the InputStream to a Reader
Reader r = new InputStreamReader(buffer);
int c;
while ((c = r.read( )) != -1) {
System.out.print((char) c);
}
}
catch (MalformedURLException e) {
System.err.println(args[0] + " is not a parseable URL");
}
catch (IOException e) {
System.err.println(e);
}
} // end if
} // end main
} // end SourceViewer2It is no accident that this program is almost the same as Example 15.5. The openStream( ) method
of the URL class just returns an
InputStream from its own
URLConnection object. The output is identical as
well, so I won’t repeat it here.
The differences between URL and
URLConnection aren’t apparent with just a
simple input stream as in this example. The biggest differences
between the two classes are:
URLConnectionprovides access to the MIME header associated with an HTTP 1.0 response.URLConnectionlets you configure the request parameters sent to the server.URLConnectionlets you write data to the server as well as read data from the server.
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