DatagramPacket(byte[] buf, int offset, int length)
DatagramPacket(byte[] buf, int offset, int length,
InetAddress address, int port)
DatagramPacket(byte[] buf, int offset, int length,
SocketAddress address)
DatagramPacket(byte[] buf, int length,
SocketAddress address)
, . .
DatagramSocket , . send(DatagramPacket pac), receive(DatagramPacket pac).
/* # 9: UDP : Sender.java */
package chapt15;
import java.io.*;
import java.net.*;
public class Sender {
public static void main(String[] args) {
try {
byte [] data = new byte [1000];
DatagramSocket s = new DatagramSocket();
InetAddress addr =
InetAddress.getLocalHost();
/* toxic.mp3 */
FileInputStream fr =
new FileInputStream(
new File("toxic.mp3"));
DatagramPacket pac;
while (fr.read(data)!= -1) {
//
pac = new DatagramPacket(data, data.length, addr, 8033);
s.send(pac); //
}
fr.close();
System. out. println(" ");
} catch (UnknownHostException e) {
//
e.printStackTrace();
} catch (SocketException e) {
//
e.printStackTrace();
} catch (FileNotFoundException e) {
//
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/* # 10: UDP: Recipient.java */
package chapt15;
import java.io.*;
import java.net.*;
public class Recipient {
public static void main(String[] args) {
File file = new File("toxic2.mp3");
System. out. println(" ...");
try { //
acceptFile (file, 8033, 1000);
} catch (IOException e) {
e.printStackTrace();
}
}
private static void acceptFile (File file, int port,
int pacSize) throws IOException {
byte data[] = new byte[pacSize];
DatagramPacket pac =
new DatagramPacket(data, data.length);
DatagramSocket s = new DatagramSocket(port);
FileOutputStream os =
new FileOutputStream(file);
try {
/* : 10
, */
s.setSoTimeout(60000);
while (true) {
s.receive(pac);
os.write(data);
os.flush();
}
} catch (SocketTimeoutException e) {
//
os.close();
System. out. println(
" , ");
}
}
}
15
|
|
|
/ :
1. .
2. , .
3. . , . .
4. .
5. . .
6. .
7. , on-line.
8. . , .
9. .
10. .
11. 21.
12. . - () . .
13. , IP .
14. . , TCP, . .
15. . , .
B
4 . , .
15
15.1.
socket, :
Socket socket = new Socket("host", 23);
1) POP3;
2) FTP;
3) TCP/IP;
4) IPX;
5) UDP.
15.2.
, URL :
String url = new String("http://bsu.iba.by");
1) Socket content = new
Socket(new URL(url)).connect();
2) Object content = new URL(url).getContent();
3) String content = new URLHttp(url).getString();
4) Object content = new
URLConnection(url).getContent();
5) String content = new
URLConnection(url).connect().
15.3.
?
1) getDocumentBase();
2) getCodeBase();
3) getURLAddress();
4) getCodeAddress();
5) getURLBase().
15.4.
:
Socket s = new Socket("bsu.iba.by", 8080);
1) IOException;
2) MalformedURLException;
3) UnknownHostException;
4) UnknownURLException;
5) UnknownPortException.
15.5.
:
Socket s = null;
ServerSocket server = new ServerSocket(8080);
s = server.accept();
PrintStream p = new PrintStream(s.getOutputStream());
p.print("!");
"!" ?
1) p.flush();
2) p.close();
3) s.flush();
4) s.close();
5) .
XML & Java
XML (Extensible Markup Language ) W3C , . XML . , (, .). .
|
|
|
XML SGML. XML ( , ), XHTML, SOAP, RSS, MathML.
XML , . -, , .. , . , namespace, XML ( RDF, microformat) (mixed content) XML , ( ).
XML. , (human-readable). , : <name>Java SE 6</name> <name/>. : <?xml version="1.0"?><book> <title>title</title></book><book/>XML- (root element document element). , . XML, HTML <HTML>.
<?xml version="1.0"?> <book><caption>C++</book></caption> , . caption. HTML . <?xml version="1.0"?> <book><author>Petrov</book>. , <author/>. HTML ,
(case-sensitive),
.. , <author>, <Author>, <AuToR> XML:
<author>Petrov</Author>
- . HTML .
, :
<book dateOfIssue=09/09/2007 title=JAVA in Belarus/>
L .
: <FORM method=POST action=index.jsp>
XML- :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE students SYSTEM "students.dtd">
<students>
<student login="mit" faculty="mmf">
<name>Mitar Alex</name>
<telephone>2456474</telephone>
<address>
<country>Belarus</country>
<city>Minsk</city>
<street>Kalinovsky 45</street>
</address>
</student>
<student login="pus" faculty="mmf">
<name>Pashkun Alex</name>
<telephone>3453789</telephone>
<address>
<country>Belarus</country>
<city>Brest</city>
|
|
|
<street>Knorina 56</street>
</address>
</student>
</students>
, XML. .
XML- , XML- (), . , <city>. , / , </city>. (content) , , () .
XML- , . , XML <? ?> , target ().
:
<?xml-stylesheet type="text/xsl" href="book.xsl"?>
, (stylesheet) book.xsl.
XML , HTML, <!-- -->. , :
<!-- <!-- --> -->
:
<book title=BLR<!-- -->/>
:
<book <!-- -->/>
XML- , XML: <, >, &.
<description>
<,>,&
</description>
() , & ;.
:
< <;
> >;
& &;
' ;
" .
, :
<description>
