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2 I NHALTSVERZEICHNIS Java 2 SDK v Fortgeschrittene Programmierung 1 Spezielle Streams und Serialisierung Einführung ObjectStreams Probleme der Serialisierung ZipStreams Weitere Streams Übung Multithreading Einführung Die Klasse Thread Das Interface Runnable Prioritäten und Gruppen von Threads Synchronisation Monitore Deadlocks Datenaustausch zwischen Threads Übung Netzwerkzugriffe Grundlagen Netzwerke und Protokolle Adressierung Klassen für die Speicherung von Internetadressen Internetadressen Die Klassen URI und URL Socket-Programmierung Client-Sockets Server-Socket Chat-Verbindung Anwendungsbeispiel: Mail versenden Mail über eine Socket-Verbindung senden Mail über eine URL-Verbindung senden Das JavaMail API Übung New I/O APIs Einführung Puffermanagement Puffer ByteBuffer und Memory Mapped IO Character-Set-Codierung Channels (Kanäle) und Selectors Übung Reguläre Ausdrücke Grundlagen Mustererkennung mit regulären Ausdrücken Optionen für reguläre Ausdrücke Zeichenklassen verwenden Wiederholungen angeben Verankerung von Mustern Alternativen angeben Splitten von Zeichenfolgen Gruppieren mit Klammern Regeln für die Verwendung regulärer Ausdrücke Ersetzen von Textteilen mit regulären Ausdrücken Substitution verwenden Stückweises Ersetzen Zeichen in die Zeichenfolge einfügen Zurücksetzen des Matcher-Objekts Übung Reflection Grundlagen Die Klasse Object Die Klasse Class Das Package java.lang.reflect Methoden einer Klasse ermitteln und aufrufen Konstruktoren einer Klasse ermitteln Felder einer Klasse ermitteln und auslesen Exceptions einsetzen Dynamisches Laden von Klassen über Interfaces Beispiel für die Anwendung des Reflection-APIs Übung Logging Einführung Prinzip Einstellungen für das Logging Level Logger Handler Formatter Die Properties-Datei Standardeigenschaften ändern Logging-Konfiguration im Quellcode Logging-Konfiguration über eine eigene Properties-Datei Übung Preferences (Voreinstellungen) Einführung Voreinstellungen Hierarchische Struktur der Preferences Auf Änderungen der Preferences reagieren Preferences exportieren und importieren Übung Sicherheit Einführung Sicherheit von Java-Programmen

3 Inhaltsverzeichnis I 9.3 Klassenlader Sicherheitsmanager (SecurityManager ) Policy-Dateien (Richtliniendateien) Verschlüsselung Fingerabdruck (Message-Digest) Digitale Signaturen Authentifizierung mit Zertifikaten Übung JNI - Java Native Interface Grundlagen Aufruf nativer Funktionen Erstellen des Java-Programms Erstellen der Header-Datei Entwicklung der nativen Programmbibliothek Test der nativen Bibliothek Datentypen und Zugriff auf Strings Lokale und globale Referenzen Zugriff auf Methoden und Felder der JVM Fehlerbehandlung Invocation-API Übung Remote Method Invocation Einführung in RMI Die RMI-Architektur Besonderheiten des verteilten Objektmodells von Java Parameterübergabe bei entfernten Methoden Anwendungsfälle für RMI Entwicklung einer RMI-Anwendung Definition des Interfaces für das Remote-Objekt Entwicklung der Klasse für das Remote-Objekt Erzeugen des Stubs und des Skeletons durch den RMI-Compiler RMI-Registrierung starten Registrierung des Remote-Objekts Remote-Objekt durch Client- Anwendung aufrufen Factory-Klassen Dynamisches Laden von Klassen Security-Manager installieren Policy-Dateien Dynamisches Laden anhand eines Beispiels Remote Object Activation Entwicklung des Remote-Objekts Aufruf des Aktivierungsdienstes Registrierung des Remote-Objekts Remote-Objekt durch Client- Anwendung aufrufen Übung JDBC - Java Database Connectivity Grundlagen Beispieldatenbank installieren InterBase/FireBird als SQL Client/ Server-System Download und Installation des InterBase-Servers Start, Test und Beenden des InterBase-Servers Installation und Test des InterClients Aufbau der verwendeten Tabellen Aufbau einer Datenbankverbindung Laden des Treibers Verbindung zur Datenbank herstellen SQL-Anweisungen ausführen Einfache SQL-Anweisungen Vorbereitete SQL-Anweisungen Callable Statements und Stored Procedures Auswerten der Ergebnismengen Konfigurieren der Ergebnismenge Navigieren in der Ergebnismenge Werte der Ergebnismenge ermitteln Update der Ergebnismenge Nullwerte Auslesen von Metadaten Datenbankinformationen ermitteln Informationen über eine Ergebnismenge Transaktionen Datenbankzugriff über Applets Debuggen von JDBC-Anwendungen Übung A Anhang - Web-Server installieren A.1 Die Web-Serber Xitami, Apache A.1.1 Xitami A.1.2 Arbeiten mit Xitami A.1.3 Apache B Anhang - Datenbanken und SQL B.1 Aufbau und Funktion einer Datenbank B.1.1 Datenbankbegriffe B.2 Einführung in SQL B.2.1 Sprachumfang von SQL B.2.2 Die Datendefinitionssprache DDL B.2.3 Die Abfragesprache DQL B.2.4 Datenaktualisierung mit DML B.2.5 Der Join Stichwortverzeichnis...234

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12 3 Java 2 SDK v Fortgeschrittene Programmierung InputStream openstream() throws IOException boolean samefile(url other) giiqhw HLQH QHXH 9HUELQGXQJ ]X GHU 85/ YRQ GHU JHOHVHQ ZHUGHQ VROO XQG JLEW HLQ InputStream2EMHNW ]XU FN 9HUJOHLFKW ]ZHL 85/V LQ %H]XJ DXI GLH 85/$GUHVVH XQG JLEW true ]XU FN ZHQQ EHLGH DXI GLHVHOEH 5HVVRXUFH YHUZHLVHQ 'LH get0hwkrghq GHU.ODVVH OLHIHUQ GLH HLQ]HOQHQ %HVWDQGWHLOH GHU 85/ ]XU FN 8P HLQH 9HUELQGXQJ ]ZL VFKHQ HLQHP -DYD3URJUDPP XQG GHU 85/ HLQHV DQGHUHQ &RPSXWHUV KHU]XVWHOOHQ NDQQ GLH 0HWKRGH open- Connection JHQXW]W ZHUGHQ 6LH OLHIHUW HLQ 2EMHNW GHU DEVWUDNWHQ.ODVVH URLConnection ZHOFKHV GLHVH.RPPXQLNDWLRQVYHUELQGXQJ UHSUlVHQWLHUW 'LH 0HWKRGH openstream OLHIHUW HLQ InputStream2EMHNW GDV GD ]X YHUZHQGHW ZHUGHQ NDQQ HLQH 'DWHL DXI HLQHP DQGHUHQ DXFK DXI HLQHP ZHLW HQWIHUQWHQ 5HFKQHU ]X OHVHQ Beispiel: com\herdt\java14f\kap03\urls.java 'LHVHV %HLVSLHOSURJUDPP QXW]W GLH.ODVVH URL XP HLQH +70/6HLWH ]X OHVHQ XQG DXI GHU.RQVROH DXV]X JHEHQ $OV $UJXPHQW PXVV GHP 3URJUDPP GLH 85/ GHU +70/6HLWH DQJHJHEHQ ZHUGHQ import java.io.*; import java.net.*; public class URLs public static void main(string[] args) int l = 100; byte[] is_byte = new byte[l]; try URL url = new URL(args[0]); InputStream is = url.openstream(); System.out.println("Inhalt von " + url.getprotocol()+ "://" + url.gethost() + ": " + url.getport()); while((l = is.read(is_byte))!= -1) System.out.print(tochar(is_byte)); catch(malformedurlexception ex) System.out.println("falsche URL"); catch(ioexception ex) ex.printstacktrace(); private static char[] tochar(byte[] b) char[] c = new char[b.length]; for ( int i = 0; i < b.length; i++) c[i] = ( char)((b[i] & 0x7F) + (b[i] < 0? 128 : 0)); return c; 8P GLH.ODVVH URL ]X QXW]HQ P VVHQ 6LH GDV 3DFNDJH java.net HLQELQGHQ ) U GDV (LQOHVHQ DXV GHP InputStream ZLUG HLQ byte$uud\ EHQ WLJW 'LH DOV $UJXPHQW EHUJHEHQH 85/ ZLUG LP 2EMHNW url JHVSHLFKHUW 'LH 0HWKRGH openstream IIQHW GLH EHU GLH 85/ JHIXQGHQH 'DWHL ]XP /HVHQ

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14 3 Java 2 SDK v Fortgeschrittene Programmierung Client-Sockets (LQ Socket 2EMHNW NDQQ EHU GHQ $XIUXI HLQHV GHU IROJHQGHQ.RQVWUXNWRUHQ HU]HXJW ZHUGHQ $OOH.RQVWUXNWRUHQ N QQHQ HLQH ([FHSWLRQ YRP 7\S IOException DXVO VHQ Socket(String host, int port) Socket(String host, int port, InetAddress localaddr, int localport) Socket(InetAddress address, int port) Socket(InetAddress address, int port, InetAddress localaddr, int localport) ; $OV HUVWHU 3DUDPHWHU LVW GHU 1DPH GHV 6HUYHUV +RVWV DQ]XJHEHQ 'LHV NDQQ HLQ 6WULQJ VHLQ GHU GHQ ORJLVFKHQ 1DPHQ HQWKlOW RGHU HLQ InetAddress 2EMHNW ; 'HP.RQVWUXNWRU LVW LQ MHGHP )DOO GLH 1XPPHU GHV 3RUWV ]X EHUJHEHQ EHU GHQ GLH.RPPXQLNDWLRQ HUIROJHQ VROO 'HU 3RUW NDQQ HLQ 6WDQGDUG3RUW VHLQ ZHQQ HLQHU GHU 6WDQGDUGGLHQVWH JHQXW]W ZHUGHQ VROO ] % I U KWWS :LUG GHU 6HUYHU VHOEVW HQWZLFNHOW NDQQ GLH 3RUWQXPPHU PLW GHQ JHQDQQWHQ (LQ VFKUlQNXQJHQ VHOEVW JHZlKOW ZHUGHQ ; 'HQ EHLGHQ.RQVWUXNWRUHQ PLW YLHU 3DUDPHWHUQ N QQHQ ]XVlW]OLFK QRFK GHU 1DPH XQG GLH 3RUWQXPPHU GHV ORNDOHQ 5HFKQHUV EHUJHEHQ ZHUGHQ ; :LUG GHU DQJHJHEHQH =LHOUHFKQHU QLFKW JHIXQGHQ ZLUG HLQH ([FHSWLRQ YRP 7\S UnknownHost- Exception YRQ IOException DEJHOHLWHW DXVJHO VW 'LH.ODVVH Socket EHVLW]W HLQLJH get XQG set0hwkrghq ]XP $EIUDJHQ XQG 6HW]HQ GHU 9HUELQGXQJVHLJHQ VFKDIWHQ 'LH ZLFKWLJVWHQ 0HWKRGHQ VLQG getoutputstream XQG getinputstream ZHOFKH HLQ Output- Stream E]Z InputStream 2EMHNW ]XU FNJHEHQ :XUGH GLH 9HUELQGXQJ HUIROJUHLFK HLQJHULFKWHW NDQQ GHU 'DWHQDXVWDXVFK EHU GLHVH 2EMHNWH HUIROJHQ InetAddress getinetaddress() int getport() public OutputStream getoutputstream() throws IOException public InputStream getinputstream() throws IOException public int getsotimeout() throws SocketException public void setsotimeout(int timeout) throws SocketException /LHIHUW GLH $GUHVVH GHV +RVW5HFKQHUV ]X GHP GLH 9HU ELQGXQJ EHVWHKW ZLUG GLH 0HWKRGH YRP +RVW DXV DXI JHUXIHQ OLHIHUW VLH GLH HLJHQH $GUHVVH *LEW GLH 3RUW1XPPHU GHV +RVWV ]XU FN (U]HXJW HLQ OutputStream2EMHNW I U GDV hehuwudjhq YRQ 'DWHQ ]XP 6HUYHU *LEW HLQ InputStream2EMHNW I U GDV /HVHQ YRQ 'DWHQ YRP 6HUYHU ]XU FN /LHIHUW GLH =HLW LQ PV GLH HLQH /HVHDQIRUGHUXQJ DXI GHQ +RVW GDXHUQ GDUI EHYRU HLQH InterruptedIOException DXVJHO VW ZLUG HQWVSULFKW XQEHJUHQ]WHU :DUWH]HLW 6HW]W GLH 7LPHRXW=HLW I U GLH /HVHDQIRUGHUXQJ YRP +RVW DXI GHQ EHUJHEHQHQ :HUW LQ PV HQWVSULFKW XQEH JUHQ]WHU :DUWH]HLW Beispiel: com\herdt\java14f\kap03\client.java 'HU DEJHELOGHWH &OLHQW YHUELQGHW VLFK PLW GHP 6HUYHU XQG JLEW DXI GHP 6HUYHU GLH 1DFKULFKWHQ DXV GLH GXUFK GHQ %HQXW]HU DXI GHU.RQVROH HLQJHJHEHQ ZHUGHQ 'HP &OLHQW LVW DOV $UJXPHQW GLH $GUHVVH GHV 6HUYHUV ]X EHUJHEHQ import java.io.*; import java.net.*; public class Client public static void main(string [] args) throws IOException String s;

15 Netzwerkzugriffe 3 if(args.length!= 1) System.out.println("falscher oder fehlender Parameter\n" + "Geben Sie als Parameter die Adresse des Servers an"); System.exit(1); try Socket clientsocket = new Socket(args[0], 45678); BufferedWriter out = new BufferedWriter( new OutputStreamWriter( clientsocket.getoutputstream())); BufferedReader in = new BufferedReader( new InputStreamReader(System.in)); System.out.println("Verbindung zu " + clientsocket.getinetaddress() + " hergestellt."); do System.out.print("Nachricht an Server: "); s = in.readline(); out.write (s); out.newline(); out.flush(); while(!s.equals("ende") && clientsocket!= null); in.close(); out.close(); catch (Exception ex) ex.printstacktrace(); System.exit(1); 'DV 3DFNDJH java.io LVW I U GLH 1XW]XQJ GHU (LQ XQG $XVJDEHNODVVHQ HLQ]XELQGHQ ) U GLH $UEHLW LP 1HW]ZHUN PXVV GDV 3DFNDJH java.net HLQJHEXQGHQ ZHUGHQ 'HP &OLHQW PXVV DOV $UJXPHQW GLH $GUHVVH GHV 6HUYHUV DOV,3$GUHVVH RGHU DOV V\PEROLVFKHU 1DPH EHUJHEHQ ZHUGHQ :XUGH PHKU DOV HLQ 3DUDPHWHU RGHU NHLQ 3DUDPHWHU EHUJHEHQ ZLUG GDV 3URJUDPP PLW HLQHU )HKOHU PHOGXQJ YHUODVVHQ Notizen

16 3 Java 2 SDK v Fortgeschrittene Programmierung (V ZLUG GDV 6RFNHW2EMHNW clientsocket HU]HXJW 'LHVHV VWHOOW EHU GHQ 3RUW HLQH 9HUELQGXQJ ]XP +RVW KHU GHU DOV 3DUDPHWHU GHP 3URJUDPP EHUJHEHQ ZXUGH.DQQ GLH 9HUELQGXQJ QLFKW KHUJH VWHOOW ZHUGHQ ZLUG HLQH UnknownHostException DXVJHO VW 'DV 2EMHNW out LVW HLQ BufferedWriter GHU GDV OutputStream2EMHNW GHV clientsockets VFKDFK WHOW hehu GLHVHV 2EMHNW N QQHQ GLH 'DWHQ DQ GHQ +RVW EHUWUDJHQ ZHUGHQ 'HU BufferedReader ZLUG I U GLH ]HLOHQZHLVH %HQXW]HUHLQJDEH EHQ WLJW 'LH 0HOGXQJ HQWKlOW GLH $GUHVVH GHV +RVW5HFKQHUV GLH YRQ GHU 0HWKRGH getinetaddress JHOLHIHUW ZLUG (LQH (LQJDEH]HLOH ZLUG YRQ GHU.RQVROH JHOHVHQ XQG GHU 9DULDEOHQ s ]XJHZLHVHQ 'HU JHOHVHQH 6WULQJ ZLUG LQ GHQ $XVJDEHVWURP out GHV clientsockets JHVFKULHEHQ XQG DQ GHQ +RVW EHUWUDJHQ 'HU +RVW ZLHGHUXP PXVV EHU HLQ Socket2EMHNW HLQ InputStream2EMHNW HU]HXJHQ ZHO FKHV GLHVHQ 'DWHQVWURP OHVHQ NDQQ 'DV /HVHQ XQG 6FKUHLEHQ VROO VR ODQJH GXUFKJHI KUW ZHUGHQ ELV GLH =HLFKHQNHWWH ende HLQJHJHEHQ RGHU GLH 9HUELQGXQJ XQWHUEURFKHQ ZLUG 'DQQ ZHUGHQ EHLGH 6WUHDPV JHVFKORVVHQ 8P GLHVHV %HLVSLHO WHVWHQ ]X N QQHQ EHQ WLJHQ 6LH HLQHQ 6HUYHU GHU LP IROJHQGHQ $EVFKQLWW EHVFKULHEHQ ZLUG Server-Socket %HYRU HLQ &OLHQW GLH.RPPXQLNDWLRQ PLW HLQHP 6HUYHU DXIQHKPHQ NDQQ PXVV GHU 6HUYHU JHVWDUWHW ZHUGHQ 'HU 6HUYHU EOHLEW LQ :DUWHVWHOOXQJ ELV VLFK HLQ &OLHQW EHL LKP DQPHOGHW,Q -DYD ZLUG GLHVHU $EODXI PLWKLOIH GHU.ODVVH ServerSocket UHDOLVLHUW 'HU 6HUYHU6RFNHW NDQQ DOV *HJHQVW FN ]XP &OLHQW6RFNHW DQJHVHKHQ ZHU GHQ (U]HXJW ZLUG HLQ 6HUYHU6RFNHW EHU HLQHQ GHU IROJHQGHQ.RQVWUXNWRUHQ ServerSocket(int port) ServerSocket(int port, int backlog) ; 'HP.RQVWUXNWRU LVW GLH 3RUW1XPPHU ]X EHUJHEHQ EHU ZHOFKH GLH 9HUELQGXQJ HUIROJHQ VROO :LUG GHU :HUW 0 DQJHJHEHQ ZLUG HLQ EHOLHELJHU IUHLHU 3RUW YHUZHQGHW ; 0LW GHP ]ZHLWHQ 3DUDPHWHU NDQQ GLH PD[LPDOH /lqjh GHU :DUWHVFKODQJH EHVWLPPW ZHUGHQ :LUG HLQH 9HUELQGXQJ DQ HLQHU YROOHQ :DUWHVFKODQJH DQJHPHOGHW ZLUG GLH 9HUELQGXQJ YHUZHLJHUW 1DFK GHP (UVWHOOHQ GHV 6RFNHWV ZDUWHW GHU 6HUYHU DXI 9HUELQGXQJVDQIUDJHQ DP EHWUHIIHQGHQ 3RUW 'D]X ZLUG GLH 0HWKRGH accept DXIJHUXIHQ Socket accept() ; 'HU $XIUXI GHU 0HWKRGH accept EHZLUNW GDVV GHU 6HUYHU LQ HLQHQ :DUWH]XVWDQG EHUJHKW.RPPW HLQH 9HUELQGXQJVDQIRUGHUXQJ YRQ HLQHP &OLHQW OLHIHUW GLHVH 0HWKRGH GDV Socket2EMHNW I U GLH &OLHQW 9HUELQGXQJ 'DV ]XU FNJHJHEHQH Socket 2EMHNW NDQQ I U GLH.RPPXQLNDWLRQ PLW GHP &OLHQW6RFNHW YHUZHQGHW ZHUGHQ :LUG GLH 9HUELQGXQJ YRP &OLHQW EHHQGHW NDQQ GHU 6HUYHU HLQHQ ZHLWHUHQ &OLHQW EHGLHQHQ %HHQGHW ZHUGHQ NDQQ GHU 6HUYHU GXUFK GLH 0HWKRGH close 'LH.ODVVH EHVLW]W ZHLWHUH set XQG get0hwkrghq PLW GHQHQ,Q IRUPDWLRQHQ EHU GLH 9HUELQGXQJ DEJHIUDJW E]Z (LQVWHOOXQJHQ YRUJHQRPPHQ ZHUGHQ N QQHQ void close() InetAddress getinetaddress() int getlocalport() int getsotimeout() void setsotimeout( int timeout) 6FKOLH W GHQ 6HUYHU6RFNHW *LEW GLH ORNDOH $GUHVVH GHV 6HUYHUV ]XU FN /LHIHUW GHQ 3RUW PLW GHP GHU 6HUYHU6RFNHW YHUEXQGHQ LVW *LEW GLH =HLWVSDQQH ]XU FN I U GLH HLQ &OLHQW GHQ 6HUYHU6RFNHW EORFNLHUHQ GDUI RKQH GDVV HLQ $EEUXFK HUIROJW 7LPHRXW=HLW 6HW]W GLH 7LPHRXW=HLW DXI GHQ EHUJHEHQHQ :HUW LQ PV

17 Netzwerkzugriffe 3 Beispiel: com\herdt\java14f\kap03\server.java 'LHVHU 6HUYHU LVW GDV *HJHQVW FN ]XP ]XYRU EHVFKULHEHQHQ &OLHQW (U ZDUWHW DXI GLH 9HUELQGXQJVDQIRUGHUXQJ GHV &OLHQWV XQG JLEW GLH YRP &OLHQW JHVHQGHWHQ =HLFKHQNHWWHQ DXI GHU.RQVROH DXV :HQQ GHU &OLHQW GLH 9HU ELQGXQJ EHHQGHW ZLUG DXFK GHU 6HUYHU EHHQGHW import java.net.*; import java.io.*; import java.util.*; public class Server public static void main(string[] args) throws IOException System.out.println(">>> Server wird gestartet"); ServerSocket serversocket = new ServerSocket(45678); Socket clientsocket = serversocket.accept(); BufferedReader in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream())); System.out.println("--> Client angemeldet"); String s; try while((s = in.readline())!= null) System.out.println ("> " + s); catch(exception ex) System.out.println("<-- Client abgemeldet"); clientsocket.close();,q GHU.ODVVH Server ZLUG HLQ HLQIDFKHU 6HUYHU LPSOHPHQWLHUW 'HU 6HUYHU6RFNHW serversocket ZLUG HU]HXJW XQG NDQQ EHU GHQ 3RUW DQJHVSURFKHQ ZHUGHQ 0LW GHP $XIUXI GHU 0HWKRGH accept ZLUG GDV ServerSocket2EMHNW LQ HLQHQ :DUWH]XVWDQG YHUVHW]W (V ZDUWHW DP 3RUW ELV HLQH 9HUELQGXQJVDQIRUGHUXQJ HLQJHKW 8P GLH 'DWHQ GHV &OLHQWV OHVHQ ]X N QQHQ ZLUG GLH 0HWKRGH getinputstream DXIJHUXIHQ ZHOFKH HLQ InputStream 2EMHNW ]XU FNJLEW 'XUFK GLH 6FKDFKWHOXQJ LQ HLQHQ BufferedReader LVW GDV /HVHQ YRQ =HLFKHQNHWWHQ P JOLFK 'LH 0HWKRGH readline OLHIHUW HLQH YRP &OLHQW EHUWUDJHQH =HLOH 'LHVH ZLUG DXI GHU.RQVROH DXVJH JHEHQ :HQQ 6LH EHLVSLHOVZHLVH -%XLOGHU DOV (QWZLFNOXQJVXPJHEXQJ QXW]HQ NDQQ HV ] % XQWHU /LQX[ YRUNRPPHQ GDVV GDV =HLOHQHQGH EHL GHU 'DWHQHLQJDEH GHV &OLHQWV QLFKW HUNDQQW ZLUG 6WDUWHQ 6LH LQ GLHVHP )DOO GDV EHU VHW]WH 3URJUDPP EHU GLH.RQVROH 'HU EHVFKULHEHQH 6HUYHU LVW VHKU HLQIDFK DXIJHEDXW XQG NDQQ QXU HLQHQ &OLHQW EHGLHQHQ,Q GHQ PHLVWHQ )loohq VROOHQ PHKUHUH &OLHQWV JOHLFK]HLWLJ YRQ HLQHP 6HUYHU EHGLHQW ZHUGHQ N QQHQ 'LHV ZLUG UHDOLVLHUW LQGHP I U MH GHQ DQJHPHOGHWHQ &OLHQW HLQ QHXHU 6HUYHU7KUHDG HU]HXJW ZLUG 'HU 6HUYHU7KUHDG OHEW VR ODQJH ZLH GHU &OLHQW GLH 9HUELQGXQJ DXIUHFKWHUKlOW :LUG GLH 9HUELQGXQJ YRP &OLHQW EHHQGHW HQGHW DXFK GHU 7KUHDG Beispiel: com\herdt\java14f\kap03\server2.java,p IROJHQGHQ %HLVSLHO ZXUGH GHU ]XYRU EHVFKULHEHQH 6HUYHU HUZHLWHUW VRGDVV HU PHKUHUH &OLHQW9HUELQGXQJHQ JOHLFK]HLWLJ KHUVWHOOHQ XQG YHUZDOWHQ NDQQ

18 3 Java 2 SDK v Fortgeschrittene Programmierung import java.net.*; import java.io.*; import java.util.*; public class Server2 public static void main(string[] args) throws IOException ServerSocket serversocket = new ServerSocket(45678); int clients = 0; System.out.println(">>> Server gestartet, warte auf Client-Verbindungen"); while( true) ServerThread serverthread = new ServerThread(serverSocket.accept(), ++clients); serverthread.start(); System.out.println(">>> warte auf weitere Client-Verbindungen");,Q GHU.ODVVH Server2 LVW QXU GLH main0hwkrgh HQWKDOWHQ GLH HLQ ServerSocket2EMHNW HU]HXJW XQG DXI &OLHQW$QIRUGHUXQJHQ ZDUWHW 'LH.RPPXQLNDWLRQ PLW GHP &OLHQW ZLUG YRQ HLQHP 6HUYHU7KUHDG EHUQRPPHQ 'HU 6HUYHU6RFNHW serversocket ZLUG HU]HXJW XQG NDQQ EHU GHQ 3RUW DQJHVSURFKHQ ZHUGHQ 'DV $WWULEXW clients ]lkow GLH DQJHPHOGHWHQ &OLHQWV,Q HLQHU (QGORVVFKOHLIH ZLUG DXI &OLHQW$QIRUGHUXQJHQ PLWWHOV GHU 0HWKRGH accept JHZDUWHW 6WHOOW HLQ &OLHQW HLQH 9HUELQGXQJ KHU ZLUG HLQ QHXHU 6HUYHU7KUHDG HU]HXJW 'HP.RQVWUXNWRU GHU.ODVVH ServerThreads ZHUGHQ GDV YRQ accept JHOLHIHUWH Socket2EMHNW XQG GLH 1XPPHU GHV &OLHQWV EHU JHEHQ 'HU 6HUYHU7KUHDG I U GDV DQJHPHOGHWH 2EMHNW ZLUG JHVWDUWHW 'DQDFK JHKW GHU 6HUYHU ZLHGHU LQ GHQ :DUWH]XVWDQG EHU class ServerThread extends Thread private Socket clientsocket; private BufferedReader in; int nr; public ServerThread(Socket clientsocket, int nr) throws IOException this.clientsocket = clientsocket; this.nr = nr; in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream())); System.out.println("--> Client " + nr + "angemeldet"); public void run() String s; try while((s = in.readline())!= null) System.out.println(nr + " > " + s); System.out.println("<-- Client " + nr + " abgemeldet"); clientsocket.close(); catch (Exception ex)

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20 3 Java 2 SDK v Fortgeschrittene Programmierung (LQH YROOVWlQGLJH,PSOHPHQWDWLRQ HLQHU HLQIDFKHQ 9HUVLRQ HLQHV &KDW6HUYHUV XQG HLQHV &KDW&OLHQWV ILQGHQ 6LH LQ GHQ %HLVSLHOHQ GLHVHV.DSLWHOV &KDW6HUYHUMDYD XQG &KDW&OLHQWMDYD 3.4 Anwendungsbeispiel: Mail versenden Mail über eine Socket-Verbindung senden (LQH SUDNWLVFKH $QZHQGXQJ GHU 6RFNHW3URJUDPPLHUXQJ LVW GDV 9HUVHQGHQ YRQ (0DLOV 'D]X PXVV HLQH 9HU ELQGXQJ ]X HLQHP 0DLO6HUYHU EHU GHQ 3RUW KHUJHVWHOOW ZHUGHQ 'HU 3RUW GLHQW GHU hehuwudjxqj YRQ ( 0DLOV EHU GDV 60733URWRNROO ) U GLH hehuplwwoxqj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lIWL JHQ XQG GHQ %HWULHE I U HLQLJH =HLW ODKP OHJHQ RGHU GLH )HVWSODWWHQ I OOHQ VR JHQDQQWH 6SDP0DLOV 9LHOH NRPPHU]LHOOH 0DLO6HUYHU VLFKHUQ VLFK JHJHQ GLHVH 0DLOV DE LQGHP VLH QXU (0DLOV YRQ YHUWUDXHQVZ UGLJHQ 'RPlQHQ RGHU,3$GUHVVEHUHLFKHQ DQQHKPHQ ) U GDV 6HQGHQ HLQHU 0DLO PXVV ]XQlFKVW GLH 9HUELQGXQJ ]XP 0DLO6HUYHU KHUJHVWHOOW ZHUGHQ 'DQDFK ZLUG GLH 1DFKULFKW LP 6073)RUPDW JHVHQGHW (LQH 1DFKULFKW LP 6073)RUPDW KDW IROJHQGHQ $XIEDX HELO hostname sender MAIL FROM -adresse absender RPCT TO -adresse empfänger DATA Æ Beginn des Nachrichtenteils From: -adresse absender To: -adresse empfänger Subject: betreff Æ Leerzeile als Trennung des Headers von der Nachricht Nachricht mit beliebig vielen Zeilen. Æ Punkt als Endezeichen für die Nachricht QUIT ; 'HU QLFKW IHWW JHVFKULHEHQH 7H[W LVW GXUFK GLH HQWVSUHFKHQGHQ $QJDEHQ ]X HUVHW]HQ 'LH PLW HLQHP 3IHLO JHNHQQ]HLFKQHWHQ 7H[WH VLQG.RPPHQWDUH GLH QLFKW EHUQRPPHQ ZHUGHQ G UIHQ ;,P 1DFKULFKWHQWHLO VROOWHQ QRFKPDOV GLH $QJDEHQ ]X $EVHQGHU XQG (PSIlQJHU VRZLH GHU %HWUHII VWH KHQ 'LHVH,QIRUPDWLRQHQ ZHUGHQ LP (LQJDQJVIHQVWHU GHV 0DLO3URJUDPPV DOV $EVHQGHU XQG %HWUHII DQ JH]HLJW ; :LFKWLJ LVW HV GHQ.RSI GHV 1DFKULFKWHQWHLOV GXUFK HLQH /HHU]HLOH YRP HLJHQWOLFKHQ 1DFKULFKWHQWH[W ]X WUHQQHQ ; 'HU 3XQNW YRU GHP %HIHKO QUIT NHQQ]HLFKQHW GDV (QGH GHU 1DFKULFKW Beispiel: com\herdt\java14f\kap03\testmail.java 'LHVHV 0DLO3URJUDPP HU]HXJW DXV GHQ YRP %HQXW]HU EHU GLH.RQVROH HLQJHJHEHQHQ,QIRUPDWLRQHQ $EVHQ GHU (PSIlQJHU 0DLO6HUYHU %HWUHII XQG 7H[W HLQH (0DLO XQG YHUVFKLFNW GLHVH DQ GHQ DQJHJHEHQHQ 0DLO 6HUYHU

21 Netzwerkzugriffe 3 import java.net.*; import java.io.*; public class TestMail static PrintWriter out; static BufferedReader in; public static void main(string[] args) System.out.println("Dieses Programm verschickt Ihre "); try in = new BufferedReader(new InputStreamReader(System.in)); System.out.print("Mail von: "); String von = in.readline(); System.out.print("Mail an: "); String an = in.readline(); System.out.print("Mailserver: "); String mailserver = in.readline(); System.out.print("Betreff: "); String betreff = in.readline(); System.out.print("Nachricht: "); String nachricht = in.readline(); Socket socket = new Socket(mailServer, 25); out = new PrintWriter(socket.getOutputStream()); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); String hostname = InetAddress.getLocalHost().getHostName(); sende(null); sende("helo " + hostname); sende("mail FROM: " + von); sende("rcpt TO: " + an); sende("data"); out.println("from: " + von); out.println("to: " + an); out.println("subject: " + betreff); out.println(); out.println(nachricht); sende("."); socket.close(); catch(ioexception ex) ex.getmessage(); public static void sende(string s) throws IOException if(s!= null) System.out.println(s + "\n"); out.println(s); out.flush(); String antwort; if(antwort = in.readline())!= null) System.out.println(antwort + "\n");