Java Networking(I) 曾俊雄

Overview Java is a very good choice for networking programming. Client ： – Socket – Applet – Java Web Start – Java Network Launch Protocol

Overview(cont.) Server ： – ServerSocket – Servlet – JSP Client & Server ： – RMI – EJB – Soap – Web Service

Why Java Networking? Java is very suitable for network programming for the following reason ： – Richness As previously discussed, we have many java- technologies for network programming. – Simplicity Traditionally, we use Berkerly socket for network programming, it is very complex, e.x., we will show an example to connect to network ：

Why Java Networking?(cont.) family=AF_INET; connection=SOCK_STREAM; socketid=socket(family,connection,IPPROTO_TCP); struct hostent *hp; sockaddr1.sin_family=AF_INET; if(address[0]>='1' && address[0] ='0' && address[1]<='9') sockaddr1.sin_addr.s_addr=inet_addr(address); connect(socketid,(struct sockaddr *)(&sockaddr1),sizeof(sockaddr1)); With traditional socket library ： With java ： Socket socket=new Socket(address,port);

Why Java Networking?(cont.) – I/O functionality Java has great power in I/O ， and network transmitting is just an I/O operation DataInputStream BufferedInputStream FileInputStream ByteArrayInputStream ObjectInputStream Network I/O stream

Why Java Networking?(cont.) – Naming ability There is an API called JNDI which is used for searching remote objects. This is very important for distributed computing, an important issue for network programming. – Platform independence This is also very important for distributed computing, since programs written on different platforms can co-work together easily.