//WebServer.java 用JAVA編寫Web服務器
import java.io.*;
import java.net.*;
public class WebServer
{
public static void main(String args[])
{
int i=1, PORT=8080;
ServerSocket server=null;
Socket client=null;
try
{
server=new ServerSocket(PORT);
System.out.println("Web Server is listening on port "+server.getLocalPort());
for (;;)
{
client=server.accept(); //接受客戶機的連接請求
new ConnectionThread(client,i).start();
i++;
}
}
catch (Exception e) {System.out.println(e);}
}
}
/* ConnnectionThread類完成與一個Web浏覽器的通信 */
class ConnectionThread extends Thread
{
Socket client; //連接Web浏覽器的socket字
int counter; //計數器
public ConnectionThread(Socket cl,int c)
{
client=cl;
counter=c;
}
public void run() //線程體
{
try
{
String destIP=client.getInetAddress().toString(); //客戶機IP地址
int destport=client.getPort(); //客戶機端口號
System.out.println("Connection "+counter+":connected to "+destIP+" on port "+destport+".");
PrintStream outstream=new PrintStream(client.getOutputStream());
DataInputStream instream=new DataInputStream(client.getInputStream());
String inline=instream.readLine(); //讀取Web浏覽器提交的請求信息
System.out.println("Received:"+inline);
if (getrequest(inline))
{ //如果是GET請求
String filename=getfilename(inline);
File file=new File(filename);
if (file.exists())
{ //若文件存在，則將文件送給Web浏覽器
System.out.println(filename+" requested.");
outstream.println("HTTP/1.0 200 OK");
outstream.println("MIME_version:1.0");
outstream.println("Content_Type:text/html");
int len=(int)file.length();
outstream.println("Content_Length:"+len);
outstream.println("");
sendfile(outstream,file); //發送文件
outstream.flush();
}
else
{ //文件不存在時
String msg1="<html><head><title>Not Found</title></head><body><h1>Error 404-file not found</h1></body></html>";
outstream.println("HTTP/1.0 404 no found");
outstream.println("Content_Type:text/html");
outstream.println("Content_Length:"+msg1.length()+2);
outstream.println("");
outstream.println(msg1);
outstream.flush();
}
}
//instream.close();
//outstream.close();
long m1=1; //延時
while (m1<11100000) {m1++;}
client.close();
}
catch (IOException e)
{
System.out.println("Exception:"+e);
}
}
/* 獲取請求類型是否為“GET” */
boolean getrequest(String s)
{
if (s.length()>0)
{
if (s.substring(0,3).equalsIgnoreCase("GET")) return true;
}
return false;
}
/* 獲取要訪問的文件名 */
String getfilename(String s)
{
String f=s.substring(s.indexOf(' ')+1);
f=f.substring(0,f.indexOf(' '));
try
{
if (f.charAt(0)=='/')
f=f.substring(1);
}
catch (StringIndexOutOfBoundsException e)
{
System.out.println("Exception:"+e);
}
if (f.equals("")) f="index.html";
return f;
}
/*把指定文件發送給Web浏覽器 */
void sendfile(PrintStream outs,File file)
{
try
{
DataInputStream in=new DataInputStream(new FileInputStream(file));
int len=(int)file.length();
byte buf[]=new byte[len];
in.readFully(buf);
outs.write(buf,0,len);
/*
DataOutputStream ou=new DataOutputStream(System.out);
ou.write(buf,0,len);
*/
outs.flush();
in.close();
}
catch (Exception e)
{
System.out.println("Error retrieving file.");
System.exit(1);
}
}
