//Title: AdvantaServer
//Version: 1.7
//Author: Stuart Lowry & Scott Palmateer
//Company: Science Applications International Corporation
//Description: Miniature web server for serving up data files.
//package saic.oaa2;
import java.net.*;
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
/**
* This program acts as a miniature web server. It supports posting of data, and subsequent retrieval via
* unique reference numbers. It runs in its own thread for easy inclusion in applications
* @author Scott Palmateer & Stuart Lowry
* @version 1.7
*
**/
public class AdvantaServer extends Thread
{
// The port on which this server listens.
int port;
// The datastore to store and retrieve data
DataStore store;
// The name of this server.
String servername = "Advantaserver";
String serverversion = "1.7";
public AdvantaServer (int portp, DataStore storep)
{
port = portp;
store = storep;
}
/**
* Send output to socket.
*
* @param theConnection a socket connection with a client
* @param resultheader result header, e.g. "HTTP/1.0 200 OK"
* @param contenttype content type e.g. "text/html"
* @param result the actual content
**/
void outputResult(Socket theConnection, String resultheader, String contenttype, String result)
{
try {
int resultlen = result.length();
String resultlenstring = Integer.toString(resultlen);
PrintWriter pw = new PrintWriter(new BufferedOutputStream(theConnection.getOutputStream(),1024),false);
pw.print(resultheader+"\r\n");
pw.print("Content-type: "+contenttype+"\r\n");
pw.print("Content-length: "+resultlenstring+"\r\n\r\n");
pw.print(result);
pw.flush();
} catch (Exception ex) {
System.err.println("advantaserver: caught exception (outputResult()): " + ex.getClass().getName());
}
}
/**
* Handle an unknown POST request
*
* @param theConnection a socket connection with a client
* @param command the offending request, neither "put" nor "get"
**/
void handleUnknownCommand(Socket theConnection, String command)
{
StringBuffer sb = new StringBuffer();
sb.append("\n");
sb.append("\n");
sb.append(""+servername+": Bad Request\n");
sb.append("\n");
sb.append("\n");
sb.append("400 Bad Request
\n");
sb.append("
\n");
sb.append("Unknown command:"+command+"
\n");
sb.append("The following commands are supported:
\n");
sb.append("\n");
sb.append("- put?data=...\n");
sb.append("
- get?ref=...\n");
sb.append("\n");
sb.append("\n");
outputResult(theConnection, "HTTP/1.0 400 Bad Request","text/html",sb.toString());
}
/**
* Handle an unknown request method. This server only handles POST and GET.
*
* @param theConnection a socket connection with a client
* @param command the offending method, neither "POST" nor "GET"
**/
void handleUnknownMethod(Socket theConnection, String method)
{
StringBuffer sb = new StringBuffer();
sb.append("\n");
sb.append("\n");
sb.append(""+servername+": Unimplemented Method\n");
sb.append("\n");
sb.append("\n");
sb.append("
501 Not Implemented
\n");
sb.append("
\n");
sb.append("Unknown method:"+method+"
\n");
sb.append("The following methods are supported:
\n");
sb.append("\n");
sb.append("- POST\n");
sb.append("
- GET\n");
sb.append("\n");
sb.append("\n");
outputResult(theConnection, "HTTP/1.0 501 Not Implemented","text/html",sb.toString());
}
/**
* Handle Reference not found.
*
* @param theConnection a socket connection with a client
* @param ref the unknown reference
**/
void handleReferenceNotFound(Socket theConnection, String ref)
{
StringBuffer sb = new StringBuffer();
sb.append("\n");
sb.append("\n");
sb.append(""+servername+": Not Found\n");
sb.append("\n");
sb.append("\n");
sb.append("
404 Not Found
\n");
sb.append("
\n");
sb.append("Cannot find reference:"+ref+"
\n");
sb.append("\n");
sb.append("\n");
outputResult(theConnection, "HTTP/1.0 404 Not Found","text/html",sb.toString());
}
/**
* Handle POST-put request
*
* @param theConnection a socket connection with a client
* @param br the reader assosciated with this connection
**/
void handlePostPut(Socket theConnection, BufferedReader br)
{
try
{
StringBuffer accum = new StringBuffer();
int contentlength = 0;
String inputline;
int c;
// Read the header information and extract the Content-length value.
while((inputline = br.readLine()) != null && inputline.length() != 0)
{
StringTokenizer st2 = new StringTokenizer(inputline,":");
String param = st2.nextToken().trim();
String value = st2.nextToken().trim();
if (param.compareTo("Content-length") == 0) { contentlength = Integer.parseInt(value);}
}
// Read in Content-length bytes.
// First, skip the "data=" part, then accumulate the actual data
for (int i=0; i<5; i++) {
c = br.read();
contentlength--;
}
while(contentlength != 0 && (c=br.read()) != 1)
{
accum.append((char)c);
contentlength--;
}
String ref = store.put(URLDecoder.decode(accum.toString()));
outputResult(theConnection, "HTTP/1.0 200 OK","text/plain", ref);
} catch (Exception ex) {
System.err.println("advantaserver: caught exception (handlePostPut()): " +
ex.getClass().getName());
}
}
/**
* Handle POST-get request
*
* @param theConnection a socket connection with a client
* @param br the reader assosciated with this connection
**/
void handlePostGet(Socket theConnection, BufferedReader br)
{
try
{
int contentlength = 0;
String inputline;
while((inputline = br.readLine()) != null && inputline.length() != 0)
{
StringTokenizer st2 = new StringTokenizer(inputline,":");
String param = st2.nextToken().trim();
String value = st2.nextToken().trim();
if (param.compareTo("Content-length") == 0) { contentlength = Integer.parseInt(value);}
}
// Collect the reference request
StringBuffer accum = new StringBuffer();
int c;
while(contentlength != 0 && (c=br.read()) != 1)
{
accum.append((char)c);
contentlength--;
}
StringTokenizer st3 = new StringTokenizer(accum.toString(), "=");
st3.nextToken();
String ref = st3.nextToken();
String val = store.get(ref);
if (val != null) {
val = URLEncoder.encode(val);
outputResult(theConnection, "HTTP/1.0 200 OK","application/x-www-form-urlencoded", val);
} else {
handleReferenceNotFound(theConnection,ref);
}
} catch (Exception ex) {
System.err.println("advantaserver: caught exception (handlePostGet()): " +
ex.getClass().getName());
}
}
/**
* Handle GET-get request
*
* @param theConnection a socket connection with a client
* @param command the offending method, neither "POST" nor "GET"
* @param br the reader assosciated with this connection
**/
void handleGetGet(Socket theConnection, String command, BufferedReader br)
{
try
{
int i = command.indexOf("=");
String ref = command.substring(i+1);
String val = store.get(ref);
if (val != null)
{
val = URLEncoder.encode(val);
outputResult(theConnection, "HTTP/1.0 200 OK","application/x-www-form-urlencoded", val);
} else {
handleReferenceNotFound(theConnection,ref);
}
} catch (Exception ex) {
System.err.println("advantaserver: caught exception (handleGetGet()): " +
ex.getClass().getName());
}
}
/**
* Main workhorse method. Run the server, handle requests.
*/
public void run()
{
try
{
ServerSocket theServer = new ServerSocket(port);
while (true)
{
Socket theConnection = theServer.accept();
BufferedReader br = new BufferedReader(new InputStreamReader(theConnection.getInputStream()));
String inputline = br.readLine();
StringTokenizer st = new StringTokenizer(inputline);
String method = st.nextToken();
String command = st.nextToken();
//handle POST
if (method.compareTo("POST") == 0)
{
if (command.compareTo("/put") == 0){
handlePostPut(theConnection,br);
} else if (command.compareTo("/get") == 0){
handlePostGet(theConnection,br);
} else {
handleUnknownCommand(theConnection,command);
}
} else if (method.compareTo("GET") == 0){
handleGetGet(theConnection,command,br);
} else {
handleUnknownMethod(theConnection,method);
}
br.close();
theConnection.close();
}
} catch (Exception ex) {
System.err.println("advantaserver: caught exception (run): "+ ex.getClass().getName());
}
}
public static void main (String args[])
{
int port = 4444;
if (args.length >1)
{
System.err.println("usage: java AdvantaServer [PORTNUM]");
System.exit(-1);
}
if (args.length == 1)
{
try
{
port = Integer.parseInt(args[0]);
} catch (Exception ex) {
System.err.println("usage: java AdvantaServer [PORTNUM]");
System.exit(-1);
}
Frame f = new Frame();
f.setLayout(new BorderLayout());
Button b = new Button("Exit AdvantaServer");
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
f.add(b, BorderLayout.NORTH);
f.pack();
f.show();
System.out.println("advantaserver: Started up on port: "+port);
String userName = System.getProperty("user.name");
DataStore store = new DataStore(userName,"/tmp");
AdvantaServer httpserver = new AdvantaServer(port,store);
httpserver.start();
}
}
}