iglu.net
Class WebHandler

java.lang.Object
  |
  +--java.lang.Thread
        |
        +--iglu.net.ClientHandler
              |
              +--iglu.net.WebHandler

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

ProxyServerExample.myURLHandler

public class WebHandler

extends ClientHandler

Implements the ClientHandler needed for a proxy server. This object lets PortServer act as a proxy server for web connections. It does all the proxy work for you. To use this object, create a descendent class and override the doneWithNetworkAccess method. In that method, put the code to deal with what should be done for a url once it has been accessed. When used with PortServer, once instance of this class will be created for every url a browser tries to access. So if an html file is accessed by a browser that has five pictures on it, at least six instances of this class will be created for that page. If using this class with the PortServer, each instance of this class will run on its own thread.

Notice that most of the members of this class get their values during processClient. So they should be set properly by doneWithNetworkAccess.

See iglu.examples.ProxyServerExample for information on how to use this class to create a proxy server.

Note: This version of WebHandler will not allow you to daisy chain onto other proxy servers. But it would not be too hard to do. Just add a new constructor which takes a host and port number of the proxy and stores them in global members. Then modify process client to not worry about any parsing. Just pass all information on to the proxy and send all the other information back.

Version:

0.5

Author:

Travis BauerTravis Bauer

Field Summary

int	ATTEMPTS The number of times to try to connect to the web server
int	BUFFSIZE
java.lang.String	clientCommands unprocessed list of chars from the client's request
java.lang.String	Command the command (GET, POST, etc) of the request
static int	defaultSize
java.lang.String	doc the page that was requested (without the server name)
java.lang.String	host host name of the web server the request was for
static int	HTML html request
int	port port for the web server the request went to
byte[]	rawServerContent unprocessed list of chars from server header
java.lang.String	requestedURL the url that was requested
java.lang.String	serverContent
java.lang.String	serverHeader
java.lang.String	serverReply
static int	UNKNOWN Not known.
int	WAIT The amount of time to pause between retries
protected java.net.Socket	webServer a socket for connecting to the webserver
protected java.io.InputStream	wsin for reading from the webServer pipe
protected java.io.OutputStream	wsout for writing to the webServer pipe

Fields inherited from class iglu.net.ClientHandler

clientSocket, in, myServer, out

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

WebHandler(java.net.Socket client, PortServer ms)
Initialize the variables for this class

Method Summary

protected java.lang.String	figureOutDestination()
static byte[]	grow(byte[] array, int size)
void	internalDoneWithNetworkAccess() Unzips the input stream if it is gzipped.
static java.lang.String	lookupValue(java.lang.String text, java.lang.String key)
protected void	performCom(java.lang.String firstLine)
void	processClient() Actually go out and get the document.
int	requestType() try to figure out what kind of request was made.

Methods inherited from class iglu.net.ClientHandler

doneWithNetworkAccess, init, run

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

webServer

protected java.net.Socket webServer

a socket for connecting to the webserver

wsin

protected java.io.InputStream wsin

for reading from the webServer pipe

wsout

protected java.io.OutputStream wsout

for writing to the webServer pipe

clientCommands

public java.lang.String clientCommands

unprocessed list of chars from the client's request

rawServerContent

public byte[] rawServerContent

unprocessed list of chars from server header

serverReply

public java.lang.String serverReply

serverHeader

public java.lang.String serverHeader

serverContent

public java.lang.String serverContent

defaultSize

public static final int defaultSize

See Also:

Constant Field Values

host

public java.lang.String host

host name of the web server the request was for

port

public int port

port for the web server the request went to

Command

public java.lang.String Command

the command (GET, POST, etc) of the request

doc

public java.lang.String doc

the page that was requested (without the server name)

requestedURL

public java.lang.String requestedURL

the url that was requested

ATTEMPTS

public int ATTEMPTS

The number of times to try to connect to the web server

WAIT

public int WAIT

The amount of time to pause between retries

BUFFSIZE

public int BUFFSIZE

UNKNOWN

public static final int UNKNOWN

Not known. This is the default type

See Also:

Constant Field Values

HTML

public static final int HTML

html request

See Also:

Constant Field Values

Constructor Detail

WebHandler

public WebHandler(java.net.Socket client,
                  PortServer ms)
           throws java.io.IOException

Initialize the variables for this class

Parameters:

client - What socket the client is listening/talking on.

ms - The portserver creating this client. Included to allow inter-client communication so it is easier to implement something like a chat server.

Throws:

java.io.IOException - If it cannot establish the correct communication.

Method Detail

processClient

public void processClient()

Actually go out and get the document. In the event that there is an error during the processing, it will print a message to the stdout, and simply return. After doneWithNetworkAccess is called, the object will close connections with the client. This will force the browser to give and "document contains no data" error, which is, of course, passed on to the user.

Overrides:

processClient in class ClientHandler

figureOutDestination

protected java.lang.String figureOutDestination()

performCom

protected void performCom(java.lang.String firstLine)

requestType

public int requestType()

try to figure out what kind of request was made.

Returns:

The requst type of this instance of the class.

internalDoneWithNetworkAccess

public void internalDoneWithNetworkAccess()

Unzips the input stream if it is gzipped. NOTE: Make sure you call super() when you override this method. Otherwise you may get garbage in the server content. In an earlier version, this code was done before the content was sent to the browser. However, the current implementation saves time since the browser does not have to wait until the zipping is done before moving on to new pages.

Overrides:

internalDoneWithNetworkAccess in class ClientHandler

lookupValue

public static java.lang.String lookupValue(java.lang.String text,
                                           java.lang.String key)

grow

public static byte[] grow(byte[] array,
                          int size)