cx.ath.matthew.cgi
Class CGI

java.lang.Object
  cx.ath.matthew.cgi.CGI

public abstract class CGI
extends Object

This is the main class you have to extend with your CGI program. You should implement the cgi() method.

Author:

Matthew Johnson <src@matthew.ath.cx>

Constructor Summary

CGI()

Method Summary

protected abstract void	cgi(Map POST, Map GET, Map ENV, Map COOKIES, String[] params) Override this method in your CGI program.
void	doCGI(String[] args) This method sets up all the CGI variables and calls the cgi() method, then writes out the page data.
void	flush() Flushes the output.
OutputStream	getOutputStream() This will return an OutputStream that you can write data directly to.
void	header(String variable, String value) Called by CGIs to send a header to the output
void	out(byte[] data) Called by CGIs to send byte data to the output.
void	out(String data) Called by CGIs to send a string to the output.
void	setcookie(String variable, String value) Sets a Cookie in the web browser.
void	setcookie(String variable, String value, String path, String domain, Date expires, boolean secure) Sets a Cookie in the web browser, with extended attributes.
protected void	setErrorHandler(CGIErrorHandler handler) Sets a custom exception handler.

Methods inherited from class java.lang.Object

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

Constructor Detail

CGI

public CGI()

Method Detail

header

public final void header(String variable,
                         String value)
                  throws CGIHeaderSentException

Called by CGIs to send a header to the output

Parameters:

variable - The header variable to set.

value - The value of the variable.

Throws:

CGIHeaderSentException - if the headers have already been sent.

See Also:

flush()

setcookie

public final void setcookie(String variable,
                            String value,
                            String path,
                            String domain,
                            Date expires,
                            boolean secure)
                     throws CGIHeaderSentException

Sets a Cookie in the web browser, with extended attributes. Calls header() so must be called before sending any output. A parameter will not be sent if it is null.

Parameters:

variable - The cookie variable to set.

value - The value of the variable.

path - The path that the cookie will be returned for.

domain - The domain that the cookie will be returned for.

expires - The expiry date of the cookie.

secure - Will only send the cookie over HTTPS if this is true.

Throws:

CGIHeaderSentException - if the headers have already been sent.

See Also:

flush(), header(java.lang.String, java.lang.String)

setcookie

public final void setcookie(String variable,
                            String value)
                     throws CGIHeaderSentException

Sets a Cookie in the web browser. Calls header() so must be called before sending any output.

Parameters:

variable - The cookie variable to set.

value - The value of the variable.

Throws:

CGIHeaderSentException - if the headers have already been sent.

See Also:

flush(), header(java.lang.String, java.lang.String)

out

public final void out(byte[] data)
               throws CGIInvalidContentFormatException

Called by CGIs to send byte data to the output. The data is buffered until the CGI exits, or a call of flush.

Parameters:

data - The page data.

Throws:

CGIInvalidContentFormatException - if text data has already been sent.

See Also:

flush()

out

public final void out(String data)
               throws CGIInvalidContentFormatException

Called by CGIs to send a string to the output. The data is buffered until the CGI exits, or a call of flush.

Parameters:

data - The page data.

Throws:

CGIInvalidContentFormatException - if raw data has already been sent.

See Also:

flush()

getOutputStream

public final OutputStream getOutputStream()
                                   throws IOException

This will return an OutputStream that you can write data directly to. Calling this method will cause the output to be flushed and the Headers sent. At the moment this is not buffered and will be sent directly to the client. Subsequent calls to out() will appear after data written to the output stream.

Returns:

an OutputStream

Throws:

IOException

See Also:

out(byte[])

flush

public final void flush()
                 throws IOException

Flushes the output. Note that you cannot send a header after a flush. If you want to send both text and binary data in a page you may do so either side of a flush.

Throws:

IOException

See Also:

header(java.lang.String, java.lang.String)

setErrorHandler

protected final void setErrorHandler(CGIErrorHandler handler)

Sets a custom exception handler. Gets called when an exception is thrown. The default error handler prints the error nicely in HTML and then exits gracefully.

Parameters:

handler - The new exception handler

cgi

protected abstract void cgi(Map POST,
                            Map GET,
                            Map ENV,
                            Map COOKIES,
                            String[] params)
                     throws Exception

Override this method in your CGI program.

Parameters:

POST - A Map of variable =$gt; value for the POST variables.

GET - A Map of variable =$gt; value for the GET variables.

ENV - A Map of variable =$gt; value for the Webserver environment variables.

COOKIES - A Map of variable =$gt; value for the browser-sent cookies.

params - An array of parameters passed to the CGI (GET with no variable assignments)

Throws:

Exception - You can throw anything, it will be caught by the error handler.

doCGI

public final void doCGI(String[] args)

This method sets up all the CGI variables and calls the cgi() method, then writes out the page data.