org.apache.catalina.servlets

Class CGIServlet.CGIEnvironment

Enclosing Class:
CGIServlet

protected class CGIServlet.CGIEnvironment
extends java.lang.Object

Encapsulates the CGI environment and rules to derive that environment from the servlet container and request information.

Version:
$Revision: 1.22.2.2 $, $Date: 2004/11/19 14:51:17 $

Author:
Martin Dengler [root@martindengler.com]

Since:
Tomcat 4.0

Constructor Summary

CGIEnvironment(HttpServletRequest req, ServletContext context)
Creates a CGIEnvironment and derives the necessary environment, query parameters, working directory, cgi command, etc.

Method Summary

protected String
blanksToString(String couldBeBlank, String subForBlanks)
Converts blank strings to another string
protected void
expandCGIScript()
Extracts requested resource from web app archive to context work directory to enable CGI script to be executed.
protected String[]
findCGI(String pathInfo, String webAppRootDir, String contextPath, String servletPath, String cgiPathPrefix)
Resolves core information about the cgi script.
protected String
getCommand()
Gets derived command string
protected Hashtable
getEnvironment()
Gets derived CGI environment
protected ArrayList
getParameters()
Gets derived CGI query parameters
protected File
getWorkingDirectory()
Gets derived CGI working directory
protected boolean
isValid()
Gets validity status
protected String
nullsToBlanks(String s)
Converts null strings to blank strings ("")
protected String
nullsToString(String couldBeNull, String subForNulls)
Converts null strings to another string
protected boolean
setCGIEnvironment(HttpServletRequest req)
Constructs the CGI environment to be supplied to the invoked CGI script; relies heavliy on Servlet API methods and findCGI
protected void
setupFromContext(ServletContext context)
Uses the ServletContext to set some CGI variables
protected void
setupFromRequest(HttpServletRequest req)
Uses the HttpServletRequest to set most CGI variables
String
toString()
Print important CGI environment information in a easy-to-read HTML table

Constructor Details

CGIEnvironment

protected CGIEnvironment(HttpServletRequest req,
                         ServletContext context)
            throws IOException
Creates a CGIEnvironment and derives the necessary environment, query parameters, working directory, cgi command, etc.

Parameters:
req - HttpServletRequest for information provided by the Servlet API
context - ServletContext for information provided by the Servlet API

Method Details

blanksToString

protected String blanksToString(String couldBeBlank,
                                String subForBlanks)
Converts blank strings to another string

Parameters:
couldBeBlank - string to be converted if necessary
subForBlanks - string to return instead of a blank string

Returns:
a non-null string, either the original or the substitute string if the original was null or empty ("")


expandCGIScript

protected void expandCGIScript()
Extracts requested resource from web app archive to context work directory to enable CGI script to be executed.


findCGI

protected String[] findCGI(String pathInfo,
                           String webAppRootDir,
                           String contextPath,
                           String servletPath,
                           String cgiPathPrefix)
Resolves core information about the cgi script.

Example URI:

 /servlet/cgigateway/dir1/realCGIscript/pathinfo1 
  • path = $CATALINA_HOME/mywebapp/dir1/realCGIscript
  • scriptName = /servlet/cgigateway/dir1/realCGIscript
  • cgiName = /dir1/realCGIscript
  • name = realCGIscript

CGI search algorithm: search the real path below <my-webapp-root> and find the first non-directory in the getPathTranslated("/"), reading/searching from left-to-right.

The CGI search path will start at webAppRootDir + File.separator + cgiPathPrefix (or webAppRootDir alone if cgiPathPrefix is null).

cgiPathPrefix is defined by setting this servlet's cgiPathPrefix init parameter

Parameters:
pathInfo - String from HttpServletRequest.getPathInfo()
webAppRootDir - String from context.getRealPath("/")
contextPath - String as from HttpServletRequest.getContextPath()
servletPath - String as from HttpServletRequest.getServletPath()
cgiPathPrefix - subdirectory of webAppRootDir below which the web app's CGIs may be stored; can be null. The CGI search path will start at webAppRootDir + File.separator + cgiPathPrefix (or webAppRootDir alone if cgiPathPrefix is null). cgiPathPrefix is defined by setting the servlet's cgiPathPrefix init parameter.

Returns:
  • path - full file-system path to valid cgi script, or null if no cgi was found
  • scriptName - CGI variable SCRIPT_NAME; the full URL path to valid cgi script or null if no cgi was found
  • cgiName - servlet pathInfo fragment corresponding to the cgi script itself, or null if not found
  • name - simple name (no directories) of the cgi script, or null if no cgi was found

Author:
Martin Dengler [root@martindengler.com]

Since:
Tomcat 4.0


getCommand

protected String getCommand()
Gets derived command string

Returns:
command string


getEnvironment

protected Hashtable getEnvironment()
Gets derived CGI environment

Returns:
CGI environment


getParameters

protected ArrayList getParameters()
Gets derived CGI query parameters

Returns:
CGI query parameters


getWorkingDirectory

protected File getWorkingDirectory()
Gets derived CGI working directory

Returns:
working directory


isValid

protected boolean isValid()
Gets validity status

Returns:
true if this environment is valid, false otherwise


nullsToBlanks

protected String nullsToBlanks(String s)
Converts null strings to blank strings ("")

Parameters:
s - string to be converted if necessary

Returns:
a non-null string, either the original or the empty string ("") if the original was null


nullsToString

protected String nullsToString(String couldBeNull,
                               String subForNulls)
Converts null strings to another string

Parameters:
couldBeNull - string to be converted if necessary
subForNulls - string to return instead of a null string

Returns:
a non-null string, either the original or the substitute string if the original was null


setCGIEnvironment

protected boolean setCGIEnvironment(HttpServletRequest req)
            throws IOException
Constructs the CGI environment to be supplied to the invoked CGI script; relies heavliy on Servlet API methods and findCGI

Parameters:
req - request associated with the CGI invokation

Returns:
true if environment was set OK, false if there was a problem and no environment was set


setupFromContext

protected void setupFromContext(ServletContext context)
Uses the ServletContext to set some CGI variables

Parameters:
context - ServletContext for information provided by the Servlet API


setupFromRequest

protected void setupFromRequest(HttpServletRequest req)
Uses the HttpServletRequest to set most CGI variables

Parameters:
req - HttpServletRequest for information provided by the Servlet API


toString

public String toString()
Print important CGI environment information in a easy-to-read HTML table

Returns:
HTML string containing CGI environment info


Copyright B) 2000-2003 Apache Software Foundation. All Rights Reserved.