Class CGIServlet.CGIEnvironment

java.lang.Object
org.apache.catalina.servlets.CGIServlet.CGIEnvironment
Enclosing class:
CGIServlet
protected class CGIServlet.CGIEnvironment extends Object
Encapsulates the CGI environment and rules to derive that environment from the servlet container and request information.
Author:
Martin T Dengler [root@martindengler.com], Amy Roh

  • 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
      Throws:
      IOException - an IO error occurred

  • Method Details

    • 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 boolean setupFromRequest(HttpServletRequest req) throws UnsupportedEncodingException
      Uses the HttpServletRequest to set most CGI variables
      Parameters:
      req - HttpServletRequest for information provided by the Servlet API
      Returns:
      true if the request was parsed without error, false if there was a problem
      Throws:
      UnsupportedEncodingException - Unknown encoding

    • 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

    • setCGIEnvironment

      protected boolean setCGIEnvironment(HttpServletRequest req) throws IOException
      Constructs the CGI environment to be supplied to the invoked CGI script; relies heavily on Servlet API methods and findCGI
      Parameters:
      req - request associated with the CGI Invocation
      Returns:
      true if environment was set OK, false if there was a problem and no environment was set
      Throws:
      IOException - an IO error occurred

    • expandCGIScript

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

    • toString

      public String toString()
      Returns important CGI environment information in a multi-line text format.
      Overrides:
      toString in class Object
      Returns:
      CGI environment info

    • getCommand

      protected String getCommand()
      Gets derived command string
      Returns:
      command string

    • getWorkingDirectory

      protected File getWorkingDirectory()
      Gets derived CGI working directory
      Returns:
      working directory

    • getEnvironment

      protected Map<String,String> getEnvironment()
      Gets derived CGI environment
      Returns:
      CGI environment

    • getParameters

      protected ArrayList<String> getParameters()
      Gets derived CGI query parameters
      Returns:
      CGI query parameters

    • 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

    • 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 ("")