Package groovy.servlet

Class AbstractHttpServlet

java.lang.Object
javax.servlet.GenericServlet
javax.servlet.http.HttpServlet
groovy.servlet.AbstractHttpServlet
All Implemented Interfaces:
ResourceConnector, Serializable, Servlet, ServletConfig
Direct Known Subclasses:
GroovyServlet, TemplateServlet
public abstract class AbstractHttpServlet
extends HttpServlet
implements ResourceConnector
A base class dealing with common HTTP servlet API housekeeping aspects.

Resource name mangling (pattern replacement)

Also implements Groovy's ResourceConnector in a dynamic manner. It allows you to modify the resource name that is searched for with a replace all operation. See Pattern and Matcher for details. The servlet init parameter names are: 

 "resource.name.regex" = empty - defaults to null
 resource.name.replacement = empty - defaults to null
 resource.name.replace.all = true (default) | false means replaceFirst()
Note: If you specify a regex, you have to specify a replacement string too! Otherwise an exception gets raised.

Logging and bug-hunting options

This implementation provides a verbosity flag switching log statements. The servlet init parameter name is: 

 verbose = false(default) | true

In order to support class-loading-troubles-debugging with Tomcat 4 or higher, you can log the class loader responsible for loading some classes. See GROOVY-861 for details. The servlet init parameter name is: 

 log.GROOVY861 = false(default) | true

If you experience class-loading-troubles with Tomcat 4 (or higher) or any other servlet container using custom class loader setups, you can fallback to use (slower) reflection in Groovy's MetaClass implementation. Please contact the dev team with your problem! Thanks. The servlet init parameter name is: 

 reflection = false(default) | true
See Also:
Serialized Form

  • Field Details

  • Constructor Details

    • AbstractHttpServlet

      public AbstractHttpServlet()
      Initializes all fields with default values.

  • Method Details

    • generateNamePrefixOnce

      protected void generateNamePrefixOnce()

    • removeNamePrefix

      protected String removeNamePrefix​(String name) throws ResourceException
      Throws:
      ResourceException

    • getResourceConnection

      public URLConnection getResourceConnection​(String name) throws ResourceException
      Interface method for ResourceContainer. This is used by the GroovyScriptEngine.
      Specified by:
      getResourceConnection in interface ResourceConnector
      Throws:
      ResourceException

    • getScriptUri

      protected String getScriptUri​(HttpServletRequest request)
      Returns the include-aware uri of the script or template file.
      Parameters:
      request - the http request to analyze
      Returns:
      the include-aware uri either parsed from request attributes or hints provided by the servlet container

    • applyResourceNameMatcher

      protected String applyResourceNameMatcher​(String uri)

    • getScriptUriAsFile

      protected File getScriptUriAsFile​(HttpServletRequest request)
      Parses the http request for the real script or template source file.
      Parameters:
      request - the http request to analyze
      Returns:
      a file object using an absolute file path name, or null if the servlet container cannot translate the virtual path to a real path for any reason (such as when the content is being made available from a .war archive).

    • init

      public void init​(ServletConfig config) throws ServletException
      Overrides the generic init method to set some debug flags.
      Specified by:
      init in interface Servlet
      Overrides:
      init in class GenericServlet
      Parameters:
      config - the servlet configuration provided by the container
      Throws:
      ServletException - if init() method defined in super class javax.servlet.GenericServlet throws it

    • setVariables

      protected void setVariables​(ServletBinding binding)
      Override this method to set your variables to the Groovy binding.

      All variables bound the binding are passed to the template source text, e.g. the HTML file, when the template is merged.

      The binding provided by TemplateServlet does already include some default variables. As of this writing, they are (copied from ServletBinding):

      • "request" : HttpServletRequest
      • "response" : HttpServletResponse
      • "context" : ServletContext
      • "application" : ServletContext
      • "session" : request.getSession(false)

      And via implicit hard-coded keywords:

      • "out" : response.getWriter()
      • "sout" : response.getOutputStream()
      • "html" : new MarkupBuilder(response.getWriter())

      The binding also provides convenient methods:

      • "forward(String path)" : request.getRequestDispatcher(path).forward(request, response);
      • "include(String path)" : request.getRequestDispatcher(path).include(request, response);
      • "redirect(String location)" : response.sendRedirect(location);

      Example binding all servlet context variables: 

      
 class MyServlet extends TemplateServlet {

   protected void setVariables(ServletBinding binding) {
     // Bind a simple variable
     binding.setVariable("answer", new Long(42));

     // Bind all servlet context attributes...
     ServletContext context = (ServletContext) binding.getVariable("context");
     Enumeration enumeration = context.getAttributeNames();
     while (enumeration.hasMoreElements()) {
       String name = (String) enumeration.nextElement();
       binding.setVariable(name, context.getAttribute(name));
     }
   }
 }
      Parameters:
      binding - to be modified