Package groovy.servlet

Class AbstractHttpServlet

java.lang.Object
javax.servlet.GenericServlet
javax.servlet.http.HttpServlet
groovy.servlet.AbstractHttpServlet
All Implemented Interfaces:
ResourceConnector, java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig
Direct Known Subclasses:
GroovyServlet, TemplateServlet
public abstract class AbstractHttpServlet
extends javax.servlet.http.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 Summary

    Fields
    Modifier and Type Field Description
    static java.lang.String CONTENT_TYPE_TEXT_HTML
    Content type of the HTTP response.
    protected java.lang.String encoding
    Encoding to use, becomes charset part of contentType.
    static java.lang.String INC_PATH_INFO
    Servlet API include key name: path_info
    static java.lang.String INC_REQUEST_URI  
    static java.lang.String INC_SERVLET_PATH
    Servlet API include key name: servlet_path
    static java.lang.String INIT_PARAM_RESOURCE_NAME_REGEX  
    static java.lang.String INIT_PARAM_RESOURCE_NAME_REGEX_FLAGS  
    protected java.lang.String namePrefix
    a.fink: it was in removeNamePrefix(java.lang.String), but was extracted to var for optimization
    protected boolean reflection
    Mirrors the static value of the reflection flag in MetaClass.
    protected java.util.regex.Pattern resourceNamePattern
    Either null or a compiled pattern read from ""resource.name.regex"" and used in getScriptUri(HttpServletRequest).
    protected boolean resourceNameReplaceAll
    The replace method to use on the matcher.
    protected java.lang.String resourceNameReplacement
    The replacement used by the resource name matcher.
    protected javax.servlet.ServletContext servletContext
    Servlet (or the web application) context.
    protected boolean verbose
    Controls almost all log output.

  • Constructor Summary

    Constructors
    Constructor Description
    AbstractHttpServlet()
    Initializes all fields with default values.

  • Method Summary

    Modifier and Type Method Description
    protected java.lang.String applyResourceNameMatcher​(java.lang.String uri)  
    protected void generateNamePrefixOnce()  
    java.net.URLConnection getResourceConnection​(java.lang.String name)
    Interface method for ResourceContainer.
    protected java.lang.String getScriptUri​(javax.servlet.http.HttpServletRequest request)
    Returns the include-aware uri of the script or template file.
    protected java.io.File getScriptUriAsFile​(javax.servlet.http.HttpServletRequest request)
    Parses the http request for the real script or template source file.
    void init​(javax.servlet.ServletConfig config)
    Overrides the generic init method to set some debug flags.
    protected java.lang.String removeNamePrefix​(java.lang.String name)  
    protected void setVariables​(ServletBinding binding)
    Override this method to set your variables to the Groovy binding.

    Methods inherited from class javax.servlet.http.HttpServlet

    doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

    Methods inherited from class javax.servlet.GenericServlet

    destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

    Methods inherited from class java.lang.Object

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

  • Field Details

    • INIT_PARAM_RESOURCE_NAME_REGEX

      public static final java.lang.String INIT_PARAM_RESOURCE_NAME_REGEX
      See Also:
      Constant Field Values

    • INIT_PARAM_RESOURCE_NAME_REGEX_FLAGS

      public static final java.lang.String INIT_PARAM_RESOURCE_NAME_REGEX_FLAGS
      See Also:
      Constant Field Values

    • CONTENT_TYPE_TEXT_HTML

      public static final java.lang.String CONTENT_TYPE_TEXT_HTML
      Content type of the HTTP response.
      See Also:
      Constant Field Values

    • INC_PATH_INFO

      public static final java.lang.String INC_PATH_INFO
      Servlet API include key name: path_info
      See Also:
      Constant Field Values

    • INC_REQUEST_URI

      public static final java.lang.String INC_REQUEST_URI
      See Also:
      Constant Field Values

    • INC_SERVLET_PATH

      public static final java.lang.String INC_SERVLET_PATH
      Servlet API include key name: servlet_path
      See Also:
      Constant Field Values

    • servletContext

      protected javax.servlet.ServletContext servletContext
      Servlet (or the web application) context.

    • resourceNamePattern

      protected java.util.regex.Pattern resourceNamePattern
      Either null or a compiled pattern read from ""resource.name.regex"" and used in getScriptUri(HttpServletRequest).

    • resourceNameReplacement

      protected java.lang.String resourceNameReplacement
      The replacement used by the resource name matcher.

    • resourceNameReplaceAll

      protected boolean resourceNameReplaceAll
      The replace method to use on the matcher. 
       true - replaceAll(resourceNameReplacement); (default)
 false - replaceFirst(resourceNameReplacement);

    • verbose

      protected boolean verbose
      Controls almost all log output.

    • encoding

      protected java.lang.String encoding
      Encoding to use, becomes charset part of contentType.

    • reflection

      protected boolean reflection
      Mirrors the static value of the reflection flag in MetaClass. See AbstractHttpServlet#logGROOVY861

    • namePrefix

      protected java.lang.String namePrefix
      a.fink: it was in removeNamePrefix(java.lang.String), but was extracted to var for optimization

  • Constructor Details

    • AbstractHttpServlet

      public AbstractHttpServlet()
      Initializes all fields with default values.

  • Method Details

    • generateNamePrefixOnce

      protected void generateNamePrefixOnce()

    • removeNamePrefix

      protected java.lang.String removeNamePrefix​(java.lang.String name) throws ResourceException
      Throws:
      ResourceException

    • getResourceConnection

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

    • getScriptUri

      protected java.lang.String getScriptUri​(javax.servlet.http.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 java.lang.String applyResourceNameMatcher​(java.lang.String uri)

    • getScriptUriAsFile

      protected java.io.File getScriptUriAsFile​(javax.servlet.http.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​(javax.servlet.ServletConfig config) throws javax.servlet.ServletException
      Overrides the generic init method to set some debug flags.
      Specified by:
      init in interface javax.servlet.Servlet
      Overrides:
      init in class javax.servlet.GenericServlet
      Parameters:
      config - the servlet configuration provided by the container
      Throws:
      javax.servlet.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