Groovy Documentation

## groovy.servlet
[Java] Class AbstractHttpServlet

    java.lang.Object
      javax.servlet.http.HttpServlet
          groovy.servlet.AbstractHttpServlet

All Implemented Interfaces:
  ResourceConnector

    public abstract class AbstractHttpServlet
    extends HttpServlet

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 java.util.regex.Pattern and java.util.regex.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

Authors:
  Christian Stein
  Roshan Dawrani (roshandawrani)

Field Summary
`static java.lang.String` | `CONTENT_TYPE_TEXT_HTML` Content type of the HTTP response.
`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
`protected java.lang.String` | `encoding` Encoding to use, becomes charset part of contentType.
`protected boolean` | `reflection` Mirrors the static value of the reflection flag in MetaClass.
`protected java.util.regex.Matcher` | `resourceNameMatcher` Either `null` or a compiled pattern matcher read from "`resource.name.regex`" and used in AbstractHttpServlet#getScriptUri(HttpServletRequest)#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 ServletContext` | `servletContext` Servlet (or the web application) context.
`protected boolean` | `verbose` Controls almost all log output.

Constructor Summary
`AbstractHttpServlet()` Initializes all fields with default values.

Method Summary
`java.net.URLConnection` | `getResourceConnection(java.lang.String name)` Interface method for ResourceContainer.
`protected java.lang.String` | `getScriptUri(HttpServletRequest request)` Returns the include-aware uri of the script or template file.
`protected java.io.File` | `getScriptUriAsFile(HttpServletRequest request)` Parses the http request for the real script or template source file.
`void` | `init(ServletConfig config)`
`protected void` | `setVariables(ServletBinding binding)` Override this method to set your variables to the Groovy binding.

Field Detail

### CONTENT_TYPE_TEXT_HTML

    public static final java.lang.String CONTENT_TYPE_TEXT_HTML

  Content type of the HTTP response.

### INC_PATH_INFO

    public static final java.lang.String INC_PATH_INFO

  Servlet API include key name: path_info

### INC_REQUEST_URI

    public static final java.lang.String INC_REQUEST_URI

### INC_SERVLET_PATH

    public static final java.lang.String INC_SERVLET_PATH

  Servlet API include key name: servlet_path

### 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

### resourceNameMatcher

    protected java.util.regex.Matcher resourceNameMatcher

  Either `null` or a compiled pattern matcher read from "`resource.name.regex`" and used in AbstractHttpServlet#getScriptUri(HttpServletRequest)#getScriptUri(HttpServletRequest).

### resourceNameReplaceAll

    protected boolean resourceNameReplaceAll

  The replace method to use on the matcher.

       true - replaceAll(resourceNameReplacement); (default)
       false - replaceFirst(resourceNameReplacement);

### resourceNameReplacement

    protected java.lang.String resourceNameReplacement

  The replacement used by the resource name matcher.

### servletContext

    protected ServletContext servletContext

  Servlet (or the web application) context.

### verbose

    protected boolean verbose

  Controls almost all log output.

Constructor Detail

### AbstractHttpServlet

    public AbstractHttpServlet()

  Initializes all fields with default values.

Method Detail

### getResourceConnection

    public java.net.URLConnection getResourceConnection(java.lang.String name)

  Interface method for ResourceContainer. This is used by the GroovyScriptEngine.

### getScriptUri

    protected java.lang.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

### getScriptUriAsFile

    protected java.io.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)

### 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

Groovy Documentation