/*
* Copyright 2003-2013 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package groovy.servlet;
import groovy.lang.Closure;
import groovy.util.GroovyScriptEngine;
import groovy.util.ResourceException;
import groovy.util.ScriptException;
import java.io.IOException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.codehaus.groovy.runtime.GroovyCategorySupport;
/**
* This servlet will run Groovy scripts as Groovlets. Groovlets are scripts
* with these objects implicit in their scope:
*
* <ul>
* <li>request - the HttpServletRequest</li>
* <li>response - the HttpServletResponse</li>
* <li>application - the ServletContext associated with the servlet</li>
* <li>session - the HttpSession associated with the HttpServletRequest</li>
* <li>out - the PrintWriter associated with the ServletRequest</li>
* </ul>
*
* <p>Your script sources can be placed either in your web application's normal
* web root (allows for subdirectories) or in /WEB-INF/groovy/* (also allows
* subdirectories).
*
* <p>To make your web application more groovy, you must add the GroovyServlet
* to your application's web.xml configuration using any mapping you like, so
* long as it follows the pattern *.* (more on this below). Here is the
* web.xml entry:
*
* <pre>
* <servlet>
* <servlet-name>Groovy</servlet-name>
* <servlet-class>groovy.servlet.GroovyServlet</servlet-class>
* </servlet>
*
* <servlet-mapping>
* <servlet-name>Groovy</servlet-name>
* <url-pattern>*.groovy</url-pattern>
* <url-pattern>*.gdo</url-pattern>
* </servlet-mapping>
* </pre>
*
* <p>The URL pattern does not require the "*.groovy" mapping. You can, for
* example, make it more Struts-like but groovy by making your mapping "*.gdo".
*
* @author Sam Pullara
* @author Mark Turansky (markturansky at hotmail.com)
* @author Guillaume Laforge
* @author Christian Stein
* @author Marcel Overdijk
*
* @see groovy.servlet.ServletBinding
*/
public class GroovyServlet extends AbstractHttpServlet {
/**
* The script engine executing the Groovy scripts for this servlet
*/
private GroovyScriptEngine gse;
/**
* Initialize the GroovyServlet.
*
* @throws ServletException
* if this method encountered difficulties
*/
public void init(ServletConfig config) throws ServletException {
super.init(config);
// Set up the scripting engine
gse = createGroovyScriptEngine();
servletContext.log("Groovy servlet initialized on " + gse + ".");
}
/**
* Handle web requests to the GroovyServlet
*/
public void service(HttpServletRequest request, HttpServletResponse response) throws IOException {
// Get the script path from the request - include aware (GROOVY-815)
final String scriptUri = getScriptUri(request);
// Set it to HTML by default
response.setContentType("text/html; charset="+encoding);
// Set up the script context
final ServletBinding binding = new ServletBinding(request, response, servletContext);
setVariables(binding);
// Run the script
try {
Closure closure = new Closure(gse) {
public Object call() {
try {
return ((GroovyScriptEngine) getDelegate()).run(scriptUri, binding);
} catch (ResourceException e) {
throw new RuntimeException(e);
} catch (ScriptException e) {
throw new RuntimeException(e);
}
}
};
GroovyCategorySupport.use(ServletCategory.class, closure);
} catch (RuntimeException runtimeException) {
StringBuilder error = new StringBuilder("GroovyServlet Error: ");
error.append(" script: '");
error.append(scriptUri);
error.append("': ");
Throwable e = runtimeException.getCause();
/*
* Null cause?!
*/
if (e == null) {
error.append(" Script processing failed.\n");
error.append(runtimeException.getMessage());
if (runtimeException.getStackTrace().length > 0)
error.append(runtimeException.getStackTrace()[0].toString());
servletContext.log(error.toString());
System.err.println(error.toString());
runtimeException.printStackTrace(System.err);
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, error.toString());
return;
}
/*
* Resource not found.
*/
if (e instanceof ResourceException) {
error.append(" Script not found, sending 404.");
servletContext.log(error.toString());
System.err.println(error.toString());
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
/*
* Other internal error. Perhaps syntax?!
*/
servletContext.log("An error occurred processing the request", runtimeException);
error.append(e.getMessage());
if (e.getStackTrace().length > 0)
error.append(e.getStackTrace()[0].toString());
servletContext.log(e.toString());
System.err.println(e.toString());
runtimeException.printStackTrace(System.err);
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e.toString());
}
}
/**
* Hook method to setup the GroovyScriptEngine to use.<br>
* Subclasses may override this method to provide a custom engine.
*/
protected GroovyScriptEngine createGroovyScriptEngine(){
return new GroovyScriptEngine(this);
}
}