/*
* BeanShell Web
* Copyright (C) 2012 Stefano Fornari
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU Affero General Public License version 3 as published by
* the Free Software Foundation with the addition of the following permission
* added to Section 15 as permitted in Section 7(a): FOR ANY PART OF THE COVERED
* WORK IN WHICH THE COPYRIGHT IS OWNED BY Stefano Fornari, Stefano Fornari
* DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA.
*/
package ste.web.http.velocity;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.URI;
import java.net.URISyntaxException;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.entity.BasicHttpEntity;
import org.apache.http.entity.ContentType;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpRequestHandler;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import static ste.web.beanshell.Constants.*;
import ste.web.http.HttpSessionContext;
import ste.web.http.QueryString;
/**
*
* @author ste
*/
public class VelocityHandler implements HttpRequestHandler {
// --------------------------------------------------------------- Constants
// ------------------------------------------------------------ Private data
private VelocityEngine engine;
private String viewsFolder;
// ------------------------------------------------------------ Constructors
public VelocityHandler(final String webroot) {
if (webroot == null) {
throw new IllegalArgumentException("webroot can not be null");
}
engine = new VelocityEngine();
engine.setProperty("file.resource.loader.path", webroot);
engine.setProperty("file.resource.loader.class", "org.apache.velocity.runtime.resource.loader.FileResourceLoader");
engine.setProperty( "resource.loader", "file" );
engine.init();
setViewsFolder(null);
}
public VelocityHandler(final String webroot, final String viewsFolder) {
this(webroot);
setViewsFolder(viewsFolder);
}
// ---------------------------------------------------------- Public methods
/**
* @return the viewsFolder
*
*/
public String getViewsFolder() {
return viewsFolder;
}
/**
* Sets the folder where views are located. If the the given value is null,
* it defaults to DEFAULT_VIEWS_PREFIX.
*
* @param viewsFolder the viewsFolder to set - NULL
*/
public void setViewsFolder(final String viewsFolder) {
if (viewsFolder == null) {
this.viewsFolder = DEFAULT_VIEWS_PREFIX;
} else {
//
// let's fix a common mistake :)
//
this.viewsFolder = (!viewsFolder.startsWith("/"))
? ('/' + viewsFolder)
: viewsFolder
;
}
}
@Override
public void handle(HttpRequest request,
HttpResponse response,
HttpContext context) throws HttpException, IOException {
String view = (String)context.getAttribute(ATTR_VIEW);
if (view == null) {
return;
}
view = getViewPath(request.getRequestLine().getUri(), view);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Writer out = new OutputStreamWriter(baos);
try {
Template t = engine.getTemplate(view);
t.merge(buildContext(request, (HttpSessionContext)context), out); out.flush();
} catch (ResourceNotFoundException e) {
response.setStatusLine(HttpVersion.HTTP_1_1, HttpStatus.SC_NOT_FOUND, "View " + view + " not found.");
return;
} catch (ParseErrorException e) {
throw new HttpException("Parse error evaluating " + view + ": " + e, e);
} catch (MethodInvocationException e) {
throw new HttpException("Method invocation error evaluating " + view + ": " + e, e);
}
BasicHttpEntity body = (BasicHttpEntity)response.getEntity();
body.setContentLength(baos.size());
body.setContent(new ByteArrayInputStream(baos.toByteArray()));
if ((body.getContentType() == null) || StringUtils.isBlank(body.getContentType().getValue())) {
body.setContentType(ContentType.TEXT_HTML.getMimeType());
}
}
/**
* @return the engine
*/
public VelocityEngine getEngine() {
return engine;
}
// --------------------------------------------------------- Private methods
/**
* Creates a velocity context filling it with all request parameters and
* attributes (the former overwrite the latter).
*
* @param request the request to create the context upon
*
* @return the newly created context
*/
private VelocityContext buildContext(HttpRequest request, HttpSessionContext httpContext) {
VelocityContext context = new VelocityContext();
for (String name: httpContext.keySet()) {
context.put(name, httpContext.getAttribute(name));
}
try {
URI uri = new URI(request.getRequestLine().getUri());
QueryString qs = QueryString.parse(uri.getQuery());
for (String name: qs.getNames()) {
context.put(name, qs.get(name));
}
} catch (URISyntaxException x) {
//
// if the URL is marformed, there is nothing to do here...
//
}
return context;
}
private String getViewPath(final String uri, final String view)
throws HttpException {
try {
File uriFile = new File(new URI(uri).getPath());
File viewFile = new File(
uriFile.getParent(),
new File(
viewsFolder,
view
).getPath()
);
return viewFile.getPath();
} catch (URISyntaxException x) {
throw new HttpException("URI syntax error for '" + uri + "'", x);
}
}
}