nextapp.echo2.webrender.service.JavaScriptService Maven / Gradle / Ivy
The newest version!
/*
* This file is part of the Echo Web Application Framework (hereinafter "Echo").
* Copyright (C) 2002-2009 NextApp, Inc.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
package nextapp.echo2.webrender.service;
import java.io.IOException;
import nextapp.echo2.webrender.Connection;
import nextapp.echo2.webrender.Service;
import nextapp.echo2.webrender.util.GZipCompressor;
import nextapp.echo2.webrender.util.JavaScriptCompressor;
import nextapp.echo2.webrender.util.Resource;
/**
* A service which renders JavaScript resource files.
*/
public class JavaScriptService
implements Service {
/**
* Creates a new JavaScript service from the specified
* resource in the CLASSPATH.
*
* @param id the Service id
* @param resourceName the CLASSPATH resource name containing
* the JavaScript content
* @return the created JavaScriptService
*/
public static JavaScriptService forResource(String id, String resourceName) {
String content = Resource.getResourceAsString(resourceName);
return new JavaScriptService(id, content);
}
/** Service identifier. */
private String id;
/** The JavaScript content in plain text. */
private String content;
/** The JavaScript content in GZip compressed form. */
private byte[] gzipContent;
/**
* Creates a new JavaScriptService.
*
* @param id the Service id
* @param content the JavaScript content
*/
public JavaScriptService(String id, String content) {
super();
this.id = id;
this.content = JavaScriptCompressor.compress(content);
try {
gzipContent = GZipCompressor.compress(this.content);
} catch (IOException ex) {
// Should not occur.
throw new RuntimeException("Exception compressing JavaScript source.", ex);
}
}
/**
* @see nextapp.echo2.webrender.Service#getId()
*/
public String getId() {
return id;
}
/**
* DO_NOT_CACHE is returned for JavaScript
* to avoid possibility of ever running out-of-date JavaScript in the
* event an application is updated and redeployed.
*
* @see nextapp.echo2.webrender.Service#getVersion()
*/
public int getVersion() {
return DO_NOT_CACHE;
}
/**
* @see nextapp.echo2.webrender.Service#service(nextapp.echo2.webrender.Connection)
*/
public void service(Connection conn)
throws IOException {
String userAgent = conn.getRequest().getHeader("user-agent");
if (userAgent == null || userAgent.indexOf("MSIE") != -1) {
// Due to behavior detailed Microsoft Knowledge Base Article Id 312496,
// all HTTP compression support is disabled for this browser.
// Due to the fact that ClientProperties information is not necessarily
// available at this stage, browsers which provide deceitful user-agent
// headers will also be affected.
servicePlain(conn);
} else {
String acceptEncoding = conn.getRequest().getHeader("accept-encoding");
if (acceptEncoding != null && acceptEncoding.indexOf("gzip") != -1) {
serviceGZipCompressed(conn);
} else {
servicePlain(conn);
}
}
}
/**
* Renders the JavaScript resource using GZip encoding.
*
* @param conn the relevant Connection
*/
private void serviceGZipCompressed(Connection conn)
throws IOException {
conn.getResponse().setContentType("text/plain");
conn.getResponse().setHeader("Content-Encoding", "gzip");
conn.getOutputStream().write(gzipContent);
}
/**
* Renders the JavaScript resource WITHOUT using GZip encoding.
*
* @param conn the relevant Connection
*/
private void servicePlain(Connection conn)
throws IOException {
conn.getResponse().setContentType("text/plain");
conn.getWriter().print(content);
}
}