org.getobjects.appserver.publisher.GoResource.java Source code

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Here is the source code for org.getobjects.appserver.publisher.GoResource.java

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/*
  Copyright (C) 2007-2008 Helge Hess
    
  This file is part of Go.
    
  Go is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.
    
  Go 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 Lesser General Public
  License for more details.
    
  You should have received a copy of the GNU Lesser General Public
  License along with Go; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/
package org.getobjects.appserver.publisher;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.getobjects.appserver.core.WOContext;
import org.getobjects.appserver.core.WOElement;
import org.getobjects.appserver.core.WOMessage;
import org.getobjects.appserver.core.WOResponse;

/**
 * GoResource
 * <p>
 * This GoObject takes a URL and delivers its contents as a resource. Eg its
 * used by GoProduct to deliver public product resources.
 * <p>
 * Note: this object supports nested queries. Eg /www/images/myimage.gif.
 */
public class GoResource extends WOElement implements IGoObject {
    protected static final Log log = LogFactory.getLog("GoResource");

    protected URL url;

    public GoResource(final URL _url) {
        this.url = _url;
    }

    /* generate response */

    public static String mimeTypeForPath(final String _path) {
        // TODO: fix this crap and use some real MIME/ext object

        int idx = _path.lastIndexOf('.');
        if (idx < 0) {
            log.error("could not detect MIME type for path: " + _path);
            return null;
        }

        String mimeType = null;
        String ext = _path.substring(idx + 1);
        if (ext.equals("css"))
            mimeType = "text/css";
        else if (ext.equals("txt"))
            mimeType = "text/plain";
        else if (ext.equals("js"))
            mimeType = "text/javascript";
        else if (ext.equals("gif"))
            mimeType = "image/gif";
        else if (ext.equals("png"))
            mimeType = "image/png";
        else if (ext.equals("jpg") || ext.equals("jpeg"))
            mimeType = "image/jpeg";
        else if (ext.equals("html"))
            mimeType = "text/html";
        else
            log.error("MIME type unknown for extension '" + ext + "': " + _path);

        return mimeType;
    }

    protected int expirationIntervalForMimeType(final String _mimeType) {
        return 3600 /* 1 hour */;
    }

    @Override
    public void appendToResponse(final WOResponse _r, final WOContext _ctx) {
        URLConnection con = null;
        try {
            con = this.url.openConnection();
        } catch (IOException coe) {
            log.warn("could not open connection to url: " + this.url);
            _r.setStatus(WOMessage.HTTP_STATUS_NOT_FOUND);
            return;
        }

        /* open stream */

        InputStream is = null;
        try {
            is = con.getInputStream();
        } catch (IOException ioe) {
            log.warn("could not open stream to url: " + this.url);
            _r.setStatus(WOMessage.HTTP_STATUS_NOT_FOUND);
            return;
        }

        /* transfer */

        try {
            String mimeType = con.getContentType();
            if (mimeType == null || "content/unknown".equals(mimeType))
                mimeType = mimeTypeForPath(this.url.getPath());

            if (mimeType == null)
                mimeType = "application/octet-stream";

            _r.setHeaderForKey(mimeType, "content-type");
            _r.setHeaderForKey("" + con.getContentLength(), "content-length");

            /* setup caching headers */

            Date now = new Date();
            GregorianCalendar cal = new GregorianCalendar();

            cal.setTime(new Date(con.getLastModified()));
            _r.setHeaderForKey(WOMessage.httpFormatDate(cal), "last-modified");

            cal.setTime(now);
            _r.setHeaderForKey(WOMessage.httpFormatDate(cal), "date");

            cal.add(Calendar.SECOND, this.expirationIntervalForMimeType(mimeType));
            _r.setHeaderForKey(WOMessage.httpFormatDate(cal), "expires");

            /* start streaming */

            _r.enableStreaming();

            byte[] buffer = new byte[0xFFFF];
            for (int len; (len = is.read(buffer)) != -1;)
                _r.appendContentData(buffer, len);
        } catch (IOException e) {
            log.error("IO error trying to deliver resource: " + this.url, e);
            _r.setStatus(WOMessage.HTTP_STATUS_INTERNAL_ERROR);
        } finally {
            try {
                if (is != null)
                    is.close();
            } catch (IOException e) {
                log.warn("could not close URL input stream: " + this.url, e);
            }
        }
    }

    /* recursive lookup */

    public Object lookupName(String _name, IGoContext _ctx, boolean _acquire) {
        /* only process names, don't try to be smart */
        if ("/".equals(_name) || "..".equals(_name) || ".".equals(_name))
            return null;

        URL nurl = null;
        try {
            // ugly hack
            String s = this.url.toExternalForm();
            if (!s.endsWith("/"))
                s += "/";
            nurl = new URL(s + _name);
        } catch (MalformedURLException e) {
            return e;
        }
        if (nurl == null)
            return null;

        return new GoResource(nurl);
    }

    /* description */

    @Override
    public void appendAttributesToDescription(final StringBuilder _d) {
        super.appendAttributesToDescription(_d);

        if (this.url != null)
            _d.append(" url=" + this.url);
    }
}