org.andromda.cartridges.jsf.renderkit.BinaryFileRenderer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of andromda-jsf-cartridge-components Show documentation
Constains custom JSF components used by the JSF cartridge.
The newest version!
package org.andromda.cartridges.jsf.renderkit;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.render.Renderer;
import javax.servlet.http.HttpServletResponse;

import org.andromda.cartridges.jsf.component.BinaryFile;
import org.apache.commons.lang.StringUtils;


/**
 * A custom renderer for rendering a binary file.
 *
 * @author Chad Brandon
 */
public class BinaryFileRenderer
    extends Renderer
{
    /**
     * Gets the current response instance.
     *
     * @return the current response.
     */
    private HttpServletResponse getResponse(final FacesContext context)
    {
        return (HttpServletResponse)context.getExternalContext().getResponse();
    }

    private static final int BUFFER_SIZE = 4096;

    @Override
    public void encodeBegin(
        FacesContext context,
        UIComponent component)
        throws IOException
    {
        final BinaryFile fileComponent = (BinaryFile)component;
        if (fileComponent.isRendered())
        {
            final HttpServletResponse response = this.getResponse(context);
            final OutputStream stream = response.getOutputStream();

            // - reset the response to clear out any any headers (i.e. so
            //   the user doesn't get "unable to open..." when using IE.)
            response.reset();
            final String fileName = fileComponent.getFileName();
            if (fileComponent.isPrompt() && fileName != null && fileName.trim().length() > 0)
            {
                response.addHeader(
                    "Content-disposition",
                    "attachment; filename=\"" + fileName + '"');
            }

            Object value = fileComponent.getValue();
            final String contentType = fileComponent.getContentType();
            // - for IE we need to set the content type, content length and buffer size and
            //   then the flush the response right away because it seems as if there is any lag time
            //   IE just displays a blank page. With mozilla based clients reports display correctly regardless.
            if (StringUtils.isNotBlank(contentType))
            {
                response.setContentType(contentType);
            }
            final String encoding = fileComponent.getEncoding();
            if (StringUtils.isNotBlank(encoding))
            {
                response.setCharacterEncoding(encoding);
            }
            if (value != null)
            {
                if (value instanceof String)
                {
                    value = StringUtils.isNotBlank(encoding) ? ((String)value).getBytes(encoding) : ((String)value).getBytes();
                }
                if (value instanceof byte[])
                {
                    byte[] file = (byte[])value;
                    response.setBufferSize(file.length);
                    response.setContentLength(file.length);
                    response.flushBuffer();
                    stream.write(file);
                }
                else if (value instanceof InputStream)
                {
                    final InputStream report = (InputStream)value;
                    final byte[] buffer = new byte[BUFFER_SIZE];
                    response.setBufferSize(BUFFER_SIZE);
                    response.flushBuffer();
                    for (int ctr = 0; (ctr = report.read(buffer)) > 0;)
                    {
                        stream.write(buffer, 0, ctr);
                    }
                    stream.flush();
                }
            }
        }
    }

    @Override
    public void encodeEnd(
        final FacesContext context,
        final UIComponent component)
        throws IOException
    {
        final BinaryFile fileComponent = (BinaryFile)component;
        if (fileComponent.isRendered())
        {
            final HttpServletResponse response = this.getResponse(context);
            final OutputStream stream = response.getOutputStream();
            stream.flush();
            stream.close();
        }
    }
}