package com.bradmcevoy.http;
import com.bradmcevoy.http.http11.DefaultHttp11ResponseHandler;
import com.bradmcevoy.http.exceptions.BadRequestException;
import java.io.OutputStream;
import java.util.Map;
import java.util.zip.GZIPOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.bradmcevoy.http.exceptions.NotAuthorizedException;
import com.bradmcevoy.http.http11.CacheControlHelper;
import com.bradmcevoy.http.http11.DefaultCacheControlHelper;
import com.bradmcevoy.http.webdav.WebDavResponseHandler;
import com.bradmcevoy.io.BufferingOutputStream;
import com.bradmcevoy.io.FileUtils;
import com.bradmcevoy.io.ReadingException;
import com.bradmcevoy.io.StreamUtils;
import com.bradmcevoy.io.WritingException;
import java.io.InputStream;
import java.util.Date;
import org.apache.commons.io.IOUtils;
/**
* Response Handler which wraps another, and compresses content if appropriate
*
* Usually, this will wrap a DefaultResponseHandler, but custom implementations
* can be wrapped as well.
*
* @author brad
*/
public class CompressingResponseHandler extends AbstractWrappingResponseHandler {
private static final Logger log = LoggerFactory.getLogger( CompressingResponseHandler.class );
/**
* The size to buffer in memory before switching to disk cache.
*/
private int maxMemorySize = 100000;
private CacheControlHelper cacheControlHelper = new DefaultCacheControlHelper();
public CompressingResponseHandler() {
}
public CompressingResponseHandler( WebDavResponseHandler wrapped ) {
super( wrapped );
}
/**
* Defaults to com.bradmcevoy.http.http11.DefaultCacheControlHelper
* @return
*/
public CacheControlHelper getCacheControlHelper() {
return cacheControlHelper;
}
public void setCacheControlHelper( CacheControlHelper cacheControlHelper ) {
this.cacheControlHelper = cacheControlHelper;
}
@Override
public void respondContent( Resource resource, Response response, Request request, Map<String, String> params ) throws NotAuthorizedException, BadRequestException {
if( resource instanceof GetableResource ) {
GetableResource r = (GetableResource) resource;
String acceptableContentTypes = request.getAcceptHeader();
String contentType = r.getContentType( acceptableContentTypes );
if( canCompress( r, contentType, request.getAcceptEncodingHeader() ) ) {
log.trace( "respondContent: compressable" );
// get the zipped content before sending so we can determine its
// compressed size
BufferingOutputStream tempOut = new BufferingOutputStream( maxMemorySize );
try {
OutputStream gzipOut = new GZIPOutputStream( tempOut );
r.sendContent( gzipOut, null, params, contentType );
gzipOut.flush();
gzipOut.close();
tempOut.flush();
} catch( Exception ex ) {
tempOut.deleteTempFileIfExists();
throw new RuntimeException( ex );
} finally {
FileUtils.close( tempOut );
}
log.trace( "respondContent-compressed: " + resource.getClass() );
setRespondContentCommonHeaders( response, resource, Response.Status.SC_OK, request.getAuthorization() );
response.setContentEncodingHeader( Response.ContentEncoding.GZIP );
response.setVaryHeader( "Accept-Encoding" );
Long contentLength = tempOut.getSize();
response.setContentLengthHeader( contentLength );
response.setContentTypeHeader( contentType );
cacheControlHelper.setCacheControl( r, response, request.getAuthorization() );
InputStream in = tempOut.getInputStream();
try {
StreamUtils.readTo( in, response.getOutputStream() );
} catch( ReadingException ex ) {
throw new RuntimeException( ex );
} catch( WritingException ex ) {
log.warn( "exception writing, client probably closed connection", ex );
} finally {
IOUtils.closeQuietly(in);
}
log.trace("finished sending content");
return;
} else {
log.trace( "respondContent: not compressable" );
// We really should set this header, but it causes IE to not cache files (eg images)
//response.setVaryHeader( "Accept-Encoding" );
wrapped.respondContent( resource, response, request, params );
}
} else {
throw new RuntimeException( "Cant generate content for non-Getable resource: " + resource.getClass() );
}
}
protected void setRespondContentCommonHeaders( Response response, Resource resource, Response.Status status, Auth auth ) {
response.setStatus( status );
response.setDateHeader( new Date() );
String etag = wrapped.generateEtag( resource );
if( etag != null ) {
response.setEtag( etag );
}
DefaultHttp11ResponseHandler.setModifiedDate( response, resource, auth );
}
private boolean canCompress( GetableResource r, String contentType, String acceptableEncodings ) {
log.trace( "canCompress: contentType: " + contentType + " acceptable-encodings: " + acceptableEncodings );
if( contentType != null ) {
contentType = contentType.toLowerCase();
boolean contentIsCompressable = contentType.contains( "text" ) || contentType.contains( "css" ) || contentType.contains( "js" ) || contentType.contains( "javascript" );
if( contentIsCompressable ) {
boolean supportsGzip = ( acceptableEncodings != null && acceptableEncodings.toLowerCase().indexOf( "gzip" ) > -1 );
log.trace( "supports gzip: " + supportsGzip );
return supportsGzip;
}
}
return false;
}
public void setMaxMemorySize( int maxMemorySize ) {
this.maxMemorySize = maxMemorySize;
}
public int getMaxMemorySize() {
return maxMemorySize;
}
}