Looks good, a few functional points.
http://codereview.appspot.com/32111/diff/19/1009 File java/gadgets/src/main/java/org/apache/shindig/gadgets/http/AbstractHttpCache.java (right): http://codereview.appspot.com/32111/diff/19/1009#newcode116 Line 116: * - the resize height parameter (sanitized) ...image resize... also I think you can drop the (sanitized) http://codereview.appspot.com/32111/diff/19/1009#newcode150 Line 150: // The old behavior in the code above was to return ownerId as-is. Since ownerId may be I think you can make this a comment on the commit vs. a comment on the code. The reason is fairly obvious. http://codereview.appspot.com/32111/diff/19/1008 File java/gadgets/src/main/java/org/apache/shindig/gadgets/http/CacheKeyBuilder.java (right): http://codereview.appspot.com/32111/diff/19/1008#newcode29 Line 29: public class CacheKeyBuilder { I think this is fine but in the long run I hate how we build keys, I'd rather see something more like a name=value delimited string http://codereview.appspot.com/32111/diff/19/1010 File java/gadgets/src/main/java/org/apache/shindig/gadgets/http/HttpRequest.java (right): http://codereview.appspot.com/32111/diff/19/1010#newcode53 Line 53: private HttpServletRequest parentRequest; rather than delegating to the original http request I think I'd rather create an attribute map and have the values explicitly copied into it. http://codereview.appspot.com/32111/diff/19/1010#newcode421 Line 421: public Integer getResizeWidth() { I dont think going forward we want these methods here. Instead provide a public get/setAttribute(key, value) http://codereview.appspot.com/32111/diff/19/1017 File java/gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/image/BasicImageRewriter.java (right): http://codereview.appspot.com/32111/diff/19/1017#newcode121 Line 121: if (!isResizeRequested && response.getContentLength() < config.getMinThresholdBytes()) { This is a potential DOS attack. Given that this is an open service we have to set limits even for the resize functionality. http://codereview.appspot.com/32111/diff/19/1017#newcode134 Line 134: if (!isResizeRequested && isImageTooLarge(imageInfo)) { Again a DOS vector. http://codereview.appspot.com/32111/diff/19/1016 File java/gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/image/ImageRewriter.java (right): http://codereview.appspot.com/32111/diff/19/1016#newcode28 Line 28: @ImplementedBy(BasicImageRewriter.class) I dont think we want this on by default, it should be opt in http://codereview.appspot.com/32111
