Looks good, a few points. Consider replacing JsonConversionUtilTest.assertJsonEquals with JSonAssert calls.
http://codereview.appspot.com/14084/diff/1/8 File java/common/src/main/java/org/apache/shindig/protocol/ApiServlet.java (right): http://codereview.appspot.com/14084/diff/1/8#newcode90 Line 90: Logger.getLogger("org.apache.shindig").log(Level.SEVERE, ee.getCause().getMessage(), ee); this is not SEVERE. Handlers are expected to throw ProtocolException and its subtypes alot, at best this is INFO but probably FINE. http://codereview.appspot.com/14084/diff/1/9 File java/common/src/main/java/org/apache/shindig/protocol/JsonRpcServlet.java (right): http://codereview.appspot.com/14084/diff/1/9#newcode162 Line 162: Map<String, Object> map = Maps.newHashMap(); JSONObject preserved order of fields, may be a good idea to use LinkedHashMap to do the same for readability of the result. http://codereview.appspot.com/14084/diff/1/9#newcode179 Line 179: Map<String, Object> error = new HashMap<String, Object>(2, 1); same ordering comment http://codereview.appspot.com/14084/diff/1/7 File java/common/src/main/java/org/apache/shindig/protocol/conversion/BeanJsonConverter.java (right): http://codereview.appspot.com/14084/diff/1/7#newcode146 Line 146: methods = SETTER_METHODS.get(pojo.getClass()); Encapsulate lines 146-150 into getSetters http://codereview.appspot.com/14084/diff/1/2 File java/social-api/src/test/java/org/apache/shindig/social/opensocial/util/JsonConverterPerformancePerf.java (right): http://codereview.appspot.com/14084/diff/1/2#newcode180 Line 180: // public void testToJsonOnInheritedClassOutput() throws Exception { remove? http://codereview.appspot.com/14084
