App Engine Documentation PHP Standard Environment Documentation API Documentation \google\appengine\util Classes ArrayUtil Various PHP array related utility functions. HttpUtil HTTP related Utilities. StringUtil Various PHP string related utility functions. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated February 22, 2017.