Tech Rocks


An online resource for latest web technologies like Coldfusion, JRun, Pro*C, JQuery, HTML5, PHP, W3C, Java, J2EE, C, C++, ORACLE, PL/SQL, MySql, Ajax, Coldbox, Fusebox, UNIX, JavaScript, NodeJS and much more...

Monday, April 7, 2014

Java Enterprise Edition (Java EE) Technologies on AppEngine


While we do not support the entirety of the Java EE specification, many of its individual components are supported. These include:

  • Java Data Objects (JDO)
  • Java Persistence API (JPA)
  • Java Server Faces (JSF) 1.1 - 2.0
  • Java Server Pages (JSP) + JSTL
  • Java Servlet API 2.4
  • JavaBeans™ Activation Framework (JAF)
  • Java Architecture for XML Binding (JAXB)
  • Java API for XML Web Services (JAX-WS) 4
  • JavaMail
  • XML processing APIs including DOM, SAX, and XSLT
  • 1 For a guide on "converting" between JPA and JDO.

    2 JSF 1.1 appears to be working out-of-the-box. JSF 1.2 and JSF 2.0 should also work if you set the com.sun.faces.enableMultiThreadedStartup context parameter to false to your web.xml file. Setting this parameter to false (it's set to true by default) will prevent additional threads from being spawned. For more information on running JSF 2.0 in App Engine.

    3 JSP session beans are not supported; to enable EL parsing, add <%@page isElIgnored="false" %> to your JSPs and <%@tag isElIgnored="false" %> to your tag files.

    4 JAX-WS is supported for web service clients but not for servers. To write a SOAP server on App Engine you must use javax.xml.soap and JAXB.


    Not supported

    There are various APIs and technologies that are not supported by App Engine at present for various reasons. These include:

  • Enterprise Java Beans (EJB)
  • Java Database Connectivity (JDBC)
  • Java EE™ Connector Architecture (JCA)
  • Java Management Extensions (JMX)
  • Java Message Service (JMS)
  • Java Naming and Directory Interface (JNDI)
  • Remote Method Invocation (RMI)
  • App Engine's underlying datastore is based on BigTable, not a traditional SQL-based RDBMS like MySQL or PostgreSQL. You may either use the low-level datastore API or the JDO or JPA object-relational mapping interfaces provided. Various JDBC wrappers are available for the datastore, and you may still be able to connect to in-memory databases such as the H2 database engine or HSQLDB.


    Post a Comment