(solved)javax.naming.NamingException: Cannot create resource instance 

javax.naming.NamingException: Cannot create resource instance
	at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:143)
	at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304)
	at org.apache.naming.NamingContext.lookup(NamingContext.java:793)
	at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
	at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
	at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
	at MyServlet.foo(MyServlet.java:82)
	at MyServlet.doGet(MyServlet.java:34)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:662)

数時間無駄な試行錯誤をした後に context.xml のスペルミスに気づきましたorzorzorzorz

NG:

<Context [...]>
  <Resource [...] type="javx.sql.DataSource" [...] />
</Context>

OK:

<Context [...]>
  <Resource [...] type="javax.sql.DataSource" [...] />
</Context>