我在Tomcat 7中有一个Web应用程序。 当我关闭Tomcat时，我看到了这些警告（但并非总是如此）

SEVERE: The web application [/MyApplication] created a ThreadLocal
with key of type
[org.apache.xml.security.algorithms.MessageDigestAlgorithm$1] (value
[org.apache.xml.security.algorithms.MessageDigestAlgorithm$1@2e2c2e2c])
and a value of type [java.util.HashMap] (value
[{http://www.w3.org/2000/09/xmldsig#sha1=MESSAGE DIGEST SHA-1}]) but
failed to remove it when the web application was stopped. Threads are
going to be renewed over time to try and avoid a probable memory leak.
Apr 3, 2012 1:56:19 PM org.apache.catalina.loader.WebappClassLoader
checkThreadLocalMapForLeaks   SEVERE: The web application
[/MyApplication] created a ThreadLocal with key of type
[com.sun.xml.bind.v2.ClassFactory$1] (value
[com.sun.xml.bind.v2.ClassFactory$1@25442544]) and a value of type
[java.util.WeakHashMap] (value [{class
com.classes.internal.ContactType=java.lang.ref.WeakReference@17eb17eb,
class
javax.xml.bind.annotation.adapters.HexBinaryAdapter=java.lang.ref.WeakReference@178a178a,
class
com.classes.internal.xjc.ListType=java.lang.ref.WeakReference@181c181c,
class
com.classes.internal.xjc.MessageType=java.lang.ref.WeakReference@17711771,
class
com.classes.internal.xjc.MessageType=java.lang.ref.WeakReference@17011701}])
but failed to remove it when the web application was stopped. Threads
are going to be renewed over time to try and avoid a probable memory
leak.   Apr 3, 2012 1:56:19 PM
org.apache.catalina.loader.WebappClassLoader
checkThreadLocalMapForLeaks   SEVERE: The web application
[/MyApplication] created a ThreadLocal with key of type
[org.apache.xml.security.utils.UnsyncBufferedOutputStream$1] (value
[org.apache.xml.security.utils.UnsyncBufferedOutputStream$1@4a904a90])
and a value of type [byte[]] (value [[B@67486748]) but failed to
remove it when the web application was stopped. Threads are going to
be renewed over time to try and avoid a probable memory leak.

这些警告在关闭时在catalina.out中意味着什么？我看到了我提到的一些JAXB类，但是不能说出问题所在。

有什么帮助吗？