Tomcat部署项目（JEECG）时报错处理

Error：

  java.lang.IllegalAccessError: class org.xml.sax.helpers.SecuritySupport12 cannot access its superclass org.xml.sax.helpers.SecuritySupport

在部署到Tomcat7.0+JDK7.0的时候，会报这个错误。

解决办法：

  Please add metadata-complete="true" in your web.xml to override default properties of 3.0 for annotations.

    The metadata-complete attribute of the web-app element in a Web application's deployment descriptor specifies whether the Web descriptor and other related deployment descriptors for this module (such as Web service descriptors) are complete

If servlet version is set to 2.4 or an earlier version, the servlet container does not process any annotations.

If the metadata-complete attribute is missing or is set to false, the default value for Servlet 2.5/3.0, and version is set to 2.5/3.0, the servlet container examines the class files of the application for servlet annotations and supports the annotations.

例如：

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"  metadata-complete="true" >