屏蔽錯誤的原始顯示

在開發Tomcat應用時，難免有各種錯誤，但錯誤不能在發佈時顯示，需要採取措施屏蔽。
在WEB-INF目錄下web.xml中加入如下代碼，即可實現常見出錯屏蔽。
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<ERROR-PAGE><ERROR-CODE>404</ERROR-CODE><LOCATION>/error/error404.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><ERROR-CODE>400</ERROR-CODE><LOCATION>/error/error400.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><ERROR-CODE>500</ERROR-CODE><LOCATION>/error/error500.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><ERROR-CODE>503</ERROR-CODE><LOCATION>/error/error503.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><EXCEPTION-TYPE>java.lang.Exception</EXCEPTION-TYPE><LOCATION>/error/error500.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><EXCEPTION-TYPE>java.lang.NullPointerException</EXCEPTION-TYPE><LOCATION>/error/nullpointer.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><EXCEPTION-TYPE>java.lang.ClassNotFoundException</EXCEPTION-TYPE><LOCATION>/error/classnotfound.jsp</LOCATION></ERROR-PAGE>
<ERROR-PAGE><EXCEPTION-TYPE>java.lang.NoClassDefFoundError</EXCEPTION-TYPE><LOCATION>/error/classnotfound.jsp</LOCATION></ERROR-PAGE>