我的tomcat启动时出现警告这是怎么回事呢？还有我写servlet 在页面上点击了 不显示东西

警告: The XML schema [XMLSchema.dtd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [datatypes.dtd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [xml.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [web-app_2_2.dtd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [web-app_2_3.dtd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [j2ee_web_services_1_1.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [j2ee_web_services_client_1_1.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [web-app_2_4.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [j2ee_1_4.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [web-app_2_5.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [javaee_5.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [javaee_web_services_1_2.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.
十月 24, 2016 5:38:29 下午 org.apache.tomcat.util.descriptor.DigesterFactory locationFor
警告: The XML schema [javaee_web_services_client_1_2.xsd] could not be found. This is very likely to break XML validation if XML validation is enabled.

启动后页面可以正常访问吗？把JSP页面的代码贴出来看看

你的web.xml或者其他xml文件的命名空间正确吗？
警告是dtd相关的

你的web.xml
你看一下 对不对

xsd约束文件没有被创建或者没有正确地导入