推荐方案
另外更推荐的方法是通过 Tomcat 的配置文件完成，而不是修改代码，具体配置方法为：
在 conf/server.xml 配置文件中的 <Host> 配置项中添加如下配置：
<Valve className="org.apache.catalina.valves.ErrorReportValve" showReport="false" showServerInfo="false" />
配置项说明：
- showReport：默认值为true，默认显示报错信息
- showServerInfo：默认值为true，默认显示Tomcat的版本号
其他方案
一般情况下，软件的漏洞信息和特定版本，特定操作系统是相关的，因此，软件的版本号以及操作系统类型对攻击者来说是很有价值的。
在默认情况下，Tomcat会在返回信息中把自身的版本号，操作系统类型都显示出来，如下图：
这样做会造成潜在的安全风险，导致不必要的攻击行为。
在Ubuntu 14.04系统上隐藏Tomcat-7.0.52的版本号与操作系统类型的方法如下：
$ cd ~ $ mkdir catalina $ cd catalina $ cp /usr/share/tomcat7/lib/catalina.jar . $ unzip catalina.jar $ cd org/apache/catalina/util $ vim ServerInfo.properties
可以看到里面的内容如下：
# Licensed to the Apache Software Foundation (ASF) under one or more # contributor license agreements. See the NOTICE file distributed with # this work for additional information regarding copyright ownership. # The ASF licenses this file to You under the Apache License, Version 2.0 # (the "License"); you may not use this file except in compliance with # the License. You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. server.info=Apache Tomcat/7.0.52 (Ubuntu) server.number=7.0.52.0 server.built=Jun 30 2016 01:59:37
直接注释掉里面的内容，如下：
# Licensed to the Apache Software Foundation (ASF) under one or more # contributor license agreements. See the NOTICE file distributed with # this work for additional information regarding copyright ownership. # The ASF licenses this file to You under the Apache License, Version 2.0 # (the "License"); you may not use this file except in compliance with # the License. You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # server.info=Apache Tomcat/7.0.52 (Ubuntu) # server.number=7.0.52.0 # server.built=Jun 30 2016 01:59:37
修改完成后，把修改完成的数据存储到catalina.jar中。
$ cd ~ $ cd catalina $ jar uvf catalina.jar org/apache/catalina/util/ServerInfo.properties
把修改后的catalina.jar放回到Tomcat的目录下面:
$ cd ~ $ cd catalina $ sudo unlink /usr/share/tomcat7/lib/catalina.jar $ sudo mv /usr/share/java/catalina.jar /usr/share/java/catalina.jar.old $ sudo cp catalina.jar /usr/share/java/ $ sudo chmod +r /usr/share/java/catalina.jar $ cd /usr/share/tomcat7/lib $ sudo ln -s ../../java/catalina.jar catalina.jar
重启Tomcat的服务
$ sudo service tomcat7 restart
修改后的结果如下图所示，已经没有系统类型信息了，仅仅返回了一个404错误。
至于如何隐藏Apache的版本号，参考链接 Ubuntu 14.04隐藏Apache-2.4的版本号与操作系统类型