当启动tomcat时候出现 Server Tomcat v6.0 Server at localhost was unable to start within 45 seconds. If the server requires more time, try increasing the timeout in the server editor. 的错误，那表示你的tomcat启动超时了，有时候你重新启动下就好了，但有时需要重新启动很多次，如果你不想这样的话，你只需修改下tomcat的启动 时间就行了，步骤如下：

修改 workspace\.metadata\.plugins\org.eclipse.wst.server.core\servers.xml文件。

<servers>

<server hostname="localhost" id="JBoss v5.0 at localhost" name="JBoss v5.0 at localhost" runtime-id="JBoss v5.0" server-type="org.eclipse.jst.server.generic.jboss5" server-type-id="org.eclipse.jst.server.generic.jboss5" start-timeout="120" stop- timeout="15" timestamp="0">

<map jndiPort="1099" key="generic_server_instance_properties" port="8090" serverAddress="127.0.0.1" serverConfig="default"/>

</server>

</servers>

把 start-timeout="45" 改为 start-timeout="120" 或者更长 重启eclipse就可以了。

或者在界面修改

Server Tomcat v6.0 Server at localhost was unable to start within 45 seconds