错误：Server Tomcat v7.0 Server at localhost was unable to start within 45 seconds
错误告诉我们服务器不能在45秒的时间内启动，我们可以通过修改服务器的配置文件来设置服务器的启动时间。

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

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<servers>
  <server auto-publish-setting="2" auto-publish-time="1" configuration-id="/Servers/Tomcat v7.0 Server at localhost-config" deployDir="wtpwebapps" hostname="localhost" id="Tomcat v7.0 Server at localhost" name="Tomcat v7.0 Server at localhost" runtime-id="Apache Tomcat v7.0" server-type="org.eclipse.jst.server.tomcat.70" server-type-id="org.eclipse.jst.server.tomcat.70" start-timeout="45" stop-timeout="15" testEnvironment="true" timestamp="3">
    <list key="modules" value0="shop::org.eclipse.jst.jee.server:shop::jst.web::3.0"/>
  </server>
</servers>

把其中的start-timeout="45" 改为  start-timeout="100" 或者更长，根据自己项目的大小来调整，然后重新启动服务器就可以了。