linux下运行shutdown.sh关闭Tomcat报错:java.net.ConnectException: Connection refuse解决办法

修改tomcat的server.xml之后想重启服务器，运行./shutdown.sh后报错java.net.ConnectException: Connection refuse：

java.net.ConnectException: Connection refused (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:580)
    at java.net.Socket.connect(Socket.java:529)
    at java.net.Socket.(Socket.java:429)
    at java.net.Socket.(Socket.java:209)
    at org.apache.catalina.startup.Catalina.stopServer(Catalina.java:500)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.catalina.startup.Bootstrap.stopServer(Bootstrap.java:371)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:458)

按照网上的杀进程，重启机器都不行，

排查了半天，发现是如下原因