nginx 配置https转发http请求 ，而在jsp页面获取request.getContextPath()时，获取到的是http而不是https，无需修改程序，只需要配置nginx与Tomcat即可

nginx修改：proxy_set_header X-Forwarded-Proto  $scheme;这一句是关键

Tomcat修改：

 <Valve className="org.apache.catalina.valves.RemoteIpValve"
            remoteIpHeader="X-Forwarded-For" protocolHeader="X-Forwarded-Proto" protocolHeaderHttpsValue="https"/>

在Tomcat中添加valve的配置

<Service name="Catalina">

   
    <Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
  
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

    <Engine name="Catalina" defaultHost="localhost">

    
        <Valve className="org.apache.catalina.valves.RemoteIpValve"
            remoteIpHeader="X-Forwarded-For" protocolHeader="X-Forwarded-Proto" protocolHeaderHttpsValue="https"/>
    
      <Realm className="org.apache.catalina.realm.LockOutRealm">
      
               resourceName="UserDatabase"/>
      </Realm>

      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">

       
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log." suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />

      </Host>
    </Engine>
  </Service>