出現的問題：
Oct 22, 2018 5:31:10 PM org.apache.coyote.http11.AbstractHttp11Processor process
SEVERE: Error processing request
java.lang.NullPointerException
at org.apache.catalina.connector.Request.setAttribute(Request.java:1563)
解決辦法：
tomcat/conf/server.xml 的protocol 由原來的設置 org.apache.coyote.http11.Http11Protocol 改成 HTTP/1.1
Sets the protocol to handle incoming traffic. The default value is HTTP/1.1 which uses an auto-switching mechanism to select either a non blocking Java NIO based connector or an APR/native based connector. If the PATH (Windows) or LD_LIBRARY_PATH (on most unix systems) environment variables contain the Tomcat native library, the APR/native connector will be used. If the native library cannot be found, the non blocking Java based connector will be used. Note that the APR/native connector has different settings for HTTPS than the Java connectors.
To use an explicit protocol rather than rely on the auto-switching mechanism described above, the following values may be used:
org.apache.coyote.http11.Http11Protocol - blocking Java connector
org.apache.coyote.http11.Http11NioProtocol - non blocking Java NIO connector
org.apache.coyote.http11.Http11Nio2Protocol - non blocking Java NIO2 connector
org.apache.coyote.http11.Http11AprProtocol - the APR/native connector.
Custom implementations may also be used.
Take a look at our Connector Comparison chart. The configuration for both Java connectors is identical, for http and https.
For more information on the APR connector and APR specific SSL settings please visit the APR documentation