java.lang.IllegalArgumentException: The character [_] is never valid in a domain name

Question

I took the java JPA project from github through Eclipse, and I created the JAR file and moved it to the cloud server.

JAR files were built on the cloud server, which was successful. However, after installing nginx on another cloud server, I connected to a cloud server with JAR files, but there was an error.

/etc/nginx/nginx.conf

http {
        upstream tomcat_servers {
                server 00.00.00.00:8080;
                server 00.00.00.00:8080;
         }
     }

Error log

java.lang.IllegalArgumentException: The character [_] is never valid in a domain name.
    at org.apache.tomcat.util.http.parser.HttpParser$DomainParseState.next(HttpParser.java:963) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.http.parser.HttpParser.readHostDomainName(HttpParser.java:859) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.http.parser.Host.parse(Host.java:71) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.http.parser.Host.parse(Host.java:45) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.AbstractProcessor.parseHost(AbstractProcessor.java:294) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.http11.Http11Processor.prepareRequest(Http11Processor.java:759) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:343) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_242]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_242]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_242]

So I deleted the existing Tomcat in the cloud server and downloaded it back to 8.5 version, but the Tom Cat version of Error did not change. So after I deleted Tomcat from the cloud, I tried to build JAR files. I thought I would fail, but I'm showing you the log that Tomcat is connected.

Possible Tomcat be embedded in the JAR file?

NOTE: The JPA project server and the nginx server are different servers.

I can't understand this problem. How can I solve this problem?

Answer 1

I changed my name and solved it.

nginx.conf

http {
        upstream tomcatservers {
                server 00.00.00.00:8080;
                server 00.00.00.00:8080;
         }
     }

default

location / {
                proxy_pass   http://tomcatservers;
           }