If you got an error when connecting a remote server with javaws jnlp file like that:
java.io.FileNotFoundException: /home/<username>/.java/deployment/security/trusted.certs (No such file or directory)
you need to install ca-certificates-java package and copy /etc/ssl/certs/java/cacerts file to related location like that:
$ sudo apt-get install ca-certificates-java
$ mkdir -p ~/.java/deployment/security
$ cp /etc/ssl/certs/java/cacerts ~/.java/deployment/security/trusted.certs