When can I get the "java.net.SocketException: Permission denied:connect" message? And how

Posted 2022-12-06 魏大宾

The "java.net.SocketException: Permission denied: connect" exception message may happen when you are working in Application Server or with a client/server environment via VPN connection and you are using Java 7.

The reason is that isCOBOL uses the IPv4 type of sockets and Java 7 brings support for IPv6 sockets on Windows.
So, when you attempt to connect to an IPv4 address then "behind the scenes" it will use an IPv4-mapped IPv6 address.
And if the VPN product doesn't support the IPv6 sockets this exception will happen.

For example, if you want to connect via thin-client and you use any of the following commands:

iscclient -hostname host -port port progname

java com.iscobol.gui.client.Client -hostname host -port port progname

Or if you want to access the Veryant UDBC server started on the server machine and you run the command:

visql -cstring jdbc:veryant:udbc-server-ip:udbc-server-port:database -u user

To solve this problem you have to use the java property java.net.preferIPv4Stack=true

iscclient -J-Djava.net.preferIPv4Stack=true com.iscobol.gui.client.Client -hostname 10.234.10.18 MAIN_PROGR

java -Djava.net.preferIPv4Stack=true com.iscobol.gui.client.Client -hostname 10.234.10.18 MAIN_PROGR

visql -J-Djava.net.preferIPv4Stack=true -cstring jdbc:veryant:10.234.10.18:6789:VERYSAMPLE -u admin