The Jetspeed project site says that installing the portal server is as simple as running the following command,

java -jar jetspeed-2.1-installer.jar

But things are not that simple if you are behind corporate firewall. I keep getting the following error message on my Win-XP machine which is behind proxy,

org.tp23.antinstaller.InstallException: Not able to load and read
the AntInstaller config at org.tp23.antinstaller.runtime.exe.InputStreamLoadConfigFilter
.exec(InputStreamLoadConfigFilter.java:45)
at org.tp23.antinstaller.runtime.ExecInstall.exec(ExecInstall.java:85)
at org.tp23.antinstaller.selfextract.NonExtractor.main(NonExtractor.java:59)
Caused by: java.io.IOException: DomFactory error: caused by:class java.net.ConnectException:Connection timed out: connect
at org.tp23.antinstaller.runtime.exe.LoadConfigFilter
.readConfig(LoadConfigFilter.java:179)

The installer uses few xml configuration files which are later validated using their corresponding DTDs. The program tries to load the DTDs from internet but gets blocked by the proxy. Java does not pick up proxy details automatically from the IE/FF setting. So one needs to supply the proxy details in environment. It can like,

java -Dhttp.proxyHost=<value> -Dhttp.proxyPort=<value> -jar jetspeed-2.1-installer.jar

The solution may look very trivial but it did take quite sometime to figure out the actual problem. The documentation at the Jetspeed side didn’t help much. They have this reported as a bug and it can be found in their Jira tracker. But i think this should go in as a FAQ entry or under special instructions section for windows installation guide. I am posting it here for a quick reference for others. They need not go digging in the issue tracker to solve it.