Run a shell, with that command -- bash, tcsh, whichever one you normally use.
bash -c "echo | iconv -f utf8 -t Cp930" // or
bash -lc "echo | iconv -f utf8 -t Cp930"
Piping is a shell functionality.
Thus:
Runtime rt = Runtime.getRuntime();
String cmd = "echo | iconv -f utf8 -t Cp930";
rt.exec("bash -c \""+cmd+"\"");
See the bash
manual for invocation options. http://www.gnu.org/software/bash/manual/html_node/Invoking-Bash.html#Invoking-Bash