直ってませんでした＞＜；
import java.io.*;
class Sample{
public static void main(String args[]) throws IOException{
System.out.write("こんにちわ\n\n".getBytes("MacRoman"));
System.out.write("こんにちわ\n\n".getBytes("MS932"));
System.out.write("こんにちわ\n\n".getBytes("EUC-JP"));
System.out.write("こんにちわ\n\n".getBytes("UTF-8"));
System.out.write("こんにちわ\n\n".getBytes("Unicode"));
System.out.println(System.getProperty("java.runtime.version"));
System.out.println(System.getProperty("os.name"));
System.out.println(System.getProperty("os.version"));
System.out.println(System.getProperty("os.arch"));
System.out.println(System.getProperty("file.encoding"));
System.out.println("Hello World!");
System.out.println("こんにちわ");
}
}

?????
????????
?????d?
こんにちわ
??S0?0k0a0?0
1.5.0_07-164
Mac OS X
10.4.11
i386
MacRoman
Hello World!
?????