In the attached test case, I use a writer to write characters that are invalid for the specified encoding. I would expect an IOException(?) if the characters are not supported for the encoding. However, no exception is thrown. The character transformation appears to be invalid too. What is the correct behavior?


import java.io.OutputStreamWriter;
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class OWWrite1Test {
    public static void main(String[] args) throws Exception {
//these chars are not valid for the encoding
char[] bad_chars = {'\u067E'};
char[] chars2 = null;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(baos, "ISO8859_1");
try {
osw.write(bad_chars);
osw.flush();
String outstr = baos.toString();
chars2 = outstr.toCharArray();
if (bad_chars[0] == chars2[0]) {
System.out.println("Good. Transformation succeeded.");
}
else {
System.out.println("Bad. Transformation failed.");
}
System.exit(0);
}
catch (IOException ioe) {
System.out.println("Good. IOException was thrown as expected.");
System.exit(0);
}
catch (Exception e) {
System.out.println("Bad. Expected IOException but another "
+"exception " +e +" was thrown.");
System.exit(0);
}
    }
}