Tegnsæt i applet

skal du ikke bare sætte det rigtige charset i HTTP response fra den ASP side ?

måske. Fandt ud af at sætte min InputStreamReader til at bruge UTF-8. Virker fint. Troede egentlig altid java brugte UTF-8, men det er måske internt. Prøvede at ændre
context.Response.ContentEncoding til Unicode. Det fiksede æøå, men alle mellemrum lignede en firkant.

jeg har leget lidt

package january;

import java.io.*;
import java.net.*;

public class WebPageCharSet {
    private static final int DEFAULT = 1;
    private static final int ISOLATIN1 = 2;
    private static final int UTF8 = 3;
    private static final int AUTODETECT = 4;
    private static String get(String urlstr, int cs) {
        StringBuffer sb = new StringBuffer();
        try {
            URL url = new URL(urlstr);
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.connect();
            if (con.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream is = con.getInputStream();
                byte[] b = new byte[1000];
                int n;
                while ((n = is.read(b)) >= 0) {
                    switch(cs) {
                    case DEFAULT:
                        sb.append(new String(b, 0, n));
                        break;
                    case ISOLATIN1:
                        sb.append(new String(b, 0, n, "ISO8859-1"));
                        break;
                    case UTF8:
                        sb.append(new String(b, 0, n, "UTF-8"));
                        break;
                    case AUTODETECT:
                        sb.append(new String(b, 0, n, con.getContentType().substring("text/html; Charset=".length())));
                        break;
                    }
                }
                is.close();
            }
            con.disconnect();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sb.toString();
    }
    private static void test(boolean isActualUTF8, boolean isLabeledUTF8) {
        System.out.println("Actual: " + (isActualUTF8 ? "UTF-8" : "ISO8859-1"));
        System.out.println("Labeled: " + (isLabeledUTF8 ? "UTF-8" : "ISO8859-1"));
        String urlstr = "http://localhost/" + (isActualUTF8 ? "utf8" : "isolatin1") + ".asp?cs=" + (isLabeledUTF8 ? "utf-8" : "iso8859-1");
        System.out.println("Result (default): " + get(urlstr, DEFAULT).contains("ÆØÅæøå"));
        System.out.println("Result (ISO8859-1): " + get(urlstr, ISOLATIN1).contains("ÆØÅæøå"));
        System.out.println("Result (UTF-8): " + get(urlstr, UTF8).contains("ÆØÅæøå"));
        System.out.println("Result (auto detect): " + get(urlstr, AUTODETECT).contains("ÆØÅæøå"));
    }
    public static void main(String[] args) {
        test(true, true);
        test(true, false);
        test(false, true);
        test(false, false);
    }
}

Actual: UTF-8
Labeled: UTF-8
Result (default): false
Result (ISO8859-1): false
Result (UTF-8): true
Result (auto detect): true
Actual: UTF-8
Labeled: ISO8859-1
Result (default): false
Result (ISO8859-1): false
Result (UTF-8): true
Result (auto detect): false
Actual: ISO8859-1
Labeled: UTF-8
Result (default): true
Result (ISO8859-1): true
Result (UTF-8): false
Result (auto detect): false
Actual: ISO8859-1
Labeled: ISO8859-1
Result (default): true
Result (ISO8859-1): true
Result (UTF-8): false
Result (auto detect): true