在Java中将UTF-8转换为ISO-8859-1 - 如何将其保持为单字节

import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CodingErrorAction;

public class UTF8ToISO8859 {
    public static void main(String[] args) {
        String utf8String = "UTF-8字符串";
        String iso8859String = convertUTF8ToISO8859(utf8String);
        System.out.println("ISO-8859-1字符串: " + iso8859String);
    }

    public static String convertUTF8ToISO8859(String utf8String) {
        Charset charset = Charset.forName("ISO-8859-1");
        CharsetDecoder decoder = charset.newDecoder();
        decoder.onMalformedInput(CodingErrorAction.IGNORE);
        try {
            byte[] iso8859Bytes = decoder.decode(Charset.forName("UTF-8").encode(utf8String)).array();
            return new String(iso8859Bytes, charset);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}