Задачи | 2 уровень | 4 лекция

StringWriter sw = new StringWriter();
PrintWriter sr = new PrintWriter(sw) {
    @Override
    public String toString() {
        return out.toString();
    }
};

public static String decode(StringReader reader, int key) throws IOException {

public static String getStackTrace(Throwable throwable) {
    PrintStream oldErr = System.err;
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    PrintStream newErr = new PrintStream(byteArrayOutputStream);

    System.setErr(newErr);
    throwable.printStackTrace();
    System.setErr(oldErr);

    return byteArrayOutputStream.toString();
}