package plagiat.filter;

import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;

public class FilterA extends FilterReader {

    public FilterA(Reader in) {
        super(in);
    }

    @Override
    public int read() throws IOException {
        int c = in.read();
        if (c == -1) return -1;
        if (Character.isAlphabetic(c)) return Character.toLowerCase(c);
        if (Character.isDigit(c)) return c;
        return ' ';
    }
}

@@ -346,18 +346,21 @@
 r.is
-Alphabetic
+LetterOrDigit
 (c))
@@ -397,52 +397,8 @@
 c);%0A
-        if (Character.isDigit(c)) return c;%0A
     

replace two methods by one