CaseIgnoringComparator Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/multipart/CaseIgnoringComparator.java lines 21–56

final class CaseIgnoringComparator implements Comparator<CharSequence>, Serializable {

    private static final long serialVersionUID = 4582133183775373862L;

    static final CaseIgnoringComparator INSTANCE = new CaseIgnoringComparator();

    private CaseIgnoringComparator() {
    }

    @Override
    public int compare(CharSequence o1, CharSequence o2) {
        int o1Length = o1.length();
        int o2Length = o2.length();
        int min = Math.min(o1Length, o2Length);
        for (int i = 0; i < min; i++) {
            char c1 = o1.charAt(i);
            char c2 = o2.charAt(i);
            if (c1 != c2) {
                c1 = Character.toUpperCase(c1);
                c2 = Character.toUpperCase(c2);
                if (c1 != c2) {
                    c1 = Character.toLowerCase(c1);
                    c2 = Character.toLowerCase(c2);
                    if (c1 != c2) {
                        return c1 - c2;
                    }
                }
            }
        }
        return o1Length - o2Length;
    }

    private Object readResolve() {
        return INSTANCE;
    }
}