public String getRelativePath()

in doxia-integration-tools/src/main/java/org/apache/maven/doxia/tools/DefaultSiteTool.java [186:262]
55 lines of code
20 McCabe index (conditional complexity)

    public String getRelativePath(String to, String from) {
        Objects.requireNonNull(to, "to cannot be null");
        Objects.requireNonNull(from, "from cannot be null");

        if (to.contains(":") && from.contains(":")) {
            String toScheme = to.substring(0, to.lastIndexOf(':'));
            String fromScheme = from.substring(0, from.lastIndexOf(':'));
            if (!toScheme.equals(fromScheme)) {
                return to;
            }
        }

        URL toUrl = null;
        URL fromUrl = null;

        String toPath = to;
        String fromPath = from;

        try {
            toUrl = new URL(to);
        } catch (MalformedURLException e) {
            try {
                toUrl = new File(getNormalizedPath(to)).toURI().toURL();
            } catch (MalformedURLException e1) {
                LOGGER.warn("Unable to load a URL for '" + to + "'", e);
                return to;
            }
        }

        try {
            fromUrl = new URL(from);
        } catch (MalformedURLException e) {
            try {
                fromUrl = new File(getNormalizedPath(from)).toURI().toURL();
            } catch (MalformedURLException e1) {
                LOGGER.warn("Unable to load a URL for '" + from + "'", e);
                return to;
            }
        }

        if (toUrl != null && fromUrl != null) {
            // URLs, determine if they share protocol and domain info

            if ((toUrl.getProtocol().equalsIgnoreCase(fromUrl.getProtocol()))
                    && (toUrl.getHost().equalsIgnoreCase(fromUrl.getHost()))
                    && (toUrl.getPort() == fromUrl.getPort())) {
                // shared URL domain details, use URI to determine relative path

                toPath = toUrl.getFile();
                fromPath = fromUrl.getFile();
            } else {
                // don't share basic URL information, no relative available

                return to;
            }
        } else if ((toUrl != null && fromUrl == null) || (toUrl == null && fromUrl != null)) {
            // one is a URL and the other isn't, no relative available.

            return to;
        }

        // either the two locations are not URLs or if they are they
        // share the common protocol and domain info and we are left
        // with their URI information

        String relativePath = getRelativeFilePath(fromPath, toPath);

        if (relativePath == null) {
            relativePath = to;
        }

        if (LOGGER.isDebugEnabled() && !relativePath.toString().equals(to)) {
            LOGGER.debug("Mapped url: " + to + " to relative path: " + relativePath);
        }

        return relativePath;
    }