com.sap.cloud.sdk.s4hana.connectivity.ServiceUriBuilder Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2019 SAP SE or an SAP affiliate company. All rights reserved.
 */

package com.sap.cloud.sdk.s4hana.connectivity;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Set;

import javax.annotation.Nonnull;

import com.google.common.collect.Sets;

/**
 * Used to build S/4HANA service URI, considering parameters such as base URI and relative path.
 */
public class ServiceUriBuilder
{
    protected static final String ERP_ENDPOINT_CLOUD = "/sap/bc/rest/sap/fi_map/";
    protected static final String ERP_ENDPOINT_ON_PREMISE = "/sap/hcpint/map/bm/";

    private static final Set testSystemPaths = Sets.newHashSet();

    /**
     * Adds a test system path. For internal use only.
     *
     * @param uri
     *            Adds the path contained in the URI to the collection of endpoints to be removed.
     */
    public static synchronized void registerTestSystem( final URI uri )
    {
        testSystemPaths.add(encloseSlashesIfMissing(uri.getPath()));
    }

    /**
     * Adds a slash ('/') as a prefix if it is not yet present.
     *
     * @param path
     *            The String to prefix with a slash.
     * @return A String guaranteed to start with a slash.
     */
    protected static String prependSlashIfMissing( final String path )
    {
        return path.startsWith("/") ? path : "/" + path;
    }

    /**
     * Adds a slash ('/') as a suffix if it is not yet present.
     *
     * @param path
     *            The String to suffix with a slash.
     * @return A String guaranteed to end with a slash.
     */
    protected static String appendSlashIfMissing( final String path )
    {
        return path.endsWith("/") ? path : path + "/";
    }

    /**
     * Encloses the given String with a slash ('/') if they are not yet present.
     *
     * @param path
     *            The String to pre- and suffix with a slash.
     * @return A String guaranteed to start and end with a slash.
     */
    protected static String encloseSlashesIfMissing( final String path )
    {
        return prependSlashIfMissing(appendSlashIfMissing(path));
    }

    /**
     * Removes all known and registered endpoints from the path of the given URI.
     * 
     * See {@link #registerTestSystem(URI)}, {@link #ERP_ENDPOINT_CLOUD}, and {@link #ERP_ENDPOINT_ON_PREMISE}.
     *
     * @param baseUri
     *            The URI to take the path to be adjusted from.
     * @return The path without any of the registered and known endpoints.
     */
    protected String removeErpEndpointPaths( final URI baseUri )
    {
        String path = encloseSlashesIfMissing(baseUri.getPath());

        path = path.replaceAll(ERP_ENDPOINT_CLOUD, "");
        path = path.replaceAll(ERP_ENDPOINT_ON_PREMISE, "");

        for( final String testSystemPath : testSystemPaths ) {
            path = path.replaceAll(testSystemPath, "");
        }

        return encloseSlashesIfMissing(path);
    }

    /**
     * Builds a ERP service URI for a given relative path.
     * 
     * Therefore the path contained in {@code baseUri} is stripped of all known and registered endpoints (see
     * {@link #registerTestSystem(URI)}) and gets the {@code relativePath} added.
     *
     * @param baseUri
     *            The URI to replace/adjust the path property.
     * @param relativePath
     *            The relative path to be used.
     *
     * @return A new URI object based on the given {@code baseUri}, modified by adjusting the contained path with the
     *         given {@code relativePath}.
     * @throws IllegalArgumentException
     *             If the new URI object could not be created, most likely due to a wrongly formatted relativePath.
     */
    public URI build( @Nonnull final URI baseUri, @Nonnull final String relativePath )
    {
        try {
            final String path = removeErpEndpointPaths(baseUri) + relativePath.replaceFirst("^/", "");

            return new URI(
                baseUri.getScheme(),
                baseUri.getUserInfo(),
                baseUri.getHost(),
                baseUri.getPort(),
                path,
                baseUri.getQuery(),
                baseUri.getFragment());
        }
        catch( final URISyntaxException e ) {
            throw new IllegalArgumentException("Failed to build ERP service URI.", e);
        }
    }
}