org.carewebframework.cal.api.ClientUtil.java Source code

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Here is the source code for org.carewebframework.cal.api.ClientUtil.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
 * If a copy of the MPL was not distributed with this file, You can obtain one at
 * http://mozilla.org/MPL/2.0/.
 *
 * This Source Code Form is also subject to the terms of the Health-Related Additional
 * Disclaimer of Warranty and Limitation of Liability available at
 * http://www.carewebframework.org/licensing/disclaimer.
 */
package org.carewebframework.cal.api;

import ca.uhn.fhir.model.api.IResource;
import ca.uhn.fhir.model.dstu.composite.ResourceReferenceDt;
import ca.uhn.fhir.model.primitive.IdDt;
import ca.uhn.fhir.model.primitive.UriDt;
import ca.uhn.fhir.rest.client.GenericClient;

import org.apache.http.impl.client.CloseableHttpClient;

import org.carewebframework.api.spring.SpringUtil;
import org.carewebframework.fhir.client.FhirContext;
import org.carewebframework.fhir.client.HttpClientProxy;

/**
 * FHIR client utility methods.
 */
public class ClientUtil {

    private static GenericClient fhirClient;

    public static FhirContext getFhirContext() {
        return SpringUtil.getBean("fhirContext", FhirContext.class);
    }

    public static void registerHttpClient(String pattern, CloseableHttpClient client) {
        ((HttpClientProxy) getFhirContext().getRestfulClientFactory().getHttpClient()).registerHttpClient(pattern,
                client);
    }

    public static GenericClient getFhirClient() {
        if (fhirClient == null) {
            fhirClient = SpringUtil.getBean("fhirClient", GenericClient.class);
        }

        return fhirClient;
    }

    /**
     * Returns the default FHIR service root url.
     * 
     * @return Default FHIR service root url.
     */
    public static String getServiceRoot() {
        return getFhirClient().getUrlBase();
    }

    /**
     * For urls without a service root, prepends the default service root.
     * 
     * @param url URL to expand.
     * @return URL with a service root prepended.
     */
    public static String expandURL(String url) {
        return url.matches("^.+:/") ? url : getServiceRoot() + url;
    }

    /**
     * Returns a resource of the specified type given a resource reference. If the resource has not
     * been previously fetched, it will be fetched from the server. If the referenced resource is
     * not of the specified type, null is returned.
     * 
     * @param reference A resource reference.
     * @param clazz The desired resource class.
     * @return The corresponding resource.
     */
    @SuppressWarnings("unchecked")
    public static <T extends IResource> T getResource(ResourceReferenceDt reference, Class<T> clazz) {
        IResource resource = getResource(reference);
        return clazz.isInstance(resource) ? (T) resource : null;
    }

    /**
     * Returns a resource given a resource reference. If the resource has not been previously
     * fetched, it will be fetched from the server.
     * 
     * @param reference A resource reference.
     * @return The corresponding resource.
     */
    public static IResource getResource(ResourceReferenceDt reference) {
        if (reference.isEmpty()) {
            return null;
        }

        if (reference.getResource() != null) {
            return reference.getResource();
        }

        IdDt resourceId = reference.getReference();

        if (resourceId == null) {
            throw new IllegalStateException("Reference has no resource ID defined");
        }

        String resourceUrl = resourceId.getValue();

        if (!resourceUrl.startsWith("http")) {
            resourceUrl = getServiceRoot() + resourceUrl;
        }

        IResource resource = getFhirClient().read(new UriDt(resourceUrl));
        reference.setResource(resource);
        return resource;
    }

    /**
     * Enforce static class.
     */
    private ClientUtil() {
    };
}