org.dspace.app.ldn.action.SendLDNMessageAction Maven / Gradle / Ivy

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/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE and NOTICE files at the root of the source
 * tree and available online at
 *
 * http://www.dspace.org/license/
 */
package org.dspace.app.ldn.action;

import java.net.URI;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.http.Header;
import org.apache.http.HttpException;
import org.apache.http.HttpHeaders;
import org.apache.http.HttpStatus;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.dspace.app.ldn.model.Notification;
import org.dspace.content.Item;
import org.dspace.core.Context;

/**
 * Action to send LDN Message
 *
 * @author Mohamed Eskander (mohamed.eskander at 4science.com)
 */
public class SendLDNMessageAction implements LDNAction {

    private static final Logger log = LogManager.getLogger(SendLDNMessageAction.class);

    private CloseableHttpClient client = null;

    public SendLDNMessageAction() {
        HttpClientBuilder builder = HttpClientBuilder.create();
        client = builder
            .disableAutomaticRetries()
            .setMaxConnTotal(5)
            .build();
    }

    public SendLDNMessageAction(CloseableHttpClient client) {
        this();
        if (client != null) {
            this.client = client;
        }
    }

    @Override
    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception {
        //TODO authorization with Bearer token should be supported.

        String url = notification.getTarget().getInbox();

        HttpPost httpPost = new HttpPost(url);
        httpPost.addHeader("Content-Type", "application/ld+json");
        ObjectMapper mapper = new ObjectMapper();
        httpPost.setEntity(new StringEntity(mapper.writeValueAsString(notification), "UTF-8"));

        LDNActionStatus result = LDNActionStatus.ABORT;
        // NOTE: Github believes there is a "Potential server-side request forgery due to a user-provided value"
        // This is a false positive because the LDN Service URL is configured by the user from DSpace.
        // See the frontend configuration at [dspace.ui.url]/admin/ldn/services
        try (
            CloseableHttpResponse response = client.execute(httpPost);
            ) {
            if (isSuccessful(response.getStatusLine().getStatusCode())) {
                result = LDNActionStatus.CONTINUE;
            } else if (isRedirect(response.getStatusLine().getStatusCode())) {
                result = handleRedirect(response, httpPost);
            }
        } catch (Exception e) {
            log.error(e);
        }
        return result;
    }

    private boolean isSuccessful(int statusCode) {
        return statusCode == HttpStatus.SC_ACCEPTED ||
            statusCode == HttpStatus.SC_CREATED;
    }

    private boolean isRedirect(int statusCode) {
        //org.apache.http.HttpStatus has no enum value for 308!
        return statusCode == (HttpStatus.SC_TEMPORARY_REDIRECT + 1) ||
            statusCode == HttpStatus.SC_TEMPORARY_REDIRECT;
    }

    private LDNActionStatus handleRedirect(CloseableHttpResponse oldresponse,
                                        HttpPost request) throws HttpException {
        Header[] urls = oldresponse.getHeaders(HttpHeaders.LOCATION);
        String url = urls.length > 0 && urls[0] != null ? urls[0].getValue() : null;
        if (url == null) {
            throw new HttpException("Error following redirect, unable to reach"
                + " the correct url.");
        }
        LDNActionStatus result = LDNActionStatus.ABORT;
        try {
            request.setURI(new URI(url));
            try (
                CloseableHttpResponse response = client.execute(request);
                ) {
                if (isSuccessful(response.getStatusLine().getStatusCode())) {
                    return LDNActionStatus.CONTINUE;
                }
            }
        } catch (Exception e) {
            log.error("Error following redirect:", e);
        }

        return LDNActionStatus.ABORT;
    }
}