edu.unc.lib.dl.ui.service.DjatokaContentService.java Source code

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Here is the source code for edu.unc.lib.dl.ui.service.DjatokaContentService.java

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/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.unc.lib.dl.ui.service;

import java.io.OutputStream;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpClientParams;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

import edu.unc.lib.dl.ui.exception.ClientAbortException;
import edu.unc.lib.dl.ui.util.ApplicationPathSettings;
import edu.unc.lib.dl.ui.util.FileIOUtil;

/**
 * Generates request, connects to, and streams the output from djatoka.  Sets pertinent headers. 
 * @author bbpennel
 */
public class DjatokaContentService {
    private static final Logger LOG = LoggerFactory.getLogger(DjatokaContentService.class);

    @Autowired
    private ApplicationPathSettings applicationPathSettings;

    public void getMetadata(String simplepid, String datastream, OutputStream outStream,
            HttpServletResponse response) {
        this.getMetadata(simplepid, datastream, outStream, response, 1);
    }

    public void getMetadata(String simplepid, String datastream, OutputStream outStream,
            HttpServletResponse response, int retryServerError) {
        HttpClientParams params = new HttpClientParams();
        params.setContentCharset("UTF-8");
        HttpClient client = new HttpClient();
        client.setParams(params);

        StringBuilder path = new StringBuilder(applicationPathSettings.getDjatokaPath());
        path.append("resolver?url_ver=Z39.88-2004&rft_id=")
                .append(applicationPathSettings.getFedoraPathWithoutDefaultPort()).append("/objects/")
                .append(simplepid).append("/datastreams/").append(datastream).append("/content")
                .append("&svc_id=info:lanl-repo/svc/getMetadata");

        GetMethod method = new GetMethod(path.toString());
        try {
            client.executeMethod(method);
            if (method.getStatusCode() == HttpStatus.SC_OK) {
                if (response != null) {
                    response.setHeader("Content-Type", "application/json");
                    response.setHeader("content-disposition", "inline");

                    FileIOUtil.stream(outStream, method);
                }
            } else {
                if ((method.getStatusCode() == 500 || method.getStatusCode() == 404) && retryServerError > 0) {
                    this.getMetadata(simplepid, datastream, outStream, response, retryServerError - 1);
                } else {
                    LOG.error("Unexpected failure: " + method.getStatusLine().toString());
                    LOG.error("Path was: " + method.getURI().getURI());
                }
            }
        } catch (ClientAbortException e) {
            if (LOG.isDebugEnabled())
                LOG.debug("User client aborted request to stream jp2 metadata for " + simplepid, e);
        } catch (Exception e) {
            LOG.error("Problem retrieving metadata for " + path, e);
        } finally {
            method.releaseConnection();
        }
    }

    public void streamJP2(String simplepid, String region, String scale, String rotate, String datastream,
            OutputStream outStream, HttpServletResponse response) {
        this.streamJP2(simplepid, region, scale, rotate, datastream, outStream, response, 1);
    }

    public void streamJP2(String simplepid, String region, String scale, String rotate, String datastream,
            OutputStream outStream, HttpServletResponse response, int retryServerError) {
        HttpClient client = new HttpClient();

        StringBuilder path = new StringBuilder(applicationPathSettings.getDjatokaPath());
        path.append("resolver?url_ver=Z39.88-2004&rft_id=")
                .append(applicationPathSettings.getFedoraPathWithoutDefaultPort()).append("/objects/")
                .append(simplepid).append("/datastreams/").append(datastream).append("/content")
                .append("&svc_id=info:lanl-repo/svc/getRegion&svc_val_fmt=info:ofi/fmt:kev:mtx:jpeg2000&svc.format=image/jpeg")
                .append("&svc.rotate=").append(rotate).append("&svc.level=").append(scale).append("&svc.region=")
                .append(region);

        GetMethod method = new GetMethod(path.toString());

        try {
            client.executeMethod(method);
            if (method.getStatusCode() == HttpStatus.SC_OK) {
                if (response != null) {
                    response.setHeader("Content-Type", "image/jpeg");
                    response.setHeader("content-disposition", "inline");

                    FileIOUtil.stream(outStream, method);
                }
            } else {
                if ((method.getStatusCode() == 500 || method.getStatusCode() == 404) && retryServerError > 0) {
                    this.getMetadata(simplepid, datastream, outStream, response, retryServerError - 1);
                } else {
                    LOG.error("Unexpected failure: " + method.getStatusLine().toString());
                    LOG.error("Path was: " + method.getURI().getURI());
                }
            }
        } catch (ClientAbortException e) {
            if (LOG.isDebugEnabled())
                LOG.debug("User client aborted request to stream jp2 for " + simplepid, e);
        } catch (Exception e) {
            LOG.error("Problem retrieving metadata for " + path, e);
        } finally {
            method.releaseConnection();
        }
    }

    public ApplicationPathSettings getApplicationPathSettings() {
        return applicationPathSettings;
    }

    public void setApplicationPathSettings(ApplicationPathSettings applicationPathSettings) {
        this.applicationPathSettings = applicationPathSettings;
    }
}