nl.knaw.huygens.timbuctoo.rest.providers.EntityListHTMLProvider.java Source code

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Here is the source code for nl.knaw.huygens.timbuctoo.rest.providers.EntityListHTMLProvider.java

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package nl.knaw.huygens.timbuctoo.rest.providers;

/*
 * #%L
 * Timbuctoo REST api
 * =======
 * Copyright (C) 2012 - 2015 Huygens ING
 * =======
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.List;

import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

import nl.knaw.huygens.timbuctoo.config.TypeRegistry;
import nl.knaw.huygens.timbuctoo.model.Entity;

import org.apache.commons.lang.StringEscapeUtils;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.inject.name.Named;

@Provider
@Produces(MediaType.TEXT_HTML)
@Singleton
public class EntityListHTMLProvider implements MessageBodyWriter<List<? extends Entity>> {

    private final HTMLProviderHelper helper;

    @Inject
    public EntityListHTMLProvider(TypeRegistry registry, @Named("html.defaultstylesheet") String stylesheetLink,
            @Named("public_url") String publicURL) {
        helper = new HTMLProviderHelper(registry, stylesheetLink, publicURL);
    }

    @Override
    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return helper.accept(mediaType) && accept(type) && accept(genericType);
    }

    private boolean accept(Class<?> type) {
        return List.class.isAssignableFrom(type);
    }

    private boolean accept(Type genericType) {
        Class<?> type = null;
        if (genericType instanceof ParameterizedType) {
            Type[] actualTypes = ((ParameterizedType) genericType).getActualTypeArguments();
            if (actualTypes.length == 1) {
                Type actualType = actualTypes[0];
                if (actualType instanceof Class<?>) {
                    type = (Class<?>) actualType;
                } else if (actualType instanceof WildcardType) {
                    Type[] bounds = ((WildcardType) actualType).getUpperBounds();
                    if (bounds.length == 1 && bounds[0] instanceof Class<?>) {
                        type = (Class<?>) bounds[0];
                    }
                }
            }
        }
        return type != null && TypeRegistry.isEntity(type);
    }

    @Override
    public long getSize(List<? extends Entity> docs, Class<?> type, Type genericType, Annotation[] annotations,
            MediaType mediaType) {
        return -1;
    }

    @Override
    public void writeTo(List<? extends Entity> docs, Class<?> type, Type genericType, Annotation[] annotations,
            MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream out) throws IOException {
        helper.writeHeader(out, getTitle(docs));

        JsonGenerator jgen = helper.getGenerator(out);
        ObjectWriter writer = helper.getObjectWriter(annotations);
        for (Entity doc : docs) {
            helper.write(out, "<h2>");
            helper.write(out, getDocTitle(doc));
            helper.write(out, "</h2>");
            writer.writeValue(jgen, doc);
        }

        helper.writeFooter(out);
    }

    private String getTitle(List<? extends Entity> docs) {
        if (docs == null || docs.isEmpty()) {
            return "No documents";
        } else {
            String docTypeName = docs.get(0).getClass().getSimpleName();
            return String.format("%d instances of %s", docs.size(), docTypeName);
        }
    }

    private String getDocTitle(Entity doc) {
        String name = doc.getIdentificationName();
        return (name != null) ? StringEscapeUtils.escapeHtml(name) : "";
    }

}