BlobMessageBodyWriter.java

/*
 * Copyright 2010 Outerthought bvba
 *
 * 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 org.lilyproject.rest.providers.json;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import org.apache.commons.io.output.CloseShieldOutputStream;
import org.lilyproject.repository.api.Blob;
import org.lilyproject.rest.ResourceException;
import org.lilyproject.tools.import_.json.BlobConverter;
import org.lilyproject.util.json.JsonFormat;

@Provider
public class BlobMessageBodyWriter implements MessageBodyWriter<Blob> {
    @Override
    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return type.equals(Blob.class) && mediaType.equals(MediaType.APPLICATION_JSON_TYPE);
    }

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

    @Override
    public void writeTo(Blob blob, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
            throws IOException, WebApplicationException {

        try {
            JsonFormat.serialize(BlobConverter.toJson(blob), new CloseShieldOutputStream(entityStream));
        } catch (Throwable e) {
            // We catch every throwable, since otherwise no one does it and we will not have any trace
            // of Errors that happened.
            throw new ResourceException("Error serializing entity.", e, Response.Status.INTERNAL_SERVER_ERROR.getStatusCode());
        }
    }
}