ca.uhn.fhir.rest.client.apache.GZipContentInterceptor.java Source code

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Here is the source code for ca.uhn.fhir.rest.client.apache.GZipContentInterceptor.java

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package ca.uhn.fhir.rest.client.apache;

/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2016 University Health Network
 * %%
 * 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.
 * #L%
 */

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPOutputStream;

import org.apache.http.Header;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.ByteArrayEntity;

import ca.uhn.fhir.rest.client.IClientInterceptor;
import ca.uhn.fhir.rest.client.api.IHttpRequest;
import ca.uhn.fhir.rest.client.api.IHttpResponse;
import ca.uhn.fhir.rest.server.Constants;

/**
 * Client interceptor which GZip compresses outgoing (POST/PUT) contents being uploaded
 * from the client to the server. This can improve performance by reducing network 
 * load time.
 */
public class GZipContentInterceptor implements IClientInterceptor {
    private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(GZipContentInterceptor.class);

    @Override
    public void interceptRequest(IHttpRequest theRequestInterface) {
        HttpRequestBase theRequest = ((ApacheHttpRequest) theRequestInterface).getApacheRequest();
        if (theRequest instanceof HttpEntityEnclosingRequest) {
            Header[] encodingHeaders = theRequest.getHeaders(Constants.HEADER_CONTENT_ENCODING);
            if (encodingHeaders == null || encodingHeaders.length == 0) {
                HttpEntityEnclosingRequest req = (HttpEntityEnclosingRequest) theRequest;

                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                GZIPOutputStream gos;
                try {
                    gos = new GZIPOutputStream(bos);
                    req.getEntity().writeTo(gos);
                    gos.finish();
                } catch (IOException e) {
                    ourLog.warn("Failed to GZip outgoing content", e);
                    return;
                }

                byte[] byteArray = bos.toByteArray();
                ByteArrayEntity newEntity = new ByteArrayEntity(byteArray);
                req.setEntity(newEntity);
                req.addHeader(Constants.HEADER_CONTENT_ENCODING, "gzip");
            }
        }

    }

    @Override
    public void interceptResponse(IHttpResponse theResponse) throws IOException {
        // nothing
    }

}