org.eclipse.emf.ecp.emf2web.json.JSONResponseHandler.java Source code

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Here is the source code for org.eclipse.emf.ecp.emf2web.json.JSONResponseHandler.java

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/*******************************************************************************
 * Copyright (c) 2014-2015 EclipseSource Muenchen GmbH and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * Stefan Dirix - initial API and implementation
 *
 *******************************************************************************/
package org.eclipse.emf.ecp.emf2web.json;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpResponseException;
import org.apache.http.client.ResponseHandler;
import org.apache.http.entity.ContentType;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;

public class JSONResponseHandler<T> implements ResponseHandler<T> {

    @Override
    public T handleResponse(HttpResponse response) throws ClientProtocolException, IOException {
        final StatusLine statusLine = response.getStatusLine();

        final HttpEntity entity = response.getEntity();
        if (statusLine.getStatusCode() >= 300) {
            throw new HttpResponseException(statusLine.getStatusCode(), statusLine.getReasonPhrase());
        }
        if (entity == null) {
            throw new ClientProtocolException("Response contains no content");
        }

        final Gson gson = new GsonBuilder().create();
        final ContentType contentType = ContentType.getOrDefault(entity);
        final Charset charset = contentType.getCharset();

        final Reader reader = new InputStreamReader(entity.getContent(), charset);

        return gson.fromJson(reader, new TypeToken<T>() {
        }.getType());
    }
}