csiro.pidsvc.helper.Http.java Source code

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Here is the source code for csiro.pidsvc.helper.Http.java

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/*
 * CSIRO Open Source Software License Agreement (variation of the BSD / MIT License)
 * 
 * Copyright (c) 2013, Commonwealth Scientific and Industrial Research Organisation (CSIRO)
 * ABN 41 687 119 230.
 * 
 * All rights reserved. This code is licensed under CSIRO Open Source Software
 * License Agreement license, available at the root application directory.
 */

package csiro.pidsvc.helper;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * Simple HTTP request handling.
 * 
 * @author Pavel Golodoniuc, CSIRO Earth Science and Resource Engineering
 */
public class Http {
    private static Logger _logger = LogManager.getLogger(Http.class.getName());

    private static final String PID_SERVICE_ERROR_HTTP_HEADER = "X-PID-Service-Exception";
    private static final String PID_SERVICE_MSG_HTTP_HEADER = "X-PID-Service-Message";

    /**
     * Return specific HTTP response code and add a message to HTTP header.
     * 
     * @param response HttpServletResponse object.
     * @param httpResponseCode HTTP response code.
     * @param exception Exception object.
     */
    public static void returnErrorCode(HttpServletResponse response, int httpResponseCode, Exception exception) {
        try {
            String message = (exception.getMessage() == null ? "" : exception.getMessage())
                    + (exception.getCause() == null ? "" : "\n" + exception.getCause().getMessage());

            StringWriter sw = new StringWriter();
            exception.printStackTrace(new PrintWriter(sw));

            response.addHeader(PID_SERVICE_ERROR_HTTP_HEADER, message);
            response.addHeader(PID_SERVICE_MSG_HTTP_HEADER, sw.toString());
            response.sendError(httpResponseCode, exception.getMessage());
        } catch (IOException e) {
            _logger.debug(e);
        }
    }

    public static String readInputStream(HttpServletRequest request) throws IOException {
        return Stream.readInputStream(request.getInputStream());
    }

    public static String simpleGetRequest(String uri) {
        HttpClient httpClient = new DefaultHttpClient();
        try {
            HttpGet httpGet = new HttpGet(uri);

            // Get the data.
            HttpResponse response = httpClient.execute(httpGet);
            HttpEntity entity = response.getEntity();

            // Return content.
            return EntityUtils.toString(entity);
        } catch (Exception e) {
            _logger.warn("Exception occurred while executing an HTTP request.", e);
            return null;
        } finally {
            httpClient.getConnectionManager().shutdown();
        }
    }

    public static String simpleGetRequestStrict(String uri) {
        HttpClient httpClient = new DefaultHttpClient();
        try {
            HttpGet httpGet = new HttpGet(uri);

            // Get the data.
            HttpResponse response = httpClient.execute(httpGet);
            if (response.getStatusLine().getStatusCode() != 200)
                return null;
            HttpEntity entity = response.getEntity();

            // Return content.
            return EntityUtils.toString(entity);
        } catch (Exception e) {
            _logger.warn("Exception occurred while executing an HTTP request.", e);
            return null;
        } finally {
            httpClient.getConnectionManager().shutdown();
        }
    }
}