org.mrgeo.services.ServletUtils.java Source code

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/*
 * Copyright 2009-2016 DigitalGlobe, Inc.
 *
 * 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.mrgeo.services;

import org.apache.commons.collections.map.CaseInsensitiveMap;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.IIOException;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.stream.MemoryCacheImageOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Enumeration;

/**
 * Utilities to be used with Servlet requests/responses
 */
public class ServletUtils {
    private static final Logger log = LoggerFactory.getLogger(ServletUtils.class);

    /**
     * Prints request attributes to the debug logger
     * @param request servlet request
     */
    public static void printRequestAttributes(HttpServletRequest request) {
        @SuppressWarnings("rawtypes")
        Enumeration enAttr = request.getAttributeNames();
        while (enAttr.hasMoreElements()) {
            String attributeName = (String) enAttr.nextElement();
            log.debug("Attribute Name: {}, Value: {}", attributeName,
                    (request.getAttribute(attributeName)).toString());
        }
    }

    /**
     * Prints request attributes to the debug logger
     * @param request servlet request
     */
    public static void printRequestURL(HttpServletRequest request) {
        final StringBuffer requestURL = request.getRequestURL();
        final String queryString = request.getQueryString();

        if (queryString == null) {
            log.debug("HTTP Request {}", requestURL.toString());
        } else {
            log.debug("HTTP Request {}?{}", requestURL.toString(), queryString);
        }
    }

    /**
     * Prints request parameters to the debug logger
     * @param request servlet request
     */
    public static void printRequestParams(HttpServletRequest request) {
        @SuppressWarnings("rawtypes")
        Enumeration enParams = request.getParameterNames();
        while (enParams.hasMoreElements()) {
            String paramName = (String) enParams.nextElement();
            log.debug("Attribute Name: {}, Value: {}", paramName, request.getParameter(paramName));
        }
    }

    /**
     * Writes an image to a servlet response
     * @param response servlet response
     * @param image image bytes
     * @throws IOException
     */
    public static void writeImageToResponse(HttpServletResponse response, byte[] image) throws IOException {
        try {
            ImageOutputStream imageStream = new MemoryCacheImageOutputStream(response.getOutputStream());
            imageStream.write(image, 0, image.length);
            response.setContentLength((int) imageStream.length());
            imageStream.close();
        }
        // TODO: remove these catches - This is to prevent seeing the broken pipes exception
        // over and over again in the trace...leave catch in until issue is fixed (#1122)
        catch (IIOException e) {
        } catch (IndexOutOfBoundsException e) {
        }
    }

    /**
     * Validates the existence and type of an HTTP parameter and returns it
     * @param request servlet request
     * @param name parameter name
     * @param type parameter data type
     * @return parameter value
     * @throws Exception if the parameter does not exist or cannot be cast to the requested data type
     */
    public static String validateAndGetParamValue(HttpServletRequest request, String name, String type)
            throws Exception {
        validateParam(request, name, type);
        return getParamValue(request, name);
    }

    /**
     * Validates the existence and type of an HTTP parameter.
     * @param request servlet request
     * @param name parameter name
     * @param type parameter data type
     * @throws Exception if the parameter does not exist or cannot be cast to the requested data type
     */
    public static void validateParam(HttpServletRequest request, String name, String type) throws Exception {
        CaseInsensitiveMap params = new CaseInsensitiveMap(request.getParameterMap());
        if (params.containsKey(name)) {
            String value = ((String[]) params.get(name))[0];
            if (StringUtils.isEmpty(value)) {
                throw new IllegalArgumentException("Missing request parameter: " + name);
            }
            if (type.equals("integer")) {
                try {
                    Integer.parseInt(value);
                } catch (NumberFormatException e) {
                    throw new IllegalArgumentException("Invalid request parameter: " + name);
                }
            }
            if (type.equals("double")) {
                try {
                    Double.parseDouble(value);
                } catch (NumberFormatException e) {
                    throw new IllegalArgumentException("Invalid request parameter: " + name);
                }
            }
        } else {
            throw new IllegalArgumentException("Missing request parameter: " + name);
        }
    }

    /**
     * Retrieves a parameter value from a servlet request
     * @param request servlet request
     * @param name parameter name
     * @return parameter value
     */
    public static String getParamValue(HttpServletRequest request, String name) {
        CaseInsensitiveMap params = new CaseInsensitiveMap(request.getParameterMap());
        if (params.containsKey(name)) {
            return ((String[]) params.get(name))[0];
        }
        return null;
    }
}