Java tutorial
/** * Copyright (C) 2007 - 2014 52North Initiative for Geospatial Open Source * Software GmbH * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * If the program is linked with libraries which are licensed under one of * the following licenses, the combination of the program with the linked * library is not considered a "derivative work" of the program: * * Apache License, version 2.0 * Apache Software License, version 1.0 * GNU Lesser General Public License, version 3 * Mozilla Public License, versions 1.0, 1.1 and 2.0 * Common Development and Distribution License (CDDL), version 1.0 * * Therefore the distribution of the program linked with libraries licensed * under the aforementioned licenses, is permitted by the copyright holders * if the distribution is compliant with both the GNU General Public * License version 2 and the aforementioned licenses. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General * Public License for more details. */ package org.n52.wps.server.request; import java.util.UUID; import java.util.concurrent.Callable; import org.apache.commons.collections.map.CaseInsensitiveMap; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.n52.wps.server.ExceptionReport; import org.n52.wps.server.response.Response; import org.w3c.dom.Document; /** * The client requests some operation from the server. * The request generates a unique reference based on the client, time and a count. * Not secure! Upcoming references are easily guessed or altered. * @see java.rmi.server.UID */ abstract public class Request implements Callable<Response> { protected CaseInsensitiveMap map = null; protected Document doc = null; protected static Logger LOGGER = LoggerFactory.getLogger(Request.class); protected UUID id = null; public static final String SUPPORTED_VERSION = "1.0.0"; public static final String[] SUPPORTED_LANGUAGES = new String[] { "en-US" }; /** * Create a Request based on a CaseInsensitiveMap as input (HTTP GET) * @param map The Map which holds the client input. */ public Request(CaseInsensitiveMap map) throws ExceptionReport { super(); this.map = map; } /** * Create a Request based on a Document as input (HTTP POST) * @param doc The Document which holds the client input. */ public Request(Document doc) throws ExceptionReport { super(); this.doc = doc; } /** * Returns the user input in Document form * @return Document || null if Request(Map, outputstream) was used */ public Document getDocument() { return doc; } /** * Returns the user input in Map form * @return Map || null if Request(Document, OutputStream) was used */ public CaseInsensitiveMap getMap() { return map; } /** * Retrieve a value from an input-map with a lookup-key * @param key The lookup-key * @param map The input-map to look in * @param required If the key-value pair must be in the map. * @return The value of the key-value pair */ public static String getMapValue(String key, CaseInsensitiveMap map, boolean required) throws ExceptionReport { if (map.containsKey(key)) { return ((String[]) map.get(key))[0]; } else if (!required) { LOGGER.warn("Parameter <" + key + "> not found."); return null; } else { //Fix for Bug 904 https://bugzilla.52north.org/show_bug.cgi?id=904 throw new ExceptionReport("Parameter <" + key + "> not specified.", ExceptionReport.MISSING_PARAMETER_VALUE, key); } } /** * Retrieve a value from an input-map with a lookup-key * @param key The lookup-key * @param map The input-map to look in * @param required If the key-value pair must be in the map. * @return The value of the key-value pair */ public static String getMapValue(String key, CaseInsensitiveMap map, boolean required, String[] supportedValues) throws ExceptionReport { if (map.containsKey(key)) { String value = ((String[]) map.get(key))[0]; for (String string : supportedValues) { if (string.equalsIgnoreCase(value)) { return value; } } throw new ExceptionReport("Invalid value for parameter <" + key + ">.", ExceptionReport.INVALID_PARAMETER_VALUE, key); } else if (!required) { LOGGER.warn("Parameter <" + key + "> not found."); return null; } else { //Fix for Bug 904 https://bugzilla.52north.org/show_bug.cgi?id=904 throw new ExceptionReport("Parameter <" + key + "> not specified.", ExceptionReport.MISSING_PARAMETER_VALUE, key); } } /** * Retrieve an array of values from an input-map with a lookup-key * @param key The lookup-key * @param map The input-map to look in * @param required If the key-value pair must be in the map. * @return The array of values of the key-value pair */ public static String[] getMapArray(String key, CaseInsensitiveMap map, boolean required) throws ExceptionReport { if (map.containsKey(key)) { return (String[]) map.get(key); } else if (!required) { LOGGER.warn("Parameter <" + key + "> not found."); return null; } else { //Fix for Bug 904 https://bugzilla.52north.org/show_bug.cgi?id=904 throw new ExceptionReport("Parameter <" + key + "> not specified.", ExceptionReport.MISSING_PARAMETER_VALUE, key); } } /** * Retrieve a value from the client-input-map with a lookup-key * @param The lookup-key * @return The value of the key-value pair */ protected String getMapValue(String key, boolean required) throws ExceptionReport { return Request.getMapValue(key, this.map, required); } /** * Retrieve a value from the client-input-map with a lookup-key * @param The lookup-key * @return The value of the key-value pair */ protected String getMapValue(String key, boolean required, String[] supportedValues) throws ExceptionReport { return Request.getMapValue(key, this.map, required, supportedValues); } /** * Retrieve an array of values from the client-input-map with a lookup-key * @param The lookup-key * @return The array of values of the key-value pair */ protected String[] getMapArray(String key, boolean required) throws ExceptionReport { return Request.getMapArray(key, this.map, required); } /** * Returns the version that the client requested. * @return An array of versions that are compatible with the client */ protected String[] getRequestedVersions(boolean mandatory) throws ExceptionReport { return getMapArray("version", mandatory); } /** * The process (request) on the server could require a specific version on the client * @param version The version that is required on the client * @return True if the required version matches, False otherwise. */ public boolean requireVersion(String version, boolean mandatory) throws ExceptionReport { String[] versions = getRequestedVersions(mandatory); if (mandatory && versions == null) { //Fix for Bug 904 https://bugzilla.52north.org/show_bug.cgi?id=904 throw new ExceptionReport("Parameter <version> not specified.", ExceptionReport.MISSING_PARAMETER_VALUE, "version"); } else if (versions == null && !mandatory) { return true; } for (String v : versions) { //remove possible blanks if (v.trim().equals(version)) { return true; } } return false; } /** * Accumulates the Strings in an array, separated by ", " (without quotes). * @param strings The array to accumulate * @return The accumulated String */ public static String accumulateString(String[] strings) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < strings.length; i++) { String s = strings[i]; if (!(i == strings.length - 1)) { sb.append(s + ", "); } else { sb.append(s); } } return sb.toString(); } public UUID getUniqueId() { if (id == null) { this.id = UUID.randomUUID(); } return id; } /** * Checks, if the language is supported by the WPS. * The language parameter is optional, however, if a wrong language is requested, * an ExceptionReport has to be returned to the client. * * See https://bugzilla.52north.org/show_bug.cgi?id=905. * * @param language The language to be checked. * @throws ExceptionReport If a wrong language is requested, this ExceptionReport will be returned to the client. */ public static void checkLanguageSupported(String language) throws ExceptionReport { for (String supportedLanguage : SUPPORTED_LANGUAGES) { if (supportedLanguage.equals(language)) { return; } } throw new ExceptionReport("The requested language " + language + " is not supported", ExceptionReport.INVALID_PARAMETER_VALUE, "language"); } abstract public Object getAttachedResult(); /** * After creation a Request is handled. This is done by calling this method. * This handling could contain a lot of computations. These computations should * be called from within this method. * @return A Response to the client Request * @see java.util.concurrent.Callable#call() */ abstract public Response call() throws ExceptionReport; /** * There should be some validation required on the (input of the) clients Request. * @return True if the clients Request can be handled without problems, False otherwise */ abstract public boolean validate() throws ExceptionReport; }