Java tutorial
package ca.uhn.fhir.util; import static org.apache.commons.lang3.StringUtils.defaultIfBlank; import static org.apache.commons.lang3.StringUtils.isBlank; import java.io.UnsupportedEncodingException; import java.net.MalformedURLException; import java.net.URL; import java.net.URLDecoder; import java.net.URLEncoder; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.StringTokenizer; import ca.uhn.fhir.model.primitive.IdDt; import ca.uhn.fhir.rest.server.Constants; import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException; /* * #%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% */ public class UrlUtil { private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(UrlUtil.class); /** * Resolve a relative URL - THIS METHOD WILL NOT FAIL but will log a warning and return theEndpoint if the input is invalid. */ public static String constructAbsoluteUrl(String theBase, String theEndpoint) { if (theEndpoint == null) { return null; } if (isAbsolute(theEndpoint)) { return theEndpoint; } if (theBase == null) { return theEndpoint; } try { return new URL(new URL(theBase), theEndpoint).toString(); } catch (MalformedURLException e) { ourLog.warn( "Failed to resolve relative URL[" + theEndpoint + "] against absolute base[" + theBase + "]", e); return theEndpoint; } } public static String constructRelativeUrl(String theParentExtensionUrl, String theExtensionUrl) { if (theParentExtensionUrl == null) { return theExtensionUrl; } if (theExtensionUrl == null) { return theExtensionUrl; } int parentLastSlashIdx = theParentExtensionUrl.lastIndexOf('/'); int childLastSlashIdx = theExtensionUrl.lastIndexOf('/'); if (parentLastSlashIdx == -1 || childLastSlashIdx == -1) { return theExtensionUrl; } if (parentLastSlashIdx != childLastSlashIdx) { return theExtensionUrl; } if (!theParentExtensionUrl.substring(0, parentLastSlashIdx) .equals(theExtensionUrl.substring(0, parentLastSlashIdx))) { return theExtensionUrl; } if (theExtensionUrl.length() > parentLastSlashIdx) { return theExtensionUrl.substring(parentLastSlashIdx + 1); } return theExtensionUrl; } /** * URL encode a value */ public static String escape(String theValue) { if (theValue == null) { return null; } try { return URLEncoder.encode(theValue, "UTF-8"); } catch (UnsupportedEncodingException e) { throw new Error("UTF-8 not supported on this platform"); } } public static boolean isAbsolute(String theValue) { String value = theValue.toLowerCase(); return value.startsWith("http://") || value.startsWith("https://"); } public static boolean isValid(String theUrl) { if (theUrl == null || theUrl.length() < 8) { return false; } String url = theUrl.toLowerCase(); if (url.charAt(0) != 'h') { return false; } if (url.charAt(1) != 't') { return false; } if (url.charAt(2) != 't') { return false; } if (url.charAt(3) != 'p') { return false; } int slashOffset; if (url.charAt(4) == ':') { slashOffset = 5; } else if (url.charAt(4) == 's') { if (url.charAt(5) != ':') { return false; } slashOffset = 6; } else { return false; } if (url.charAt(slashOffset) != '/') { return false; } if (url.charAt(slashOffset + 1) != '/') { return false; } return true; } public static void main(String[] args) { System.out.println(escape("http://snomed.info/sct?fhir_vs=isa/126851005")); } public static Map<String, String[]> parseQueryString(String theQueryString) { HashMap<String, List<String>> map = new HashMap<String, List<String>>(); parseQueryString(theQueryString, map); return toQueryStringMap(map); } public static Map<String, String[]> parseQueryStrings(String... theQueryString) { HashMap<String, List<String>> map = new HashMap<String, List<String>>(); for (String next : theQueryString) { parseQueryString(next, map); } return toQueryStringMap(map); } private static Map<String, String[]> toQueryStringMap(HashMap<String, List<String>> map) { HashMap<String, String[]> retVal = new HashMap<String, String[]>(); for (Entry<String, List<String>> nextEntry : map.entrySet()) { retVal.put(nextEntry.getKey(), nextEntry.getValue().toArray(new String[nextEntry.getValue().size()])); } return retVal; } private static void parseQueryString(String theQueryString, HashMap<String, List<String>> map) { String query = theQueryString; if (query.startsWith("?")) { query = query.substring(1); } StringTokenizer tok = new StringTokenizer(query, "&"); while (tok.hasMoreTokens()) { String nextToken = tok.nextToken(); if (isBlank(nextToken)) { continue; } int equalsIndex = nextToken.indexOf('='); String nextValue; String nextKey; if (equalsIndex == -1) { nextKey = nextToken; nextValue = ""; } else { nextKey = nextToken.substring(0, equalsIndex); nextValue = nextToken.substring(equalsIndex + 1); } nextKey = unescape(nextKey); nextValue = unescape(nextValue); List<String> list = map.get(nextKey); if (list == null) { list = new ArrayList<String>(); map.put(nextKey, list); } list.add(nextValue); } } //@formatter:off /** * Parse a URL in one of the following forms: * <ul> * <li>[Resource Type]?[Search Params] * <li>[Resource Type]/[Resource ID] * <li>[Resource Type]/[Resource ID]/_history/[Version ID] * </ul> */ //@formatter:on public static UrlParts parseUrl(String theUrl) { String url = theUrl; UrlParts retVal = new UrlParts(); if (url.startsWith("http")) { if (url.startsWith("/")) { url = url.substring(1); } int qmIdx = url.indexOf('?'); if (qmIdx != -1) { retVal.setParams(defaultIfBlank(url.substring(qmIdx + 1), null)); url = url.substring(0, qmIdx); } IdDt id = new IdDt(url); retVal.setResourceType(id.getResourceType()); retVal.setResourceId(id.getIdPart()); retVal.setVersionId(id.getVersionIdPart()); return retVal; } else { if (url.matches("\\/[a-zA-Z]+\\?.*")) { url = url.substring(1); } int nextStart = 0; boolean nextIsHistory = false; for (int idx = 0; idx < url.length(); idx++) { char nextChar = url.charAt(idx); boolean atEnd = (idx + 1) == url.length(); if (nextChar == '?' || nextChar == '/' || atEnd) { int endIdx = (atEnd && nextChar != '?') ? idx + 1 : idx; String nextSubstring = url.substring(nextStart, endIdx); if (retVal.getResourceType() == null) { retVal.setResourceType(nextSubstring); } else if (retVal.getResourceId() == null) { retVal.setResourceId(nextSubstring); } else if (nextIsHistory) { retVal.setVersionId(nextSubstring); } else { if (nextSubstring.equals(Constants.URL_TOKEN_HISTORY)) { nextIsHistory = true; } else { throw new InvalidRequestException("Invalid FHIR resource URL: " + url); } } if (nextChar == '?') { if (url.length() > idx + 1) { retVal.setParams(url.substring(idx + 1, url.length())); } break; } nextStart = idx + 1; } } return retVal; } } public static String unescape(String theString) { if (theString == null) { return null; } for (int i = 0; i < theString.length(); i++) { char nextChar = theString.charAt(i); if (nextChar == '%' || nextChar == '+') { try { return URLDecoder.decode(theString, "UTF-8"); } catch (UnsupportedEncodingException e) { throw new Error("UTF-8 not supported, this shouldn't happen", e); } } } return theString; } public static class UrlParts { private String myParams; private String myResourceId; private String myResourceType; private String myVersionId; public String getParams() { return myParams; } public String getResourceId() { return myResourceId; } public String getResourceType() { return myResourceType; } public String getVersionId() { return myVersionId; } public void setParams(String theParams) { myParams = theParams; } public void setResourceId(String theResourceId) { myResourceId = theResourceId; } public void setResourceType(String theResourceType) { myResourceType = theResourceType; } public void setVersionId(String theVersionId) { myVersionId = theVersionId; } } }