Java tutorial
package ca.uhn.fhir.rest.server.interceptor; import static org.apache.commons.lang3.StringUtils.isBlank; import static org.apache.commons.lang3.StringUtils.isNotBlank; /* * #%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% */ import java.io.IOException; import java.util.Date; import java.util.Map; import java.util.Set; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang3.StringEscapeUtils; import org.hl7.fhir.instance.model.api.IBaseResource; import ca.uhn.fhir.parser.IParser; import ca.uhn.fhir.rest.api.RequestTypeEnum; import ca.uhn.fhir.rest.method.RequestDetails; import ca.uhn.fhir.rest.server.Constants; import ca.uhn.fhir.rest.server.EncodingEnum; import ca.uhn.fhir.rest.server.RestfulServer; import ca.uhn.fhir.rest.server.RestfulServerUtils; import ca.uhn.fhir.rest.server.exceptions.AuthenticationException; import ca.uhn.fhir.rest.server.exceptions.BaseServerResponseException; import ca.uhn.fhir.rest.server.exceptions.InternalErrorException; import ca.uhn.fhir.util.UrlUtil; /** * This interceptor detects when a request is coming from a browser, and automatically returns a response with syntax * highlighted (coloured) HTML for the response instead of just returning raw XML/JSON. * * @since 1.0 */ public class ResponseHighlighterInterceptor extends InterceptorAdapter { private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory .getLogger(ResponseHighlighterInterceptor.class); private static final String[] PARAM_FORMAT_VALUE_JSON = new String[] { Constants.FORMAT_JSON }; private static final String[] PARAM_FORMAT_VALUE_XML = new String[] { Constants.FORMAT_XML }; /** * TODO: As of HAPI 1.6 (2016-06-10) this parameter has been replaced with simply * requesting _format=json or xml so eventually this parameter should be removed */ public static final String PARAM_RAW = "_raw"; public static final String PARAM_RAW_TRUE = "true"; public static final String PARAM_TRUE = "true"; private String format(String theResultBody, EncodingEnum theEncodingEnum) { String str = StringEscapeUtils.escapeHtml4(theResultBody); if (str == null || theEncodingEnum == null) { return str; } StringBuilder b = new StringBuilder(); if (theEncodingEnum == EncodingEnum.JSON) { boolean inValue = false; boolean inQuote = false; for (int i = 0; i < str.length(); i++) { char prevChar = (i > 0) ? str.charAt(i - 1) : ' '; char nextChar = str.charAt(i); char nextChar2 = (i + 1) < str.length() ? str.charAt(i + 1) : ' '; char nextChar3 = (i + 2) < str.length() ? str.charAt(i + 2) : ' '; char nextChar4 = (i + 3) < str.length() ? str.charAt(i + 3) : ' '; char nextChar5 = (i + 4) < str.length() ? str.charAt(i + 4) : ' '; char nextChar6 = (i + 5) < str.length() ? str.charAt(i + 5) : ' '; if (inQuote) { b.append(nextChar); if (prevChar != '\\' && nextChar == '&' && nextChar2 == 'q' && nextChar3 == 'u' && nextChar4 == 'o' && nextChar5 == 't' && nextChar6 == ';') { b.append("quot;</span>"); i += 5; inQuote = false; } else if (nextChar == '\\' && nextChar2 == '"') { b.append("quot;</span>"); i += 5; inQuote = false; } } else { if (nextChar == ':') { inValue = true; b.append(nextChar); } else if (nextChar == '[' || nextChar == '{') { b.append("<span class='hlControl'>"); b.append(nextChar); b.append("</span>"); inValue = false; } else if (nextChar == '}' || nextChar == '}' || nextChar == ',') { b.append("<span class='hlControl'>"); b.append(nextChar); b.append("</span>"); inValue = false; } else if (nextChar == '&' && nextChar2 == 'q' && nextChar3 == 'u' && nextChar4 == 'o' && nextChar5 == 't' && nextChar6 == ';') { if (inValue) { b.append("<span class='hlQuot'>""); } else { b.append("<span class='hlTagName'>""); } inQuote = true; i += 5; } else if (nextChar == ':') { b.append("<span class='hlControl'>"); b.append(nextChar); b.append("</span>"); inValue = true; } else { b.append(nextChar); } } } } else { boolean inQuote = false; boolean inTag = false; for (int i = 0; i < str.length(); i++) { char nextChar = str.charAt(i); char nextChar2 = (i + 1) < str.length() ? str.charAt(i + 1) : ' '; char nextChar3 = (i + 2) < str.length() ? str.charAt(i + 2) : ' '; char nextChar4 = (i + 3) < str.length() ? str.charAt(i + 3) : ' '; char nextChar5 = (i + 4) < str.length() ? str.charAt(i + 4) : ' '; char nextChar6 = (i + 5) < str.length() ? str.charAt(i + 5) : ' '; if (inQuote) { b.append(nextChar); if (nextChar == '&' && nextChar2 == 'q' && nextChar3 == 'u' && nextChar4 == 'o' && nextChar5 == 't' && nextChar6 == ';') { b.append("quot;</span>"); i += 5; inQuote = false; } } else if (inTag) { if (nextChar == '&' && nextChar2 == 'g' && nextChar3 == 't' && nextChar4 == ';') { b.append("</span><span class='hlControl'>></span>"); inTag = false; i += 3; } else if (nextChar == ' ') { b.append("</span><span class='hlAttr'>"); b.append(nextChar); } else if (nextChar == '&' && nextChar2 == 'q' && nextChar3 == 'u' && nextChar4 == 'o' && nextChar5 == 't' && nextChar6 == ';') { b.append("<span class='hlQuot'>""); inQuote = true; i += 5; } else { b.append(nextChar); } } else { if (nextChar == '&' && nextChar2 == 'l' && nextChar3 == 't' && nextChar4 == ';') { b.append("<span class='hlControl'><</span><span class='hlTagName'>"); inTag = true; i += 3; } else { b.append(nextChar); } } } } return b.toString(); } @Override public boolean handleException(RequestDetails theRequestDetails, BaseServerResponseException theException, HttpServletRequest theServletRequest, HttpServletResponse theServletResponse) throws ServletException, IOException { /* * It's not a browser... */ Set<String> accept = RestfulServerUtils.parseAcceptHeaderAndReturnHighestRankedOptions(theServletRequest); if (!accept.contains(Constants.CT_HTML)) { return super.handleException(theRequestDetails, theException, theServletRequest, theServletResponse); } /* * It's an AJAX request, so no HTML */ String requestedWith = theServletRequest.getHeader("X-Requested-With"); if (requestedWith != null) { return super.handleException(theRequestDetails, theException, theServletRequest, theServletResponse); } /* * Not a GET */ if (theRequestDetails.getRequestType() != RequestTypeEnum.GET) { return super.handleException(theRequestDetails, theException, theServletRequest, theServletResponse); } if (theException.getOperationOutcome() == null) { return super.handleException(theRequestDetails, theException, theServletRequest, theServletResponse); } streamResponse(theRequestDetails, theServletResponse, theException.getOperationOutcome(), theServletRequest); return false; } @Override public boolean outgoingResponse(RequestDetails theRequestDetails, IBaseResource theResponseObject, HttpServletRequest theServletRequest, HttpServletResponse theServletResponse) throws AuthenticationException { /* * Request for _raw */ String[] rawParamValues = theRequestDetails.getParameters().get(PARAM_RAW); if (rawParamValues != null && rawParamValues.length > 0 && rawParamValues[0].equals(PARAM_RAW_TRUE)) { ourLog.warn( "Client is using non-standard/legacy _raw parameter - Use _format=json or _format=xml instead, as this parmameter will be removed at some point"); return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } boolean force = false; String[] formatParams = theRequestDetails.getParameters().get(Constants.PARAM_FORMAT); if (formatParams != null && formatParams.length > 0) { String formatParam = formatParams[0]; if (Constants.FORMATS_HTML.contains(formatParam)) { // this is a set force = true; } else if (Constants.FORMATS_HTML_XML.equals(formatParam)) { force = true; theRequestDetails.getParameters().put(Constants.PARAM_FORMAT, PARAM_FORMAT_VALUE_XML); } else if (Constants.FORMATS_HTML_JSON.equals(formatParam)) { force = true; theRequestDetails.getParameters().put(Constants.PARAM_FORMAT, PARAM_FORMAT_VALUE_JSON); } else { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } } /* * It's not a browser... */ Set<String> highestRankedAcceptValues = RestfulServerUtils .parseAcceptHeaderAndReturnHighestRankedOptions(theServletRequest); if (!force && highestRankedAcceptValues.contains(Constants.CT_HTML) == false) { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } /* * It's an AJAX request, so no HTML */ if (!force && isNotBlank(theServletRequest.getHeader("X-Requested-With"))) { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } /* * If the request has an Origin header, it is probably an AJAX request */ if (!force && isNotBlank(theServletRequest.getHeader(Constants.HEADER_ORIGIN))) { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } /* * Not a GET */ if (!force && theRequestDetails.getRequestType() != RequestTypeEnum.GET) { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } /* * Not binary */ if (!force && "Binary".equals(theRequestDetails.getResourceName())) { return super.outgoingResponse(theRequestDetails, theResponseObject, theServletRequest, theServletResponse); } streamResponse(theRequestDetails, theServletResponse, theResponseObject, theServletRequest); return false; } private void streamResponse(RequestDetails theRequestDetails, HttpServletResponse theServletResponse, IBaseResource resource, ServletRequest theServletRequest) { IParser p; Map<String, String[]> parameters = theRequestDetails.getParameters(); if (parameters.containsKey(Constants.PARAM_FORMAT)) { p = RestfulServerUtils.getNewParser(theRequestDetails.getServer().getFhirContext(), theRequestDetails); } else { EncodingEnum defaultResponseEncoding = theRequestDetails.getServer().getDefaultResponseEncoding(); p = defaultResponseEncoding.newParser(theRequestDetails.getServer().getFhirContext()); RestfulServerUtils.configureResponseParser(theRequestDetails, p); } // This interceptor defaults to pretty printing unless the user // has specifically requested us not to boolean prettyPrintResponse = true; String[] prettyParams = parameters.get(Constants.PARAM_PRETTY); if (prettyParams != null && prettyParams.length > 0) { if (Constants.PARAM_PRETTY_VALUE_FALSE.equals(prettyParams[0])) { prettyPrintResponse = false; } } if (prettyPrintResponse) { p.setPrettyPrint(prettyPrintResponse); } EncodingEnum encoding = p.getEncoding(); String encoded = p.encodeResourceToString(resource); theServletResponse.setContentType(Constants.CT_HTML_WITH_UTF8); StringBuilder b = new StringBuilder(); b.append("<html lang=\"en\">\n"); b.append(" <head>\n"); b.append(" <meta charset=\"utf-8\" />\n"); b.append(" <style>\n"); b.append(".hlQuot {\n"); b.append(" color: #88F;\n"); b.append("}\n"); b.append(".hlAttr {\n"); b.append(" color: #888;\n"); b.append("}\n"); b.append(".hlTagName {\n"); b.append(" color: #006699;\n"); b.append("}\n"); b.append(".hlControl {\n"); b.append(" color: #660000;\n"); b.append("}\n"); b.append(".hlText {\n"); b.append(" color: #000000;\n"); b.append("}\n"); b.append(".hlUrlBase {\n"); b.append("}"); b.append(".headersDiv {\n"); b.append(" background: #EEE;"); b.append("}"); b.append(".headerName {\n"); b.append(" color: #888;\n"); b.append(" font-family: monospace;\n"); b.append("}"); b.append(".headerValue {\n"); b.append(" color: #88F;\n"); b.append(" font-family: monospace;\n"); b.append("}"); b.append("BODY {\n"); b.append(" font-family: Arial;\n"); b.append("}"); b.append(" </style>\n"); b.append(" </head>\n"); b.append("\n"); b.append(" <body>"); b.append("<p>"); b.append("This result is being rendered in HTML for easy viewing. "); b.append("You may access this content as "); b.append("<a href=\""); b.append(createLinkHref(parameters, Constants.FORMAT_JSON)); b.append("\">Raw JSON</a> or "); b.append("<a href=\""); b.append(createLinkHref(parameters, Constants.FORMAT_XML)); b.append("\">Raw XML</a>, "); b.append(" or view this content in "); b.append("<a href=\""); b.append(createLinkHref(parameters, Constants.FORMATS_HTML_JSON)); b.append("\">HTML JSON</a> "); b.append("or "); b.append("<a href=\""); b.append(createLinkHref(parameters, Constants.FORMATS_HTML_XML)); b.append("\">HTML XML</a>."); Date startTime = (Date) theServletRequest.getAttribute(RestfulServer.REQUEST_START_TIME); if (startTime != null) { long time = System.currentTimeMillis() - startTime.getTime(); b.append(" Response generated in "); b.append(time); b.append("ms."); } b.append("</p>"); b.append("\n"); // if (isEncodeHeaders()) { // b.append("<h1>Request Headers</h1>"); // b.append("<div class=\"headersDiv\">"); // for (int next : theRequestDetails.get) // b.append("</div>"); // b.append("<h1>Response Headers</h1>"); // b.append("<div class=\"headersDiv\">"); // b.append("</div>"); // b.append("<h1>Response Body</h1>"); // } b.append("<pre>"); b.append(format(encoded, encoding)); b.append("</pre>"); b.append(" </body>"); b.append("</html>"); //@formatter:off String out = b.toString(); //@formatter:on try { theServletResponse.getWriter().append(out); theServletResponse.getWriter().close(); } catch (IOException e) { throw new InternalErrorException(e); } } private String createLinkHref(Map<String, String[]> parameters, String formatValue) { StringBuilder rawB = new StringBuilder(); for (String next : parameters.keySet()) { if (Constants.PARAM_FORMAT.equals(next)) { continue; } for (String nextValue : parameters.get(next)) { if (isBlank(nextValue)) { continue; } if (rawB.length() == 0) { rawB.append('?'); } else { rawB.append('&'); } rawB.append(UrlUtil.escape(next)); rawB.append('='); rawB.append(UrlUtil.escape(nextValue)); } } if (rawB.length() == 0) { rawB.append('?'); } else { rawB.append('&'); } rawB.append(Constants.PARAM_FORMAT).append('=').append(formatValue); String link = rawB.toString(); return link; } }