Java tutorial
package ca.uhn.fhir.rest.server.servlet; /* * #%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 static org.apache.commons.lang3.StringUtils.isNotBlank; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.Reader; import java.nio.charset.Charset; import java.util.Collections; import java.util.Enumeration; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import java.util.zip.GZIPInputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.io.IOUtils; import org.apache.http.entity.ContentType; import ca.uhn.fhir.context.ConfigurationException; import ca.uhn.fhir.rest.api.RequestTypeEnum; import ca.uhn.fhir.rest.method.BaseMethodBinding; import ca.uhn.fhir.rest.method.BaseMethodBinding.IRequestReader; import ca.uhn.fhir.rest.method.RequestDetails; import ca.uhn.fhir.rest.server.Constants; import ca.uhn.fhir.rest.server.RestfulServer; import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException; public class ServletRequestDetails extends RequestDetails { private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(ServletRequestDetails.class); /** * @see BaseMethodBinding#loadRequestContents(RequestDetails) */ private static volatile IRequestReader ourRequestReader; private RestfulServer myServer; private HttpServletRequest myServletRequest; private HttpServletResponse myServletResponse; private byte[] requestContents; public ServletRequestDetails() { super(); setResponse(new ServletRestfulResponse(this)); } @Override protected byte[] getByteStreamRequestContents() { /* * This is weird, but this class is used both in clients and in servers, and we want to avoid needing to depend on * servlet-api in clients since there is no point. So we dynamically load a class that does the servlet processing * in servers. Down the road it may make sense to just split the method binding classes into server and client * versions, but this isn't actually a huge deal I don't think. */ IRequestReader reader = ourRequestReader; if (reader == null) { try { Class.forName("javax.servlet.ServletInputStream"); String className = BaseMethodBinding.class.getName() + "$" + "ActiveRequestReader"; try { reader = (IRequestReader) Class.forName(className).newInstance(); } catch (Exception e1) { throw new ConfigurationException("Failed to instantiate class " + className, e1); } } catch (ClassNotFoundException e) { String className = BaseMethodBinding.class.getName() + "$" + "InactiveRequestReader"; try { reader = (IRequestReader) Class.forName(className).newInstance(); } catch (Exception e1) { throw new ConfigurationException("Failed to instantiate class " + className, e1); } } ourRequestReader = reader; } try { InputStream inputStream = reader.getInputStream(this); requestContents = IOUtils.toByteArray(inputStream); if (myServer.isUncompressIncomingContents()) { String contentEncoding = myServletRequest.getHeader(Constants.HEADER_CONTENT_ENCODING); if ("gzip".equals(contentEncoding)) { ourLog.debug("Uncompressing (GZip) incoming content"); if (requestContents.length > 0) { GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(requestContents)); requestContents = IOUtils.toByteArray(gis); } } } return requestContents; } catch (IOException e) { ourLog.error("Could not load request resource", e); throw new InvalidRequestException(String.format("Could not load request resource: %s", e.getMessage())); } } @Override public String getHeader(String name) { return getServletRequest().getHeader(name); } @Override public List<String> getHeaders(String name) { Enumeration<String> headers = getServletRequest().getHeaders(name); return headers == null ? Collections.<String>emptyList() : Collections.list(getServletRequest().getHeaders(name)); } @Override public InputStream getInputStream() throws IOException { return getServletRequest().getInputStream(); } @Override public Reader getReader() throws IOException { return getServletRequest().getReader(); } @Override public RestfulServer getServer() { return myServer; } @Override public String getServerBaseForRequest() { return getServer().getServerBaseForRequest(getServletRequest()); } public HttpServletRequest getServletRequest() { return myServletRequest; } public HttpServletResponse getServletResponse() { return myServletResponse; } public void setServer(RestfulServer theServer) { this.myServer = theServer; } public void setServletRequest(HttpServletRequest myServletRequest) { this.myServletRequest = myServletRequest; } public void setServletResponse(HttpServletResponse myServletResponse) { this.myServletResponse = myServletResponse; } public static RequestDetails withResourceAndParams(String theResourceName, RequestTypeEnum theRequestType, Set<String> theParamNames) { RequestDetails retVal = new ServletRequestDetails(); retVal.setResourceName(theResourceName); retVal.setRequestType(theRequestType); Map<String, String[]> paramNames = new HashMap<String, String[]>(); for (String next : theParamNames) { paramNames.put(next, new String[0]); } retVal.setParameters(paramNames); return retVal; } @Override public Charset getCharset() { String ct = getHeader(Constants.HEADER_CONTENT_TYPE); Charset charset = null; if (isNotBlank(ct)) { ContentType parsedCt = ContentType.parse(ct); charset = parsedCt.getCharset(); } return charset; } }