Java tutorial
/* * Copyright (c) WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. licenses this file to you 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.wso2.carbon.mss.internal.router; import com.google.common.base.Charsets; import com.google.common.base.Preconditions; import io.netty.handler.codec.http.FullHttpRequest; import io.netty.handler.codec.http.HttpRequest; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.QueryStringDecoder; import org.wso2.carbon.mss.HttpResponder; import org.wso2.carbon.mss.HttpStreamer; import org.wso2.carbon.mss.internal.router.beanconversion.BeanConverter; import java.lang.annotation.Annotation; import java.lang.reflect.Type; import java.util.Arrays; import java.util.List; import java.util.Map; import javax.ws.rs.HeaderParam; import javax.ws.rs.PathParam; import javax.ws.rs.QueryParam; import javax.ws.rs.core.Context; /** * This class is responsible for processing the HttpResourceModel * when a HTTP request arrives. */ public class HttpResourceModelProcessor { private final HttpResourceModel httpResourceModel; private HttpStreamer httpStreamer; public HttpResourceModelProcessor(HttpResourceModel httpResourceModel) { this.httpResourceModel = httpResourceModel; } /** * Handle http Request. * * @param request HttpRequest to be handled. * @param responder HttpResponder to write the response. * @param groupValues Values needed for the invocation. * @param contentType Content types * @param acceptTypes Accept types * @return HttpMethodInfo * @throws HandlerException If an error occurs */ @SuppressWarnings("unchecked") public HttpMethodInfo buildHttpMethodInfo(HttpRequest request, HttpResponder responder, Map<String, String> groupValues, String contentType, List<String> acceptTypes) throws HandlerException { //TODO: Refactor group values. try { if (httpResourceModel.getHttpMethod().contains(request.getMethod())) { //Setup args for reflection call List<HttpResourceModel.ParameterInfo<?>> paramInfoList = httpResourceModel.getParamInfoList(); List<String> producesMediaTypes = httpResourceModel.getProducesMediaTypes(); Object[] args = new Object[paramInfoList.size()]; String acceptType = "*/*"; if (!producesMediaTypes.contains("*/*") && acceptTypes != null) { acceptType = (acceptTypes.contains("*/*")) ? producesMediaTypes.get(0) : producesMediaTypes.stream().filter(acceptTypes::contains).findFirst().get(); } int idx = 0; for (HttpResourceModel.ParameterInfo<?> paramInfo : paramInfoList) { if (paramInfo.getAnnotation() != null) { Class<? extends Annotation> annotationType = paramInfo.getAnnotation().annotationType(); if (PathParam.class.isAssignableFrom(annotationType)) { args[idx] = getPathParamValue((HttpResourceModel.ParameterInfo<String>) paramInfo, groupValues); } else if (QueryParam.class.isAssignableFrom(annotationType)) { args[idx] = getQueryParamValue( (HttpResourceModel.ParameterInfo<List<String>>) paramInfo, request.getUri()); } else if (HeaderParam.class.isAssignableFrom(annotationType)) { args[idx] = getHeaderParamValue( (HttpResourceModel.ParameterInfo<List<String>>) paramInfo, request); } else if (Context.class.isAssignableFrom(annotationType)) { args[idx] = getContextParamValue((HttpResourceModel.ParameterInfo<Object>) paramInfo, request, responder); } } else if (request instanceof FullHttpRequest) { // If an annotation is not present the parameter is considered a // request body data parameter String content = ((FullHttpRequest) request).content().toString(Charsets.UTF_8); Type paramType = paramInfo.getParameterType(); args[idx] = BeanConverter.instance((contentType != null) ? contentType : "*/*") .toObject(content, paramType); } idx++; } if (httpStreamer == null) { return new HttpMethodInfo(httpResourceModel.getMethod(), httpResourceModel.getHttpHandler(), request, responder, args, httpResourceModel.getExceptionHandler(), acceptType); } else { return new HttpMethodInfo(httpResourceModel.getMethod(), httpResourceModel.getHttpHandler(), request, responder, args, httpResourceModel.getExceptionHandler(), acceptType, httpStreamer); } } else { //Found a matching resource but could not find the right HttpMethod so return 405 throw new HandlerException(HttpResponseStatus.METHOD_NOT_ALLOWED, String.format("Problem accessing: %s. Reason: Method Not Allowed", request.getUri())); } } catch (Throwable e) { throw new HandlerException(HttpResponseStatus.INTERNAL_SERVER_ERROR, String.format("Error in executing request: %s %s", request.getMethod(), request.getUri()), e); } } @SuppressWarnings("unchecked") private Object getContextParamValue(HttpResourceModel.ParameterInfo<Object> paramInfo, HttpRequest request, HttpResponder responder) { Type paramType = paramInfo.getParameterType(); Object value = null; if (((Class) paramType).isAssignableFrom(HttpRequest.class)) { value = request; } else if (((Class) paramType).isAssignableFrom(HttpResponder.class)) { value = responder; } else if (((Class) paramType).isAssignableFrom(HttpStreamer.class)) { if (httpStreamer == null) { httpStreamer = new HttpStreamer(); } value = httpStreamer; } Preconditions.checkArgument(value != null, "Could not resolve parameter %s", paramType.getTypeName()); return value; } @SuppressWarnings("unchecked") private Object getPathParamValue(HttpResourceModel.ParameterInfo<String> info, Map<String, String> groupValues) { PathParam pathParam = info.getAnnotation(); String value = groupValues.get(pathParam.value()); Preconditions.checkArgument(value != null, "Could not resolve value for parameter %s", pathParam.value()); if (value == null) { String defaultVal = info.getDefaultVal(); if (defaultVal != null) { value = defaultVal; } } return info.convert(value); } @SuppressWarnings("unchecked") private Object getQueryParamValue(HttpResourceModel.ParameterInfo<List<String>> info, String uri) { QueryParam queryParam = info.getAnnotation(); List<String> values = new QueryStringDecoder(uri).parameters().get(queryParam.value()); if (values == null || values.isEmpty()) { String defaultVal = info.getDefaultVal(); if (defaultVal != null) { values = Arrays.asList(defaultVal); } } return info.convert(values); } @SuppressWarnings("unchecked") private Object getHeaderParamValue(HttpResourceModel.ParameterInfo<List<String>> info, HttpRequest request) { HeaderParam headerParam = info.getAnnotation(); String headerName = headerParam.value(); List<String> headers = request.headers().getAll(headerName); if (headers == null || headers.isEmpty()) { String defaultVal = info.getDefaultVal(); if (defaultVal != null) { headers = Arrays.asList(defaultVal); } } return info.convert(headers); } }