Java tutorial
/* * Copyright (c) 2013, Inversoft Inc., All Rights Reserved * * 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. */ package org.primeframework.mvc.content.json; import javax.servlet.http.HttpServletRequest; import java.io.IOException; import java.util.List; import org.apache.commons.io.IOUtils; import org.primeframework.mvc.action.ActionInvocation; import org.primeframework.mvc.action.ActionInvocationStore; import org.primeframework.mvc.action.config.ActionConfiguration; import org.primeframework.mvc.content.ContentHandler; import org.primeframework.mvc.message.MessageStore; import org.primeframework.mvc.message.MessageType; import org.primeframework.mvc.message.SimpleFieldMessage; import org.primeframework.mvc.message.SimpleMessage; import org.primeframework.mvc.message.l10n.MessageProvider; import org.primeframework.mvc.parameter.el.ExpressionEvaluator; import org.primeframework.mvc.validation.ValidationException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.exc.InvalidFormatException; import com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException; import com.google.inject.Inject; /** * Uses the Jackson JSON processor to marshall JSON into Java objects and set them into the action. * * @author Brian Pontarelli */ public class JacksonContentHandler implements ContentHandler { private static final Logger logger = LoggerFactory.getLogger(JacksonContentHandler.class); private final ExpressionEvaluator expressionEvaluator; private final MessageProvider messageProvider; private final MessageStore messageStore; private final ObjectMapper objectMapper; private final HttpServletRequest request; private final ActionInvocationStore store; @Inject public JacksonContentHandler(HttpServletRequest request, ActionInvocationStore store, ObjectMapper objectMapper, ExpressionEvaluator expressionEvaluator, MessageProvider messageProvider, MessageStore messageStore) { this.request = request; this.store = store; this.objectMapper = objectMapper; this.expressionEvaluator = expressionEvaluator; this.messageProvider = messageProvider; this.messageStore = messageStore; } @Override public void handle() throws IOException { ActionInvocation current = store.getCurrent(); Object action = current.action; if (action == null) { return; } ActionConfiguration config = current.configuration; if (!config.additionalConfiguration.containsKey(JacksonActionConfiguration.class)) { return; } int contentLength = request.getContentLength(); if (contentLength == 0) { return; } // Process JSON and set into the object JacksonActionConfiguration jacksonConfiguration = (JacksonActionConfiguration) config.additionalConfiguration .get(JacksonActionConfiguration.class); if (jacksonConfiguration.requestMember != null) { try { Object jsonObject; if (logger.isDebugEnabled()) { final String req = IOUtils.toString(request.getInputStream(), "UTF-8"); logger.debug("Request: (" + request.getMethod() + " " + request.getRequestURI() + ") " + req); jsonObject = objectMapper.reader(jacksonConfiguration.requestMemberType).readValue(req); } else { jsonObject = objectMapper.reader(jacksonConfiguration.requestMemberType) .readValue(request.getInputStream()); } expressionEvaluator.setValue(jacksonConfiguration.requestMember, action, jsonObject); } catch (InvalidFormatException e) { logger.debug("Error parsing JSON request", e); addFieldError(e); throw new ValidationException(e); } catch (UnrecognizedPropertyException e) { logger.debug("Error parsing JSON request", e); String field = buildField(e); messageStore.add(new SimpleMessage(MessageType.ERROR, "[unrecognizedProperty]", messageProvider.getMessage("[unrecognizedProperty]", field, e.getMessage()))); throw new ValidationException(e); } catch (JsonMappingException e) { logger.debug("Error parsing JSON request", e); if (!(e.getCause() instanceof JsonParseException)) { addFieldError(e); } else { messageStore.add(new SimpleMessage(MessageType.ERROR, "[couldNotParseJSON]", messageProvider.getMessage("[couldNotParseJSON]", e.getMessage()))); } throw new ValidationException(e); } catch (JsonProcessingException e) { logger.debug("Error parsing JSON request", e); messageStore.add(new SimpleMessage(MessageType.ERROR, "[couldNotParseJSON]", messageProvider.getMessage("[couldNotParseJSON]", e.getMessage()))); throw new ValidationException(e); } } } /** * Adds a field error using the information stored in the JsonMappingException. * * @param e The exception. */ private void addFieldError(JsonMappingException e) { // Build the path so we can make the error String field = buildField(e); String code = "[couldNotConvert]" + field; messageStore.add(new SimpleFieldMessage(MessageType.ERROR, field, code, messageProvider.getMessage(code, e.getMessage()))); } private String buildField(JsonMappingException e) { StringBuilder fieldBuilder = new StringBuilder(); List<JsonMappingException.Reference> references = e.getPath(); for (JsonMappingException.Reference reference : references) { String fieldName = reference.getFieldName(); if (fieldName == null) { continue; } if (fieldBuilder.length() > 0) { fieldBuilder.append("."); } fieldBuilder.append(fieldName); } return fieldBuilder.toString(); } }