Java tutorial
/** * Copyright 2010-2016 Ralph Schaer <ralphschaer@gmail.com> * * 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 ch.ralscha.extdirectspring.bean; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.LogFactory; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.context.MessageSource; import org.springframework.validation.BindingResult; import org.springframework.validation.FieldError; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.servlet.HandlerExceptionResolver; import org.springframework.web.servlet.support.RequestContextUtils; import ch.ralscha.extdirectspring.controller.Configuration; import ch.ralscha.extdirectspring.controller.RouterController; import ch.ralscha.extdirectspring.util.ExtDirectSpringUtil; /** * An utility class that helps building the response for a FORM_POST method. The response * is written directly into the {@link HttpServletResponse#getOutputStream()} with * {@link #buildAndWrite()}. */ public class ExtDirectResponseBuilder { private final ExtDirectResponse extDirectResponse; private final HttpServletRequest request; private final HttpServletResponse response; private final Map<String, Object> result; private Class<?> jsonView; /** * Creates a builder that builds and writes the response of a FORM_POST method. Sets * the successful flag to true, can be changed with the {@link #successful()} and * {@link #unsuccessful()} methods. * * @param request the current http servlet request object * @param response the current http servlet response object */ public ExtDirectResponseBuilder(HttpServletRequest request, HttpServletResponse response) { this.request = request; this.response = response; this.extDirectResponse = new ExtDirectResponse(request); this.result = new HashMap<String, Object>(); successful(); this.extDirectResponse.setResult(this.result); } /** * Creates a builder instance. * * @see #ExtDirectResponseBuilder(HttpServletRequest, HttpServletResponse) * * @param request the current http servlet request object * @param response the current http servlet response object * * @return the created builder instance */ public static ExtDirectResponseBuilder create(HttpServletRequest request, HttpServletResponse response) { return new ExtDirectResponseBuilder(request, response); } /** * Creates an "exception" response. Calls {@link ExtDirectResponse#setType(String)} * with a value of "exception". Calls {@link ExtDirectResponse#setMessage(String)} and * {@link ExtDirectResponse#setWhere(String)} according to the {@link Configuration}. * * This is a method primarily used for implementations of * {@link HandlerExceptionResolver}. * * @param exception the exception that was thrown. * @return this instance */ public ExtDirectResponseBuilder setException(Exception exception) { unsuccessful(); WebApplicationContext ctx = RequestContextUtils.findWebApplicationContext(this.request); Configuration configuration; try { configuration = ctx.getBean(Configuration.class); } catch (NoSuchBeanDefinitionException e) { configuration = new Configuration(); } this.extDirectResponse.setType("exception"); this.extDirectResponse.setMessage(configuration.getMessage(exception)); if (configuration.isSendStacktrace()) { this.extDirectResponse.setWhere(ExtDirectSpringUtil.getStackTrace(exception)); } else { this.extDirectResponse.setWhere(null); } return this; } /** * Adds an "errors" property in the response if there are any errors in the * bindingResult. Sets the success flag to false if there are errors. * * @param bindingResult * @return this instance */ public ExtDirectResponseBuilder addErrors(BindingResult bindingResult) { addErrors(null, null, bindingResult); return this; } /** * Adds an "errors" property in the response if there are any errors in the * bindingResult. Sets the success flag to false if there are errors. * * @param locale * @param messageSource * @param bindingResult * @return this instance */ public ExtDirectResponseBuilder addErrors(Locale locale, MessageSource messageSource, final BindingResult bindingResult) { if (bindingResult != null && bindingResult.hasFieldErrors()) { Map<String, List<String>> errorMap = new HashMap<String, List<String>>(); for (FieldError fieldError : bindingResult.getFieldErrors()) { String message = fieldError.getDefaultMessage(); if (messageSource != null) { Locale loc = locale != null ? locale : Locale.getDefault(); message = messageSource.getMessage(fieldError.getCode(), fieldError.getArguments(), loc); } List<String> fieldErrors = errorMap.get(fieldError.getField()); if (fieldErrors == null) { fieldErrors = new ArrayList<String>(); errorMap.put(fieldError.getField(), fieldErrors); } fieldErrors.add(message); } if (errorMap.isEmpty()) { addResultProperty("success", Boolean.TRUE); } else { addResultProperty("errors", errorMap); addResultProperty("success", Boolean.FALSE); } } return this; } /** * Add additional property to the response. * * @param key the key of the property * @param value the value of this property * @return this instance */ public ExtDirectResponseBuilder addResultProperty(String key, Object value) { this.result.put(key, value); return this; } /** * Sets success flag to true. * * @return this instance */ public ExtDirectResponseBuilder successful() { this.result.put("success", Boolean.TRUE); return this; } /** * Sets success flag to false. * * @return this instance */ public ExtDirectResponseBuilder unsuccessful() { this.result.put("success", Boolean.FALSE); return this; } /** * Sets success flag to the provided parameter. * * @param flag the new success value * @return this instance */ public ExtDirectResponseBuilder setSuccess(boolean flag) { this.result.put("success", flag); return this; } /** * Sets a specific JSON View (filter) that Jackson uses to serialize the response. * * @param jsonView */ public void setJsonView(Class<?> jsonView) { this.jsonView = jsonView; } /** * Builds and writes the response into the OutputStream of {@link HttpServletResponse} * . This methods has to be called at the end of a FORM_POST method. */ public void buildAndWrite() { try { RouterController routerController = RequestContextUtils.findWebApplicationContext(this.request) .getBean(RouterController.class); routerController.writeJsonResponse(this.request, this.response, this.extDirectResponse, this.jsonView); } catch (IOException e) { LogFactory.getLog(getClass()).error("buildAndWrite", e); throw new RuntimeException(e); } } }