Java tutorial
/* * Copyright 2015 MV Informtica. * * 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 br.com.mv.modulo.web; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.util.Arrays; import javax.servlet.http.HttpServletRequest; import javax.validation.Valid; import org.apache.commons.lang3.StringUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.dao.DataIntegrityViolationException; import org.springframework.data.domain.Page; import org.springframework.data.domain.PageRequest; import org.springframework.data.domain.Pageable; import org.springframework.data.domain.Sort; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.support.SessionStatus; import org.springframework.web.servlet.mvc.support.RedirectAttributes; import br.com.mv.modulo.business.GenericCrudBusiness; import br.com.mv.modulo.exception.GenericMessages; import br.com.mv.modulo.model.type.EnumTipoMensagem; import br.com.mv.modulo.repository.GenericCrudRepository; import lombok.extern.slf4j.Slf4j; @Slf4j public abstract class GenericCrudController<T> { protected Page<T> page; protected final GenericMessages genericMessages; protected final GenericCrudBusiness<T, GenericCrudRepository<T>> genericCrudBusiness; private static final int DEFAULT_INITIAL_PAGINATION_PAGE = 0; private static final int DEFAULT_PAGINATION_SIZE = 7; private Type type = Arrays .stream(((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()).findFirst() .get(); private Class<?> clazz = (Class<?>) type; @Autowired @SuppressWarnings({ "rawtypes", "unchecked" }) public GenericCrudController(GenericMessages genericMessages, GenericCrudBusiness genericCrudBusiness) { this.genericMessages = genericMessages; this.genericCrudBusiness = genericCrudBusiness; } @RequestMapping(value = { "/", "/list" }, method = RequestMethod.GET) public String tolist(Model model) { instantiateModel(model); page = null; model.addAttribute("page", page); return getListPageName(); } @RequestMapping(value = "/list", method = RequestMethod.POST) public String findModel(@ModelAttribute T t, Model model) { listModel(t, DEFAULT_INITIAL_PAGINATION_PAGE, DEFAULT_PAGINATION_SIZE, model); return getListPageName(); } @RequestMapping(value = "/listPaginated", method = RequestMethod.GET) public String findModelPaginated(@ModelAttribute T t, @RequestParam(value = "page", defaultValue = "") Integer page, @RequestParam(value = "size", defaultValue = "") Integer size, @RequestParam(value = "idToRender", defaultValue = "") String idToRender, Model model, HttpServletRequest request) { listModel(t, page, size, model); if (isAjax(request)) { return getListPageName() + " :: #" + idToRender; } else { return getListPageName(); } } protected boolean isAjax(HttpServletRequest request) { String header = request.getHeader("x-requested-with"); return header != null && "XMLHttpRequest".equals(header); } private void listModel(T t, Integer page, Integer size, Model model) { this.page = genericCrudBusiness.listModel(t, getPageable(page, size)); model.addAttribute("page", this.page); model.addAttribute(getModelName(), t); } @RequestMapping(value = "/new", method = RequestMethod.GET) public String toNewForm(Model model) { instantiateModel(model); return getFormPageName(); } @RequestMapping(value = "/delete", method = RequestMethod.GET) public String remove(@RequestParam(value = "id", required = true) Long id, RedirectAttributes redirectAttrs) { try { genericCrudBusiness.delete(id); redirectAttrs.addFlashAttribute(EnumTipoMensagem.SUCESSO.getDescricao(), genericMessages.getDeleteSuccess()); } catch (IllegalArgumentException e) { redirectAttrs.addFlashAttribute(EnumTipoMensagem.ERRO.getDescricao(), genericMessages.getNotFound()); log.trace("No foi encontrado:", e); } catch (Exception e) { redirectAttrs.addFlashAttribute(EnumTipoMensagem.ERRO.getDescricao(), e.getMessage()); log.error("Erro ao salvar:", e); } return getReturnToListURL(); } @RequestMapping(value = "/edit", method = RequestMethod.GET) public String toEditForm(@RequestParam(value = "id", required = true) T t, Model model) { model.addAttribute(getModelName(), t); return getFormPageName(); } @RequestMapping(value = "/save", method = RequestMethod.POST) public String save(@ModelAttribute @Valid T t, final BindingResult bindingResult, RedirectAttributes redirectAttrs, Model model, SessionStatus status) { if (bindingResult.hasErrors()) { model.addAttribute("org.springframework.validation.BindingResult.strategy", bindingResult); model.addAttribute(getModelName(), t); return getFormPageName(); } else { try { genericCrudBusiness.save(t); status.setComplete(); redirectAttrs.addFlashAttribute(EnumTipoMensagem.SUCESSO.getDescricao(), genericMessages.getSaveSuccess()); } catch (DataIntegrityViolationException e) { redirectAttrs.addFlashAttribute(EnumTipoMensagem.ERRO.getDescricao(), e.getMessage()); log.trace("Erro de integridade:", e); } catch (Exception e) { redirectAttrs.addFlashAttribute(EnumTipoMensagem.ERRO.getDescricao(), e.getMessage()); log.error("Erro ao salvar:", e); } } return getReturnToListURL(); } protected String getReturnToListURL() { return "redirect:/" + getModelName() + "/returnToList"; } private String getModelName() { return StringUtils.uncapitalize(clazz.getSimpleName()); } @RequestMapping(value = { "/returnToList" }, method = RequestMethod.GET) public String returnToListAndFindAll(Model model) { this.page = genericCrudBusiness.listModel(createNewObject(), getPageable(DEFAULT_INITIAL_PAGINATION_PAGE, DEFAULT_PAGINATION_SIZE)); instantiateModel(model); model.addAttribute("page", this.page); return getListPageName(); } protected void instantiateModel(Model model) { model.addAttribute(getModelName(), createNewObject()); } @SuppressWarnings("unchecked") private T createNewObject() { T t = null; try { t = (T) clazz.newInstance(); } catch (InstantiationException | IllegalAccessException e) { log.error("Erro ao instanciar um objeto:", e); } return t; } protected Pageable getPageable(Integer page, Integer size) { Pageable pageable; if (StringUtils.isNotEmpty(getFieldToSortList())) { pageable = new PageRequest(page, size, Sort.DEFAULT_DIRECTION, getFieldToSortList()); } else { pageable = new PageRequest(page, size); } return pageable; } protected String getFieldToSortList() { return null; } protected int getDefaultPaginationSize() { return DEFAULT_PAGINATION_SIZE; } protected String getListPageName() { return getModelUrlMapping() + "List"; } protected String getFormPageName() { return getModelUrlMapping() + "Form"; } private String getModelUrlMapping() { return getModelName() + "/" + getModelName(); } }