目录

• 新闻、分类、标签管理
• 删除功能
• 更新功能
• 模糊搜索
• 局部刷新实现分页

新闻、分类、标签管理

删除功能

1.修改NewService接口；
NewServicer中添加：

void deleteById(Long id);

2.修改NewServiceImpl类；
NewServiceImpl中添加：

@Overridepublic void deleteById(Long id) {newsRepository.deleteById(id);}

3.修改NewControllerr类；
NewController中添加：

@GetMapping("/news/{id}/delete")public String delete(@PathVariable Long id, RedirectAttributes attributes) {newsService.deleteById(id);attributes.addFlashAttribute("message", "删除成功");return "redirect:/admin/news";}

Test
1.进入新闻管理界面，点击删除按钮；

更新功能

1.修改NewService接口；
NewServicer中添加：

News updateNews(Long id, News news);

2.修改NewServiceImpl类；
NewServiceImpl中添加：

@Overridepublic News updateNews(Long id, News news) {News n = newsRepository.getOne(id);if (n == null) {System.out.println("不存在该新闻");return null;}news.setUpdateTime(new Date());return newsRepository.save(news);}

3.修改NewControllerr类；
NewController中添加：

@GetMapping("news/{id}/toUpdate")public String toUpdate(@PathVariable Long id, Model model) {News news = newsService.getNewsById(id);news.init(); // tag的list集合 转换成了 对应的字符串model.addAttribute("news", news);model.addAttribute("types", typeService.listType());model.addAttribute("tags", tagService.listTag());return "admin/news-input";}

Test

模糊搜索

1.创建新实体类NewQuery

package com.zhongruan.entity;import javax.persistence.Entity;import javax.persistence.Table;/*** @author serena**/@Entity@Table(name = "t_query")public class NewQuery {private String title;private Long typeId;private boolean recommend;public NewQuery() {}public NewQuery(String title, Long typeId, boolean recommend) {this.title = title;this.typeId = typeId;this.recommend = recommend;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public Long getTypeId() {return typeId;}public void setTypeId(Long typeId) {this.typeId = typeId;}public boolean isRecommend() {return recommend;}public void setRecommend(boolean recommend) {this.recommend = recommend;}@Overridepublic String toString() {return "NewQuery{" +"title='" + title + '\'' +", typeId=" + typeId +", recommend=" + recommend +'}';}}

2.修改NewService接口；
NewServicer中添加：

News getNewsById(Long id);

3.修改newServiceImpl类

@Overridepublic News getNewsById(Long id) {return newsRepository.getOne(id);}

局部刷新实现分页

2.修改NewService接口；
NewServicer中添加：

// 分页的全查Page<News> listNews(Pageable pageable);// 带查询条件的分页全查Page<News> listNews(Pageable pageable, NewQuery newQuery);

3.修改newServiceImpl类

@Overridepublic Page<News> listNews(Pageable pageable, NewQuery newQuery) {return newsRepository.findAll(new Specification() {@Overridepublic Predicate toPredicate(Root root, CriteriaQuery cq, CriteriaBuilder cb) {// root 数据库中的字段名// CriteriaBuilder 构建查询条件// CriteriaQuery 执行查询条件// 1. 创建集合 存储查询条件List<Predicate> list = new ArrayList<>();// 2. 添加查询条件if (!"".equals(newQuery.getTitle()) && newQuery.getTitle() != null) {// 当title 有值时 项目list集合中存储查询条件 select * from t_user where name like %zhang%list.add(cb.like(root.<String>get("title"), "%" + newQuery.getTitle() + "%"));}if (newQuery.getTypeId() != null) {list.add(cb.equal(root.<Long>get("type").get("id"), newQuery.getTypeId()));}if (newQuery.isRecommend()) {list.add(cb.equal(root.<Boolean>get("recommend"), newQuery.isRecommend()));}// 3. 执行查询cq.where(list.toArray(new Predicate[list.size()]));return null;}},pageable);}

test