Spring Boot jpa Service层代码实例

这篇文章主要介绍了Spring Boot jpa Service层代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

package com.fei.service.impl;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;

import com.fei.NotFoundException;
import com.fei.po.Blog;
import com.fei.po.Type;
import com.fei.repository.BlogRepository;
import com.fei.service.BlogService;


@Service
public class BlogServiceImpl implements BlogService {

  @Autowired
  private BlogRepository blogRepository;

  
  @Override
  public Blog getBlog(Long id) {
    return blogRepository.findById(id).get();
  }

  
  @Override
  public Page listBlog(Pageable pageable, Blog blog) {
    return blogRepository.findAll(new Specification() {

      @Override
      public Predicate toPredicate(Root root, CriteriaQuery cq, CriteriaBuilder cb) {
 List predicates = new ArrayList<>();

 String title = blog.getTitle();
 if (!"".equals(title) && title != null) {
   predicates.add(cb.like(root.get("title"), "%" + title + "%"));
 }

 Long id = blog.getType().getId();
 if (id != null) {
   predicates.add(cb.equal(root.get("type").get("id"), id));
 }

 boolean isRecommend = blog.isRecommend();
 if (isRecommend) {
   predicates.add(cb.equal(root.get("recommend"), isRecommend));
 }

 cq.where(predicates.toArray(new Predicate[predicates.size()]));
 return null;
      }
    }, pageable);
  }

  
  @Override
  public Blog saveBlog(Blog blog) {
    return blogRepository.save(blog);
  }

  
  @Override
  public Blog updateBlog(Long id, Blog blog) {
    Blog b = blogRepository.findById(id).get();
    if (b == null) {
      throw new NotFoundException("你要更新的博客不存在！");
    }

    BeanUtils.copyProperties(b, blog);
    return blogRepository.save(blog);
  }

  
  @Override
  public void deleteBlog(Long id) {
    blogRepository.deleteById(id);
  }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。