package com.kfit.demo1.bean;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

/**

 * 创建了一个实体类。

 *

 * 如何持久化呢？

 *

 * 1、使用@Entity进行实体类的持久化操作，当JPA检测到我们的实体类当中有

 *

 * @Entity 注解的时候，会在数据库中生成对应的表结构信息。

 *

 *

 * 如何指定主键以及主键的生成策略？

 *

 * 2、使用@Id指定主键.

 *

 */

@Entity

public class Cat {

    /**

     * 使用@Id指定主键.

     *

     * 使用代码@GeneratedValue(strategy=GenerationType.AUTO)

     * 指定主键的生成策略，mysql默认的是自增长。

     *

     */

    @Id @GeneratedValue(strategy=GenerationType.AUTO)

    private int id;//主键.

    private String catName;//姓名. cat_name

    private int catAge;//年龄. cat_age;

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getCatName() {

        return catName;

    }

    public void setCatName(String catName) {

        this.catName = catName;

    }

    public int getCatAge() {

        return catAge;

    }

    public void setCatAge(int catAge) {

        this.catAge = catAge;

    }

}

package com.kfit.demo1.dao;

import javax.annotation.Resource;

import org.springframework.jdbc.core.BeanPropertyRowMapper;

import org.springframework.jdbc.core.JdbcTemplate;

import org.springframework.jdbc.core.RowMapper;

import org.springframework.stereotype.Repository;

import com.kfit.demo1.bean.Cat;

/**

 * 使用@Repository注解，标注这是一个持久化操作对象.

 */

@Repository

public class CatDao {

    @Resource

    private JdbcTemplate jdbcTemplate;

    public Cat selectByCatName(String catName){

        /**

         * 1、定义一个Sql语句；

         * 2、定义一个RowMapper.

         * 3、执行查询方法.

         */

        String sql = "select *from cat where cat_name=?";

        RowMapper<Cat> rowMapper = new BeanPropertyRowMapper<>(Cat.class);

        Cat cat = jdbcTemplate.queryForObject(sql, new Object[]{catName}, rowMapper);

        return cat;

    }

}

package com.kfit.demo1.repository;

import org.springframework.data.repository.CrudRepository;

import com.kfit.demo1.bean.Cat;

/**

 * Repository -- 是接口 ，不是class.

 */

public interface CatRepository extends CrudRepository<Cat, Integer>{

}

package com.kfit.demo1.repository;

import org.springframework.data.jpa.repository.Query;

import org.springframework.data.repository.PagingAndSortingRepository;

import org.springframework.data.repository.query.Param;

import com.kfit.demo1.bean.Cat;

public interface Cat2Repository extends PagingAndSortingRepository<Cat, Integer>{

    /**

     * 1/ 查询方法 以 get | find | read 开头.

     * 2/ 涉及查询条件时，条件的属性用条件关键字连接，要注意的是条件属性以首字母大写。

     */

    //根据catName进行查询 : 根据catName进行查询.

    public Cat findByCatName(String catName);

    /**

     * 如何编写JPQL语句，

     * Hibernate  -- HQL语句.

     * JPQL 语句 和HQL语句是类似的.

     */

    @Query("from Cat where catName=:cn")

    public Cat findMyCatName(@Param("cn")String catName);

}

package com.kfit.demo1.service;

import javax.annotation.Resource;

import javax.transaction.Transactional;

import org.springframework.stereotype.Service;

import com.kfit.demo1.bean.Cat;

import com.kfit.demo1.repository.CatRepository;

import com.kfit.demo1.dao.CatDao;

import com.kfit.demo1.repository.Cat2Repository;

@Service

public class CatService {

    @Resource

    private CatRepository catRepository;

    @Resource

    private Cat2Repository cat2Repository;

    @Resource

    private CatDao catDao;

    /**

     * save,update ,delete 方法需要绑定事务.

     *

     * 使用@Transactional进行事务的绑定.

     *

     * @param cat

     */

    //保存数据.

    @Transactional

    public void save(Cat cat){

        catRepository.save(cat);

    }

    //删除数据》

    @Transactional

    public void delete(int id){

        catRepository.delete(id);

    }

    //查询数据.

    public Iterable<Cat> getAll(){

        return catRepository.findAll();

    }

    public Cat findByCatName(String catName){

        return cat2Repository.findByCatName(catName);

    }

    public Cat findByCatName2(String catName){

        return cat2Repository.findMyCatName(catName);

    }

    public Cat selectByCatName(String catName){

        return catDao.selectByCatName(catName);

    }

}

package com.kfit.demo1.controller;

import javax.annotation.Resource;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import com.kfit.demo1.bean.Cat;

import com.kfit.demo1.service.CatService;

@RestController

@RequestMapping("/cat")

public class CatController {

    @Resource

    private CatService catService;

    @RequestMapping("/save")

    public String save(){

        Cat cat = new Cat();

        cat.setCatName("jack");

        cat.setCatAge(3);

        catService.save(cat);

        return "save ok.";

    }

    @RequestMapping("/delete")

    public String delete(){

        catService.delete(1);

        return "delete ok";

    }

    @RequestMapping("/getAll")

    public Iterable<Cat> getAll(){

        return catService.getAll();

    }

    @RequestMapping("/findByCatName")

    public Cat findByCatName(String catName){

        return catService.findByCatName(catName);

    }

    @RequestMapping("/findByCatName2")

    public Cat findByCatName2(String catName){

        System.out.println("CatController.findByCatName2()");

        return catService.findByCatName2(catName);

    }

    @RequestMapping("/selectByCatName")

    public Cat selectByCatName(String catName){

        return catService.selectByCatName(catName);

    }

}