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1.JPA

自动生成数据库表，提供简单的增删改查方法

2.项目目录

3.pom.xml

   
   	
    
     4.0.0
    	
    		
     
      org.springframework.boot
     		
     
      spring-boot-starter-parent
     		
     
      2.0.3.RELEASE
     		
     	
    	
    
     com.wo
    	
    
     springboot-jpa
    	
    
     0.0.1-SNAPSHOT
    	
    
     springboot-jpa
    	
    
     Demo project for Spring Boot
    	
    		
     
      1.8
     	
    	
    		
     			
      
       org.springframework.boot
      			
      
       spring-boot-starter-web
      		
     		
     			
      
       org.springframework.boot
      			
      
       spring-boot-devtools
      			
      
       runtime
      			
      
       true
      		
     		
     			
      
       org.projectlombok
      			
      
       lombok
      			
      
       true
      		
     		
     			
      
       org.springframework.boot
      			
      
       spring-boot-starter-test
      			
      
       test
      		
     		
     			
      
       org.mybatis.spring.boot
      			
      
       mybatis-spring-boot-starter
      			
      
       1.1.1
      		
     		
     			
      
       mysql
      			
      
       mysql-connector-java
      		
     		
     		
     		
     			
      
       org.apache.tomcat.embed
      			
      
       tomcat-embed-jasper
      		
     		
     		
     			
      
       javax.servlet
      			
      
       jstl
      		
     		
     		
     			
      
       org.springframework.boot
      			
      
       spring-boot-starter-data-jpa
      		
     	
    	
    		
     			
      				
       
        org.springframework.boot
       				
       
        spring-boot-maven-plugin
       			
      		
     	
    
   

4.pojo 自动创建表

@Data//自动生成get/set等方法@Entity//标注为JPA的实体类@Table(name = "Goods")//数据库表的名称public class Goods {
       @Id    //自增的主键策略    @GeneratedValue(strategy = GenerationType.IDENTITY)    private Integer id;    //@Column(name = "goods_name")给数据库的字段起个名称    private String name;    private String info;}

5.dao 提供简单的增删改查

//JPA应用，不用写简单的增删改查public interface GoodsRespository extends JpaRepository
   
    {
   //实体类名称和主键类型    //findBy===where name=#{name}    List
    
      findByName(String name);    List
     
       findByNameAndInfo(String name,String info);}
     
    
   

提供的源码

@NoRepositoryBeanpublic interface JpaRepository
   
     extends PagingAndSortingRepository
    
     , QueryByExampleExecutor
     
       {
       List
      
        findAll();    List
       
         findAll(Sort var1);    List
        
          findAllById(Iterable
         
           var1); 
           List saveAll(Iterable var1); void flush();  S saveAndFlush(S var1); void deleteInBatch(Iterable
              
                var1); void deleteAllInBatch(); T getOne(ID var1); 
                List findAll(Example var1);  List findAll(Example var1, Sort var2);}
              
         
        
       
      
     
    
   

6.service及serviceimpl

public interface GoodsService {
       //查询所有    public List
   
     findAllGoods();    //新增    public int insertGoods(Goods goods);    //根据ID查询    public Goods findById(int id);    //根据name查询    public List
    
      findByName(String name);    //根据ID删除    public int delete(Map map);    //根据name和info查询    public List
     
       findByNameAndInfo(Map map);}
     
    
   

@Servicepublic class GoodsServiceImpl implements GoodsService{
       @Autowired    GoodsRespository goodsRespository;    //查询所有    @Override    public List
   
     findAllGoods() {
           return goodsRespository.findAll();    }    //新增或更新    @Override    public int insertGoods(Goods goods) {
           Goods goods1 = goodsRespository.saveAndFlush(goods);//新增或更新，id为空新增，id不为空更新        if(goods1!=null){
               return 1;        }        return 0;    }    //根据ID查询(注意)    @Override    public Goods findById(int id) {
           Optional
    
      byId = goodsRespository.findById(id);        if(byId.isPresent()){
               Goods goods=byId.get();            return goods;        }        return null;    }    //根据name查询    @Override    public List
     
       findByName(String name) {
           return goodsRespository.findByName(name);    }    //根据ID删除    @Override    public int delete(Map map) {
           Integer id = (Integer) map.get("id");        try {
               goodsRespository.deleteById(id);            return 1;        }catch (Exception e){
               e.printStackTrace();            return 0;        }    }    //根据name和info查询    @Override    public List
      
        findByNameAndInfo(Map map) {
           String name= (String) map.get("name");        String info= (String) map.get("info");        List
       
         byNameAndInfo = goodsRespository.findByNameAndInfo(name, info);        return byNameAndInfo;    }}
       
      
     
    
   

7.controller

@RestControllerpublic class GoodsController {
       @Autowired    GoodsService goodsService;    //查询所有    @RequestMapping("/findAllGoods")    public List
   
     findAllGoods(){
           return goodsService.findAllGoods();    }    //新增或更新    @RequestMapping("/insertGoods")    public int insertGoods(@RequestBody Goods goods){
           return goodsService.insertGoods(goods);    }    //根据ID查询    @RequestMapping("/findById/{id}")    public Goods findById(@PathVariable("id") int id){
           return goodsService.findById(id);    }    //根据name查询    @RequestMapping("/findByName")    public List
    
      findByName(@RequestBody Map map){
           String name = (String)map.get("name");        return goodsService.findByName(name);    }    //根据name和info查询    @RequestMapping("/findByNameAndInfo")    public List
     
       findByNameAndInfo(@RequestBody Map map){
           return goodsService.findByNameAndInfo(map);    }    //根据ID删除    @RequestMapping("/delete")    public int delete(@RequestBody Map map){
           return goodsService.delete(map);    }}
     
    
   

8.application.properties

#端口号server.port=8088#数据库连接spring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.datasource.url=jdbc:mysql://127.0.0.1:3306/qf?useUnicode=true&characterEncoding=utf8&useSSL=falsespring.datasource.username=rootspring.datasource.password=123456#mybatis 给别名mybatis.type-aliases-package=com.wo.pojomybatis.mapper-locations=classpath:mapper/*Mapper.xml#视图解析spring.mvc.view.prefix=/WEB-INF/spring.mvc.view.suffix=.jsp#JPA的配置spring.jpa.database=mysql#是否来展示执行的SQLspring.jpa.show-sql=true#是否自动生来生成表或者字段spring.jpa.generate-ddl=true

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