Spring Boot与Spring Data JPA

Posted 2020-10-07 hct118

0、编辑properties

spring.datasource.url = jdbc:mysql://localhost:3306/test
spring.datasource.username = root
spring.datasource.password = 123456
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.max-active=20
spring.datasource.max-idle=8
spring.datasource.min-idle=8
spring.datasource.initial-size=10
# Specify the DBMS
spring.jpa.database = MYSQL
# Show or not log for each sql query
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update
# Naming strategy
#[org.hibernate.cfg.ImprovedNamingStrategy #org.hibernate.cfg.DefaultNamingStrategy]
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

1、创建实体类bean

package com.example.bean;

import javax.persistence.*;

@Table(name="grade")
@Entity
public class Grade {
    @Id @GeneratedValue(strategy = GenerationType.AUTO)//id和GeneratedValue必须同时使用
    private int id;
    private String gradeNM;
    private int teacherID;

    @Override
    public String toString() {
        return "Grade{" +
                "id=" + id +
                ", gradeNM=\'" + gradeNM + \'\\\'\' +
                ", teacherID=" + teacherID +
                \'}\';
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getGradeNM() {
        return gradeNM;
    }

    public void setGradeNM(String gradeNM) {
        this.gradeNM = gradeNM;
    }

    public int getTeacherID() {
        return teacherID;
    }

    public void setTeacherID(int teacherID) {
        this.teacherID = teacherID;
    }
}

 

2、创建repository

　　1）CrudRepository

package com.example.reposittory;

import com.example.bean.Grade;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;

public interface GradeCrudRepository extends CrudRepository<Grade,Integer> {

    public Grade findByGradeNM(String gradeNM);

    @Query(value = "from Grade b where gradeNM=:nm")
    public Grade findMyGrade(@Param("nm") String gradeNM);


    

}

　　2）Repository

package com.example.reposittory;

import com.example.bean.Grade;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.Repository;
import org.springframework.data.repository.query.Param;

public interface GradeRepository extends Repository<Grade,Integer> {
    public Grade findByGradeNM(String gradeNM);

    @Query(value = "from Grade b where gradeNM=:nm")
    public Grade findMyGrade(@Param("nm") String gradeNM);


}

　　3）PagingAndSortingRepository

package com.example.reposittory;

import com.example.bean.Grade;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;

public interface GradePageAndSortRepository extends PagingAndSortingRepository<Grade,Integer> {

     Grade findByGradeNM(String gradeNM);

    @Query(value = "from Grade b where gradeNM=:nm")
     Grade findMyGrade(@Param("nm") String gradeNM);


    

}

 

3、创建service

package com.example.service;

import com.example.bean.Grade;
import com.example.reposittory.GradeRepository;
import com.example.reposittory.GradeCrudRepository;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import javax.transaction.Transactional;

@Service
public class GradeService {
    @Resource
    private GradeRepository gradeRepository;
    @Resource
    private GradeCrudRepository gradeRepository2;
    @Resource
    private PagingAndSortingRepository gradeRepository3;

    public Grade findByGradeNM(String gradeNM){
        Grade byGradeNm = gradeRepository.findByGradeNM(gradeNM);
        return byGradeNm;

    }
    public Grade findMyGrade(String gradeNM){
        Grade byGradeNm = gradeRepository.findMyGrade(gradeNM);
        return byGradeNm;

    }
    @Transactional
    public  void save(Grade grade){
        gradeRepository2.save(grade);
    }
    @Transactional
    public  void delete(int id){
        gradeRepository2.delete(id);
    }
    public Iterable<Grade> getAll(){
        return gradeRepository3.findAll(new PageRequest(0,3));
    }

}

 

4、创建control

package com.example.controller;

import com.example.bean.Grade;
import com.example.service.GradeService;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

@RestController
public class GradeController {
    @Resource
    private GradeService gradeService;

    @RequestMapping("/findbygradeNM")
    public Grade findByGradeNM(String gradeNM) {
        Grade byGradeNM = gradeService.findByGradeNM(gradeNM);
        return byGradeNM;
    }

    @RequestMapping("/findmygradeNM")
    public Grade findMyGrade(String gradeNM) {
        Grade byGradeNM = gradeService.findMyGrade(gradeNM);
        return byGradeNM;
    }

    @RequestMapping("/save")
    public String save(@RequestParam("gradeNM") String gradeNM, @RequestParam("id") int id) {
        Grade grade = new Grade();
        grade.setGradeNM(gradeNM);
        grade.setTeacherID(id);
        gradeService.save(grade);
        return "success";
    }

    @RequestMapping("/delete")
    public String delete(int id) {
        gradeService.delete(id);
        return "success";
    }

    @RequestMapping(value = "/getAll",method = RequestMethod.GET)
    public @ResponseBody  List<Grade> getAll() {
        Iterable<Grade> all = gradeService.getAll();
        Iterator<Grade> iterator = all.iterator();
        List<Grade> grades = new ArrayList<>();
        while (iterator.hasNext()) {
            Grade grade = iterator.next();
            grades.add(grade);
        }
        return grades;
    }

}

 

5、spring boot启动入口

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class HctSpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(HctSpringBootApplication.class, args);
    }
}

6、测试

1)查询所有

2）保存数据