springboot对jpa的支持

springboot对jpa的支持

新建的项目

pom依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.hsl</groupId>
    <artifactId>springboot03</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot03</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <mysql.version>5.1.44</mysql.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
            <version>${mysql.version}</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--jpa-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!--druid-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

yml配置

server:
  port: 80
  servlet:
    context-path: /



spring:
  datasource:
    #1.JDBC
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password: 1234
    druid:
      initial-size: 5
      min-idle: 5
      max-active: 20
      max-wait: 60000
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 30000
      validation-query: SELECT 1 FROM DUAL
      test-while-idle: true
      test-on-borrow: true
      test-on-return: false
      pool-prepared-statements: true
      max-pool-prepared-statement-per-connection-size: 20
      filter:
        stat:
          merge-sql: true
          slow-sql-millis: 5000
      web-stat-filter:
        enabled: true
        url-pattern: /*
        exclusions: "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"
        session-stat-enable: true
        session-stat-max-count: 100
      stat-view-servlet:
        enabled: true
        url-pattern: /druid/*
        reset-enable: true
        login-username: admin
        login-password: admin
        allow: 127.0.0.1
  jpa:
    hibernate:
#      新加字段时数据库表也添加字段
      ddl-auto: update
    show-sql: true

实体类：Students

package com.hsl.springboot03.entity;

import lombok.Data;

import javax.persistence.*;

/**
 * @author water
 * @site www.water.com
 * @company xxx公司
 * @create 2020-01-02 16:26
 */
@Data
@Entity
@Table(name="t_spring_students_2020")
public class Students {
    @Id
    @GeneratedValue
    private Integer sid;
    @Column(length = 100)
    private String sname;
    @Column(length = 2)
    private String sex;
}

执行启动类

测试：

package com.hsl.springboot03.dao;

import com.hsl.springboot03.entity.Students;
import org.springframework.data.jpa.repository.JpaRepository;

/**
 * @author water
 * @site www.water.com
 * @company xxx公司
 * @create 2020-01-02 16:38
 * 增删改查
 */
public interface StudentsDao extends JpaRepository<Students,Integer> {
}

controller层：StudentsController

package com.hsl.springboot03.controller;

import com.hsl.springboot03.dao.StudentsDao;
import com.hsl.springboot03.entity.Students;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * @author water
 * @site www.water.com
 * @company xxx公司
 * @create 2020-01-02 16:45
 */
@RestController
public class StudentsController {
    @Autowired
    private StudentsDao studentsDao;

    /**
     * 删除
     * @param stu
     * @return
     */
    @RequestMapping("/del")
    public String del(Students stu){
        studentsDao.delete(stu);
        return "success";
    }

    /**
     * 添加
     * @param stu
     * @return
     */
    @RequestMapping("/add")
    public String add(Students stu){
        studentsDao.save(stu);
        return "success";
    }

    /**
     * 修改
     * @param stu
     * @return
     */
    @RequestMapping("/edit")
    public String edit(Students stu){
        studentsDao.save(stu);
        return "success";
    }

    /**
     * 查询单个
     * @param sid
     * @return
     */
    @RequestMapping("/selectOne")
    public Students selectOne(Integer sid){

        return studentsDao.findById(sid).get();
    }

    /**
     * 查询所有
     * @return
     */
    @RequestMapping("/selectAll")
    public List<Students> selectAll(){
        return studentsDao.findAll();
    }

}

查询所有

查询单个

修改

删除

添加