idea 搭建 springboot+jpa

idea 搭建 springboot+jpa

• 老套路了，先下一步。

组名和模块名：

热部署:

生成web相关jar包:

一直下一步完成后打开窗口：
项目结构

• 配置pom

<?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.shp</groupId>
    <artifactId>test_springboot-jpa</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>test_springboot-jpa</name>
    <description>Demo project for Spring Boot</description>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>

        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.6</version>
        </dependency>

        <!--JavaServer Pages Standard Tag Library，JSP标准标签库-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <!--内置tocat对Jsp支持的依赖，用于编译Jsp-->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </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>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>2.2.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>2.2.1.RELEASE</version>
        </dependency>

        <!--导入springUtil-->
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>
    </dependencies>

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

</project>

• .properties和yml的区别

• 修改配置文件为.yml后编辑文件

• application.yml

app:
  name: springbootproject
  pageSize: 10
  author: wangle

# 设置tomcat服务器的端口和访问名
server:
  port: 80
  servlet:
    context-path: /test
spring:
  datasource:
    #数据库地址
    url: jdbc:mysql://localhost:3306/sysauthority?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8
    password: root
    username: root
    # 按照提示更改jdbc.properties配置 com.mysql.jdbc.Driver  改为  com.mysql.cj.jdbc.Driver
    driver-class-name:  com.mysql.cj.jdbc.Driver
    platform: mysql
    type: com.alibaba.druid.pool.DruidDataSource
    initialSize: 1
    minIdle: 3
    maxActive: 20
    # 配置获取连接等待超时的时间
    maxWait: 60000
    # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    minEvictableIdleTimeMillis: 30000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    # 打开PSCache，并且指定每个连接上PSCache的大小
    poolPreparedStatements: true
    maxPoolPreparedStatementPerConnectionSize: 20
    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,wall,slf4j
    # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
      # 合并多个DruidDataSource的监控数据
      #useGlobalDataSourceStat: true

  jpa:
    show-sql: true
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
    #使用springboot jpa，项目启动的时候有个warn的log 解决方案，在配置文件中加入下面这个：
    open-in-view: false

实体类
User.class

package com.shp.test_springbootjpa.user.model;

import javax.persistence.*;

@Entity
@Table(name = "user")
public class User {

    //主键和自增策略
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    //@GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    //和数据库中字段不同时别名。
    @Column(name = "user_name")
    private String userName;
    @Column
    private Integer age;

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Long getId() {
        return id;
    }

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

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }


    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", age=" + age +
                '}';
    }
}

先测试dao层是否可以用:
dao接口:

package com.shp.test_springbootjpa.user.dao;

import com.shp.test_springbootjpa.user.model.User;
import org.springframework.data.jpa.repository.JpaRepository;

//<类名,主键类型>
public interface UserDao extends JpaRepository<User,Long> {

}

测试类:

package com.shp.test_springbootjpa;

import com.shp.test_springbootjpa.user.dao.UserDao;
import com.shp.test_springbootjpa.user.model.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class TestSpringbootJpaApplicationTests {

    @Autowired
    private UserDao userDao;

    @Test
    void contextLoads() {
    }

    @Test
    void query(){
        List<User> users = userDao.findAll();
        for (User user : users) {
            System.out.println(user);
        }
    }

}

可以测试出来结果

业务层接口:

package com.shp.test_springbootjpa.user.service;


import com.shp.test_springbootjpa.user.model.User;

import java.util.List;

public interface IUserService {

    List<User> queryAll();


 }

业务实现

package com.shp.test_springbootjpa.user.service;


import com.shp.test_springbootjpa.user.model.User;

import java.util.List;

public class UserService {
	@Autowired
    private UserDao userDao;
    
    public List<User> queryAll() {
       return userDao.findAll();
    }
 }

控制层

package com.shp.test_springbootjpa.user.controller;

import com.shp.test_springbootjpa.user.model.User;
import com.shp.test_springbootjpa.user.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired//注入接口。
    private IUserService userService;

    @RequestMapping("queryAll")//拦截请求到方法中。
    @ResponseBody//返回json对象
    public List<User> queryAll(){
        return userService.queryAll();
    }



}

访问地址得到的结果: