SpringBoot05 数据操作01 -> JPA的基本使用、基本使用02

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前提：

创建一个springboot项目

创建一个名为springboottest的MySQL数据库

1 jar包准备

jpa的jar包

mysql驱动的jar包

druid数据库连接池的jar包

lombok工具jar包

注意01： druid的jar包在都如时一定要指定版本，其它的spring boot项目会自动进行版本管理

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.xiangxu</groupId>

    <artifactId>springboot</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <packaging>jar</packaging>

    <name>springboot</name>

    <description>Demo project for Spring Boot</description>

    <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.5.8.RELEASE</version>

        <relativePath/> <!-- lookup parent from repository -->

    </parent>

    <properties>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <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-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

        <!--数据库相关-->

        <dependency>

            <groupId>mysql</groupId>

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

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-data-jpa</artifactId>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>druid</artifactId>

            <version>1.0.19</version>

        </dependency>

        <!--工具-->

        <dependency>

            <groupId>org.projectlombok</groupId>

            <artifactId>lombok</artifactId>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

            </plugin>

        </plugins>

    </build>

</project>

pom.xml

2 数据库连接池配置和JPA配置

spring:

  datasource:

    type: com.alibaba.druid.pool.DruidDataSource # 指定使用druid连接池

    driver-class-name: com.mysql.jdbc.Driver

    username: root

    password: 182838

    url: jdbc:mysql://127.0.0.1/springboottest?characterEncoding=utf-8&useSSL=false

    #最大活跃数

    maxActive: 20

    #初始化数量

    initialSize: 1

    #最大连接等待超时时间

    maxWait: 60000

    #打开PSCache，并且指定每个连接PSCache的大小

    poolPreparedStatements: true

    maxPoolPreparedStatementPerConnectionSize: 20

    #通过connectionProperties属性来打开mergeSql功能；慢SQL记录

    #connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

    minIdle: 1

    timeBetweenEvictionRunsMillis: 60000

    minEvictableIdleTimeMillis: 300000

    validationQuery: select 1 from dual

    testWhileIdle: true

    testOnBorrow: false

    testOnReturn: false

    #配置监控统计拦截的filters，去掉后监控界面sql将无法统计,'wall'用于防火墙

    filters: stat, wall, log4j

  jpa:

    show-sql: true

    hibernate:

      ddl-auto: update

#      format-sql: true # TODO: 配置失败

连接池和JPA配置

package cn.xiangxu.springboot.baseConfig;

import com.alibaba.druid.support.http.StatViewServlet;

import com.alibaba.druid.support.http.WebStatFilter;

import org.springframework.boot.web.servlet.FilterRegistrationBean;

import org.springframework.boot.web.servlet.ServletRegistrationBean;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

/**

 * 配置DRUID访问的Sevlet和filter

 */

@Configuration

public class DruidConfiguration {

    @Bean

    public ServletRegistrationBean statViewServlet(){

        //创建servlet注册实体

        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");

        //设置ip白名单

        servletRegistrationBean.addInitParameter("allow","127.0.0.1");

        //设置ip黑名单，如果allow与deny共同存在时,deny优先于allow

        servletRegistrationBean.addInitParameter("deny","192.168.0.19");

        //设置控制台管理用户

        servletRegistrationBean.addInitParameter("loginUsername","wys");

        servletRegistrationBean.addInitParameter("loginPassword","123456");

        //是否可以重置数据

        servletRegistrationBean.addInitParameter("resetEnable","false");

        return servletRegistrationBean;

    }

    @Bean

    public FilterRegistrationBean statFilter(){

        //创建过滤器

        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());

        //设置过滤器过滤路径

        filterRegistrationBean.addUrlPatterns("/*");

        //忽略过滤的形式

        filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");

        return filterRegistrationBean;

    }

}

druid的servlet和filter配置

jpa基础配置详解：点击前往

druid配置详解：点击前往

3 创建一个实体类

实体类相关注解说明：点击前往

技巧01：lombok的妙用

注意01：使用lombok的坑 -> 即使导入了相关的jar包，lombok的注解在IDEA中时不会生效的，但是项目进行打包后就会生效 -> 解决办法

package cn.xiangxu.springboot.entity.dataObject;

import lombok.Data;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

@Entity

@Data

public class Girl {

    @Id

    @GeneratedValue

    @Column(name = "girlId")

    private Integer id;

    private Integer age;

    private String name;

    public Girl() {

    }

    public Girl(Integer age, String name) {

        this.age = age;

        this.name = name;

    }

}

实体类

4 创建一个与实体类对应的持久层接口

注意01：该接口需要实现一个特定的父接口JpaRepository，继承了这个接口后就该接口就会自动被容器管理，无需再添加注解

chijge cn.xiangxu.springboot.repository;

import cn.xiangxu.springboot.entity.dataObject.Girl;

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

public interface GirlRepository extends JpaRepository<Girl, Integer> {

}

持久层接口

5 创建一个服务层接口

调用持久层对象的相应方法实现简单的增删改查操作

package cn.xiangxu.springboot.service;

import cn.xiangxu.springboot.entity.dataObject.Girl;

import java.util.List;

public interface GirlService {

    Girl saveGirl(Girl girl);

    Girl findGirlOne(Integer id);

    List<Girl> finGirldAll();

}

服务层接口

package cn.xiangxu.springboot.service.serviceImpl;

import cn.xiangxu.springboot.entity.dataObject.Girl;

import cn.xiangxu.springboot.repository.GirlRepository;

import cn.xiangxu.springboot.service.GirlService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

@Service("girlService")

public class GirlServiceImpl implements GirlService {

    @Autowired

    private GirlRepository girlRepository;

    @Override

    public Girl saveGirl(Girl girl) {

        return girlRepository.save(girl);

    }

    @Override

    public Girl findGirlOne(Integer id) {

        return girlRepository.findOne(id);

    }

    @Override

    public List<Girl> finGirldAll() {

        return girlRepository.findAll();

    }

}

服务层接口实现类

6 创建服务层测试类

package cn.xiangxu.springboot.service.serviceImpl;

import cn.xiangxu.springboot.entity.dataObject.Girl;

import cn.xiangxu.springboot.service.GirlService;

import lombok.extern.slf4j.Slf4j;

import org.junit.Assert;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

import static org.junit.Assert.*;

@RunWith(SpringRunner.class)

@SpringBootTest

@Slf4j // 日志相关

public class GirlServiceImplTest {

    @Autowired

    private GirlService girlService;

    @Test

    public void saveGirl() throws Exception {

        Girl girl = new Girl(25, "三少");

        Girl result = girlService.saveGirl(girl);

        log.info("【插入数据】");

        Assert.assertNotEquals(null, result);

    }

    @Test

    public void findGirlOne() throws Exception {

        Girl result = girlService.findGirlOne(1);

        log.info("【查询单个】");

        Assert.assertEquals(new Integer(1), result.getId());

    }

    @Test

    public void finGirldAll() throws Exception {

        List<Girl> girls = girlService.finGirldAll();

        log.info("查询列表");

        Assert.assertNotEquals(new Integer(0), new Integer(girls.size()));

    }

}

服务层测试类

7 具体使用02

说明：不使用数据库连接池，这里只是给出一些特殊的地方

坑01：springboot版本升级后，实体类中的id字段必须根据数据库类型设定对应的默认主键值产生类型

package cn.xiangxu.jpa_demo01.domain.domain_do;

import lombok.Data;

import javax.persistence.*;

/**

 * @author 王杨帅

 * @create 2018-08-12 15:01

 * @desc

 **/

@Entity

@Table(name = "student")

@Data

public class Student {

    @Id

    @GeneratedValue(strategy = GenerationType.IDENTITY)

    private String id;

    private String name;

    private Integer age;

    private String address;

}

Student.java

spring:

  datasource:

    url: jdbc:mysql://127.0.0.1/testdemo?characterEncoding=utf-8&useSSL=false

    username: root

    password: 182838

  jpa:

    properties:

      hibernate:

        format_sql: true

        show_sql: true

配置类

package cn.xiangxu.jpa_demo01.repository;

import cn.xiangxu.jpa_demo01.domain.domain_do.Student;

import org.junit.Assert;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

import static org.junit.Assert.*;

@RunWith(SpringRunner.class)

@SpringBootTest

public class StudentRepositoryTest {

    @Autowired

    private StudentRepository studentRepository;

    @Test

    public void findAll() {

        List<Student> all = studentRepository.findAll();

        Assert.assertTrue(all.size() > 0);

    }

}

测试类