table of Contents

https://gitee.com/cxy-xupeng/spring-boot-test.git

1. Connect to the database and be able to access

2. Integrate basic JDBC and data sources

By default, SpringBoot adopts the unified processing method of integrating Spring Data, adding a large number of automatic configurations, and shielding many settings.

git address:

spring-boot-test.git

1. Connect to the database and be able to access

Let's create a project first

Select spring web under web and JDBC and MySQL drivers under SQL

After creating the project, you will find that we have introduced the following drivers:

And we also use the previous database:

table of Contents:

We don’t use application.properties this time, we use application.yml:

spring:
  datasource:
    username: root
    password: xp880000
    url: jdbc:mysql://localhost:3306/xupeng?serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver

测试类Springboot05DataJdbcApplicationTests

@SpringBootTest
@RunWith(SpringRunner.class)
public class Springboot05DataJdbcApplicationTests {

    @Autowired
    public DataSource dataSource;

    @Test
    public void contextLoads() throws SQLException {
        System.out.println(dataSource.getClass());

        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

}

Note: If you start to report an error as follows

警告: Runner org.junit.internal.runners.ErrorReportingRunner (used on class com.xupeng.Springboot05DataJdbcApplicationTests) does not support filtering and will therefore be run completely.

import org.junit.Test;

Remember to replace the guide package corresponding to your @Test with this

result:

We are writing a class:

HelloController ：

@Controller
public class HelloController {
    @Autowired
    JdbcTemplate jdbcTemplate;

    @ResponseBody
    @RequestMapping("/query")
    public Map<String,Object> map(){
        List<Map<String, Object>> list = jdbcTemplate.queryForList("select * from account");
        return list.get(0);
    }

}

Database table account:

result:

2. Integrate basic JDBC and data sources

First look at the directory structure:

1. Introduce druid data source

pom.xml ：

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.8</version>
        </dependency>

application.yml: add type to set the data source, and set some attributes of druid below

spring:
  datasource:
    username: root
    password: xp880000
    url: jdbc:mysql://localhost:3306/xupeng?serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    #   数据源其他配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    #   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
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

DruidConfig: configure filter

package com.xupeng.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
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;

import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return new DruidDataSource();
    }

    //配置Druid监控
    //1.配置一个管理后台的servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");

        Map<String,String> initParams = new HashMap<>();
        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");

        bean.setInitParameters(initParams);
        return bean;
    }

    //2.配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());

        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");

        bean.setInitParameters(initParams);
        bean.setUrlPatterns(Arrays.asList("/*"));
        return bean;
    }
}

Check the result: Let's first go to the management background servlet set by ourselves, the login name and password are set by ourselves above

Then we check the sql monitoring after making a query:

Three, integrate mybatis

First look at the directory:

User

public class User {
    private Integer id;
    private String username;
    private String password;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

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

UserMapper

public interface UserMapper {
    List<User> getAllUser();
}

UserMapper.xml (The xml file is best placed under resources, don’t mess around)

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xupeng.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.xupeng.domain.User" >
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="username" property="username" jdbcType="VARCHAR" />
        <result column="password" property="password" jdbcType="VARCHAR" />
    </resultMap>

    <select id="getAllUser" resultMap="BaseResultMap">
        select * from user
    </select>
</mapper>

DruidConfig

@Configuration
public class DruidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return new DruidDataSource();
    }

    //配置Druid监控
    //1.配置一个管理后台的servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");

        Map<String,String> initParams = new HashMap<>();
        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");

        bean.setInitParameters(initParams);
        return bean;
    }

    //2.配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());

        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");

        bean.setInitParameters(initParams);
        bean.setUrlPatterns(Arrays.asList("/*"));
        return bean;
    }
}

UserService

public interface UserService {
    List<User> getAllUser();
}

UserServiceImpl

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    UserMapper userMapper;

    @Override
    public List<User> getAllUser() {
        return userMapper.getAllUser();
    }
}

UserController

@Controller
public class UserController {
    @Autowired
    UserService userService;

    @RequestMapping(value = "getusers",method = RequestMethod.GET)
    @ResponseBody
    public List<User> getUsers(){
        List<User> userList = userService.getAllUser();
        return userList;
    }

}

Springboot05MybatisApplication

@SpringBootApplication
@MapperScan(value = "com.xupeng.mapper")
public class Springboot05MybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot05MybatisApplication.class, args);
    }

}

result:

Fourth, integrate JPA

Let's build a project first:

Let's take a look at the directory first:

User：

package com.xupeng.entity;

import javax.persistence.*;

//使用JPA注解配置映射关系
@Entity
@Table(name = "user")//如果省略，默认表名就是user
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)//自增主键
    private Integer id;

    @Column(name = "username",length = 255)
    private String username;

    @Column //省略默认列名就是属性
    private String password;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

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

UserRepository: Note here that the type behind JpaRepository<User,Integer> must be specified, otherwise an error will be reported. And the class can be directly referenced

package com.xupeng.repository;

import com.xupeng.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;

//继承JpaRepository来完成对数据库的操作
public interface UserRepository extends JpaRepository<User,Integer> {

}

UserController

package com.xupeng.controller;

import com.xupeng.entity.User;
import com.xupeng.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {
    @Autowired
    UserRepository userRepository;

    @GetMapping("/user")
    public List<User> getUser(){
        List<User> userList = userRepository.findAll();
        return userList;
    }
}

result:

59. SpringBoot and data access (integration of mybatis, jpa)

https://gitee.com/cxy-xupeng/spring-boot-test.git

1. Connect to the database and be able to access

2. Integrate basic JDBC and data sources

Three, integrate mybatis

Fourth, integrate JPA

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