package com.ten; 
import com.alibaba.druid.pool.DruidDataSource;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component; 
import javax.sql.DataSource;
 
@SpringBootApplication
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
@MapperScan("com.ten.mapper")
class LcWebApplication {
    public static void main(String[] args) {
        SpringApplication.run(LcWebApplication.class, args);
    }
 
    @Autowired
    private Environment env;
 
    //destroy-method="close"的作用是當(dāng)數(shù)據(jù)庫連接不使用的時(shí)候,就把該連接重新放到數(shù)據(jù)池中,方便下次使用調(diào)用.
    @Bean
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl(env.getProperty("spring.datasource.url"));
        dataSource.setUsername(env.getProperty("spring.datasource.username"));//用戶名
        dataSource.setPassword(env.getProperty("spring.datasource.password"));//密碼
        dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
        dataSource.setInitialSize(2);//初始化時(shí)建立物理連接的個(gè)數(shù)
        dataSource.setMaxActive(20);//最大連接池?cái)?shù)量
        dataSource.setMinIdle(0);//最小連接池?cái)?shù)量
        dataSource.setMaxWait(60000);//獲取連接時(shí)最大等待時(shí)間，單位毫秒。
        dataSource.setValidationQuery("SELECT 1");//用來檢測(cè)連接是否有效的sql
        dataSource.setTestOnBorrow(false);//申請(qǐng)連接時(shí)執(zhí)行validationQuery檢測(cè)連接是否有效
        dataSource.setTestWhileIdle(true);//建議配置為true，不影響性能，并且保證安全性。
        dataSource.setPoolPreparedStatements(false);//是否緩存preparedStatement，也就是PSCache
        return dataSource;
    } 
}

啟動(dòng)類配置文件：

spring:
    datasource:
        name: test
        url: jdbc:mysql://localhost:3306/db
        username: root
        password: root
        # 使用druid數(shù)據(jù)源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        filters: stat
        maxActive: 20
        initialSize: 1
        maxWait: 60000
        minIdle: 1
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: select 'x'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
        maxOpenPreparedStatements: 20 
 
mybatis:
  mapperLocations: classpath*:mapper/*.xml
  typeAliasesPackage: com.ten.entity

啟動(dòng)類依賴

 <!--web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--rest-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>
        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>

DAO類

@Repository
public interface UserMapper {
    String getTest(String test);
}

DAO類依賴

<!-- mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>

目錄結(jié)構(gòu)：