五.SpringBoot与数据访问

1.整合jdbc

<dependency>
    <groupId>org.springframework.boot</groupId>            
        <artifactId>spring‐boot‐starter‐jdbc</artifactId>            
    </dependency>        
    <dependency>        
    <groupId>mysql</groupId>            
        <artifactId>mysql‐connector‐java</artifactId>            
    <scope>runtime</scope>            
</dependency> 

jdbc.yml

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://192.168.15.22:3306/jdbc
    driver‐class‐name: com.mysql.jdbc.Driver

2.整合Druid数据源

导入jar包

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.21</version>
        </dependency>

1 代码

@Configuration
public class DruidConfig {

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

    //配置Druid的监控
    //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,*.css,/druid/*");

        bean.setInitParameters(initParams);

        bean.setUrlPatterns(Arrays.asList("/*"));

        return  bean;
    }
}

2. yml文件

spring:
    #Spring Boot 默认是不注入这些属性值的，需要自己绑定
    #druid 数据源专有配置
    druid:
      initial-size: 5
      max-active: 20
      max-wait: 60000
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 300000
      validation-query: SELECT 1 from DUAL
      test-on-return: false
      test-on-borrow: false
      test-while-idle: true
      pool-prepared-statements: true
 
      #配置监控统计拦截的filters，stat:监控统计、log4j：日志记录、wall：防御sql注入
      #如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
      #则导入 log4j 依赖即可，Maven 地址： https://mvnrepository.com/artifact/log4j/log4j
      filters: stat,wall,log4j
      max-pool-prepared-statement-per-connection-size: 20
      use-global-data-source-stat: true
      connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
 

3. 整合MyBatis

3.1 导入jar包

<dependency>        
    <groupId>org.mybatis.spring.boot</groupId>            
    <artifactId>mybatis‐spring‐boot‐starter</artifactId>            
    <version>1.3.1</version>            
</dependency>

3.2 配置规则

1. 代码版

@org.springframework.context.annotation.Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer(){
            @Override
            public void customize(Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

2. yml

mybatis:
  config‐location: classpath:mybatis/mybatis‐config.xml 指定全局配置文件的位置
  mapper‐locations: classpath:mybatis/mapper/*.xml  指定sql映射文件的位置

4. 使用MapperScan批量扫描所有的Mapper接口

@MapperScan(value = "com.atguigu.springboot.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {
    public static void main(String[] args) {    
        SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);        
    }    
}