springboot学习之整合mybatis

1.maven和yml配置文件

<!--        连接数据库-->
        <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
    </dependency>
        <!--连接mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!--连接池包-->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>
        <!--导入druid-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.18</version>
        </dependency>

 2.创建mapper文件

2.1可以在主类上添加扫描mapper包注解

@MapperScan(basePackages="com.cczu.ddd.mapper")

2.2两种写sql语句的方式

　　2.2.1直接在mapper文件上通过注解写sql语句

　　2.2.2在mybatis.xml里面写sql语句

2.3编写mybatis配置类设置驼峰匹配规则。

3.更换Druid数据库驱动

 3.1 编写配置类替代默认的org.apache.tomcat.jdbc.pool.DataSource数据源；

　//　 数据源的相关配置都在DataSourceProperties里面

/**
 * @author ddd
 * @create 2020-01-11    16:12
 **/
@Configuration   //当前类为druid数据库驱动配置类
public class DruidConfig {
    // 对应的是yml里面的datasource配置属性
    @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
    // 一个网站后台，类似tomcat的manager
    @Bean
    public ServletRegistrationBean statViewServlet() {
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String, String> initParams = new HashMap<>();

        initParams.put("loginUsername", "ddd");
        initParams.put("loginPassword", "123456");
        initParams.put("allow", "");//默认就是允许所有访问
        initParams.put("deny", "127.0.0.1");

        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/*"); // 防止拦截，放行

        bean.setInitParameters(initParams);

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

        return bean;

    }
}