整合JDBC+druid+MyBatis


1)jdbc


Sping Data 官网:https://spring.io/projects/spring-data

数据库相关的启动器 :可以参考官方文档:

https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#using-boot-starter


application.yml:

spring:
  datasource:
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatistest?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT

配置完这些东西后,我们就可以直接去使用了,因为SpringBoot已经默认帮我们进行了自动配置

测试:

@RestController
public class HelloController {

    @Autowired
    JdbcTemplate jdbcTemplate;

    @RequestMapping("/select")
    public  List<Map<String, Object>> select(){

        String sql="select * from user";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }

}

JDBCTemplate

  • 即使不使用第三方第数据库操作框架,如 MyBatis等,Spring 本身也对原生的JDBC 做了轻量级的封装,即JdbcTemplate

  • 数据库操作的所有 CRUD 方法都在 JdbcTemplate 中。

  • Spring Boot 不仅提供了默认的数据源,同时默认已经配置好了 JdbcTemplate 放在了容器中,程序员只需自己注入即可使用

  • JdbcTemplate 的自动配置是依赖 org.springframework.boot.autoconfigure.jdbc 包下的 JdbcTemplateConfiguration 类

JDBCTemplate主要提供以下几类方法:

  • execute方法:可以用于执行任何SQL语句,一般用于执行DDL语句;

  • update方法及batchUpdate方法:update方法用于执行新增、修改、删除等语句;batchUpdate方法用于执行批处理相关语句;

  • query方法及queryForXXX方法:用于执行查询相关语句;

  • call方法:用于执行存储过程、函数相关语句。



2)druid



        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.21</version>
        </dependency>


DruidConfig:

@Configuration
public class DruidConfig {

    //将自定义的 Druid数据源添加到容器中,不再让 Spring Boot 自动创建
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druidDataSource(){
        return new DruidDataSource();
    }

    //后台监控,相当于web.xml
    //因为springboot内置了servlet,没有web.xml,因此用ServletRegistrationBean来替代
    @Bean
    public ServletRegistrationBean statViewServlet(){

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

        //后台登录的账号密码
        HashMap<String, String> initParameters = new HashMap<>();
        //增加配置
        initParameters.put("LoginUsername","admin");//这里的key是固定的
        initParameters.put("LoginPassword","123456");
        //允许谁可以访问
        //initParameters.put("allow","");//默认允许所有都可以访问
        
        srb.setInitParameters(initParameters);//设置初始化参数
        return srb;
    }


    //过滤器
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean frb = new FilterRegistrationBean();

        frb.setFilter(new WebStatFilter());
        //可以过滤的请求
        HashMap<Object, Object> initParameters = new HashMap<>();
        initParameters.put("exclusions","*.js,*.css,/druid/*");

        frb.setInitParameters(initParameters);
        return frb;

    }

}


applcation.yml:

spring:
  datasource:
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatistest?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT
    type: com.alibaba.druid.pool.DruidDataSource

    #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
    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,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
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500



参考链接:https://mp.weixin.qq.com/s/wVAGOP1JdXZi5DMEsX1Aug



3)mybatis


1.mybatis整合包:


<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

2.配置数据库连接信息(同上不变)


3.编写代码

注意:这里为了测试,可以先不写service层,实际业务中需要写service层


UserMapper.xml:

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.kakafa.springbootjdbc.mapper.UserMapper">

    <select id="getUserList" resultType="user">
        select * from mybatistest.user;
    </select>
    <select id="getUserById" parameterType="int" resultType="user">
        select * from mybatistest.user where id = #{id};
    </select>
    <insert id="addUser" parameterType="user" >
        insert into mybatistest.user(id,name,pwd) values(#{id},#{name},#{pwd});
    </insert>
    <update id="updateUser" parameterType="user">
        update mybatistest.user
        set name=#{name},pwd=#{pwd}
        where id=#{id};
    </update>
    <delete id="deleteUser" parameterType="int">
        delete
        from mybatistest.user
        where id=#{id};
    </delete>

</mapper>

UserMapper:

@Mapper //是mybatis中的注解,表示将UserMapper交给Spring
@Repository //是springboot中的注解,表示这是一个dao层的类
//这个@Repository加不加都可以,因为@Mapper已经交给Spring容器管理了
public interface UserMapper {

    //获取全部用户
    List<User> getUserList();

    //根据id查询用户
    User getUserById(int id);

    //插入一个用户
    int addUser(User user);

    //修改用户
    int updateUser(User user);

    //删除用户
    int deleteUser(int id);

}

UserController:

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/queryUserList")
    public  List<User> queryUserList(){
        List<User> userList = userMapper.getUserList();
        return userList;
    }

}

yml中要配置mybatis:


4.pom.xml中解决静态资源导出问题


    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>


4)一些JDBC和数据源的解释



参考链接:https://www.cnblogs.com/goloving/p/14884802.html



posted @ 2022-03-03 16:16  卡卡发  阅读(158)  评论(0)    收藏  举报