@Configuration(proxyBeanMethods = false)
    @Conditional(PooledDataSourceCondition.class)
    @ConditionalOnMissingBean({ DataSource.class, XADataSource.class })
    @Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,
            DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.OracleUcp.class,
            DataSourceConfiguration.Generic.class, DataSourceJmxConfiguration.class })
    protected static class PooledDataSourceConfiguration

@Slf4j
@SpringBootTest
class Boot05WebAdminApplicationTests {

    @Autowired
    JdbcTemplate jdbcTemplate;


    @Test
    void contextLoads() {
        Long aLong = jdbcTemplate.queryForObject("select count(*) from account_tbl", Long.class);
        log.info("记录总数：{}",aLong);
    }

}

@Configuration
public class MyDataSourceConfig {

    /* 默认的自动配置是判断容器中没有才会配 @ConditionalOnMissingBean(DataSource.class)
    * 所以我们自己注入一个便会替换掉系统原有的
    */
    @ConfigurationProperties("spring.datasource")
    @Bean
    public DataSource dataSource() throws SQLException {
        DruidDataSource druidDataSource = new DruidDataSource();
//可以一个个设置，也可以使用@ConfigurationProperties注解绑定配置文件
//        druidDataSource.setUrl();
//        druidDataSource.setUsername();
//        druidDataSource.setPassword();
        //加入监控功能
//        druidDataSource.setFilters("stat,wall");
//        druidDataSource.setMaxActive(10);
        return druidDataSource;
    }
}

//配置 druid的监控页功能
@Bean
public ServletRegistrationBean statViewServlet(){
    StatViewServlet statViewServlet = new StatViewServlet();
    ServletRegistrationBean<StatViewServlet> registrationBean = new ServletRegistrationBean<>(statViewServlet, "/druid/*");

    registrationBean.addInitParameter("loginUsername","admin");
    registrationBean.addInitParameter("loginPassword","admin");

    return registrationBean;
}

访问http://localhost:8080/druid	就会进入后台监控页

ConfigurationProperties("spring.datasource")
@Bean
public DataSource dataSource() throws SQLException {
    DruidDataSource druidDataSource = new DruidDataSource();
//需要给数据源中配置如下属性；可以允许多个filter，多个用，分割
    druidDataSource.setFilters("stat,wall");
    return druidDataSource;
}



//还可以监控web方面的内容
// WebStatFilter 用于采集web-jdbc关联监控的数据。
@Bean
public FilterRegistrationBean webStatFilter(){
    WebStatFilter webStatFilter = new WebStatFilter();

    FilterRegistrationBean<WebStatFilter> filterRegistrationBean = new FilterRegistrationBean<>(webStatFilter);
    filterRegistrationBean.setUrlPatterns(Arrays.asList("/*"));
    filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");

    return filterRegistrationBean;
}

private static final String FILTER_STAT_PREFIX = "spring.datasource.druid.filter.stat";
private static final String FILTER_CONFIG_PREFIX = "spring.datasource.druid.filter.config";
private static final String FILTER_ENCODING_PREFIX = "spring.datasource.druid.filter.encoding";
private static final String FILTER_SLF4J_PREFIX = "spring.datasource.druid.filter.slf4j";
private static final String FILTER_LOG4J_PREFIX = "spring.datasource.druid.filter.log4j";
private static final String FILTER_LOG4J2_PREFIX = "spring.datasource.druid.filter.log4j2";
private static final String FILTER_COMMONS_LOG_PREFIX = "spring.datasource.druid.filter.commons-log";
private static final String FILTER_WALL_PREFIX = "spring.datasource.druid.filter.wall";

@EnableConfigurationProperties(MybatisProperties.class) 
@AutoConfigureAfter({ DataSourceAutoConfiguration.class, MybatisLanguageDriverAutoConfiguration.class })
public class MybatisAutoConfiguration{}


//MyBatis配置项绑定类。
@ConfigurationProperties(prefix = "mybatis")
public class MybatisProperties

@Mapper
public interface CityMapper {

    @Select("select * from city where id=#{id}")
    public City getById(Long id);

    public void insert(City city);

}

@Mapper
public interface CityMapper {

    //注解方式
    @Select("select * from city where id=#{id}")
    public City getById(Long id);

    //通过xml方式
    public void insert(City city);

}

//@MapperScan指定扫描的mapper包。可以指定在任一个配置类上
@MapperScan("com.mg.mapper")
@ServletComponentScan(basePackages = "com.atguigu.admin")
@SpringBootApplication(exclude = RedisAutoConfiguration.class)
public class Boot05WebAdminApplication {

    public static void main(String[] args) {
        SpringApplication.run(Boot05WebAdminApplication.class, args);
    }
}



//配置类上标注了@MapperScan注解指定扫描的mapper包后，就不需要每个接口上都标注@Mapper了
//@Mapper
public interface AccountMapper {
    public Account getAcct(Long id);
}

public interface UserMapper extends BaseMapper<User>{
    
}

    @GetMapping("/user/delete/{id}")
    public String deleteUser(@PathVariable("id") Long id,
                             @RequestParam(value = "pn",defaultValue = "1")Integer pn,
                             RedirectAttributes ra){

        userService.removeById(id);

        ra.addAttribute("pn",pn);
        return "redirect:/dynamic_table";
    }


    @GetMapping("/dynamic_table")
    public String dynamic_table(@RequestParam(value="pn",defaultValue = "1") Integer pn,Model model){
        //表格内容的遍历
//        response.sendError
//     List<User> users = Arrays.asList(new User("zhangsan", "123456"),
//                new User("lisi", "123444"),
//                new User("haha", "aaaaa"),
//                new User("hehe ", "aaddd"));
//        model.addAttribute("users",users);
//
//        if(users.size()>3){
//            throw new UserTooManyException();
//        }
        //从数据库中查出user表中的用户进行展示

        //构造分页参数
        Page<User> page = new Page<>(pn, 2);
        //调用page进行分页
        Page<User> userPage = userService.page(page, null);


//        userPage.getRecords()
//        userPage.getCurrent()
//        userPage.getPages()


        model.addAttribute("users",userPage);

        return "table/dynamic_table";
    }

//Mybatis-plus也可以对service层进行简化
//IService,ServiceImpl都是mybatis-plus提供的用于简化service的
//这样的好处就是自己基本不需要写方法的实现了，很多的增删改查方法直接使用mybatis-plus提供的就好了
public interface UserService extends IService<User> {

}

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper,User> implements UserService {

}

@AllArgsConstructor
@NoArgsConstructor
@Data
//如果不指定，默认是会去找和类名相同的表明，比如此示例中就会去找user表
@TableName("user_tbl")
public class User {

    /**
     * 所有属性都应该在数据库中，如果不存在则可以使用@TableField(exist = false)  
     */
    //当前属性表中不存在
    @TableField(exist = false)  
    private String userName;
    @TableField(exist = false)
    private String password;


    //以下是数据库字段
    private Long id;
    private String name;
    private Integer age;
    private String email;


}

    @Test
    void testRedis(){
        ValueOperations<String, String> operations = redisTemplate.opsForValue();

        operations.set("hello","world");

        String hello = operations.get("hello");
        System.out.println(hello);
    }