Spring Boot每天10问--day01

1.spring boot中哪个注解负责开启组件扫描和自动配置？它由于那几个注解组成

@SpringBootApplication

1. @Configuration
2. @ComponentScan
3. @EnableAutoConfiguration

2.spring boot中自定义配置可以放在哪些地方配置？

1.单独的@Configuration标注的类里；
2.可以加入到引导类中

3.spring boot中什么用来继承版本号

spring-boot-starter-parent继承版本号

4.spring boot中起步依赖的名字有什么规则？

spring-boot-starter-前缀

5.如何排除传递依赖？

使用exclusion标签

org.springframework.boot
spring-boot-starter-web


com.fasterxml.jackson.databind
com.fasterxml.jackson.core

6.如何引入某个版本中的某个依赖

  <dependency>
   	<groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-databind</artifactId>
       <version>2.4.3</version>
       </dependency>

7. application.properties和application.yml文件能放在哪些位置？

1)外置：相对于应用程序运行目录的/config子目录里；
2)外置：在应用程序运行的目录里
3)内置：在config包内
4)内置：在Classpath根目录
优先级别由高到低，同一级别时，application.yml里的属性覆盖application.properties里的属性。

8.如何在controller中注入配置文件里的属性

在一个bean中加载配置属性

@Component
@ConfigurationProperties("amazon")
public class AmazonProperties {
    private String associatedId;

    public String getAssociatedId() {
        return associatedId;
    }

    public void setAssociatedId(String associatedId) {
        this.associatedId = associatedId;
    }
}

在controller中对属性进行初始化

@Controller
@RequestMapping("/readingList")
public class BookListController {
    private BookService bookService;

    private AmazonProperties associatedId;

    @Autowired
    public BookListController(BookService bookService,AmazonProperties associatedId){
        this.bookService=bookService;
        this.associatedId=associatedId;
    }

9.如何实现环境的配置切换

application.yml文件内容如下：

spring:
  profiles:
    active: test

其中application-test.yml中的配置如下如所示：

server:
  port: 9082

spring:
  datasource:
    master:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://xxxxxxxx:3306/xxxxxx?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=true&allowMultiQueries=TRUE
      username: xxxxxx
      password: xxxxxxx

  thymeleaf:
    cache: true
    prefix: classpath:/templates/
    suffix: .html
    check-template-location: true
    encoding: utf-8
    mode: HTML

  resources:
    static-locations: classpath:/static/

amazon:
  associateId: habuma-20

10.如何创建安全配置

在maven中引入配置

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

显示安全配置如下：

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Autowired
    ReaderService readerService;
    @Override
    protected void configure(HttpSecurity http) throws Exception{
        http
                .authorizeRequests()
                .antMatchers("/")
                .access("hasRole('READER')")
        .and()
            .formLogin()
                .loginPage("/login")
                .failureUrl("/login?error=true");
    }
    protected  void configure(AuthenticationManagerBuilder auth) throws Exception{
        auth.userDetailsService(new UserDetailsService() {
            @Override
            public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
                return readerService.findOneByUsername(username);
            }
        });
    }
}

本文地址：https://blog.csdn.net/a1773570500/article/details/109591531