16个SpringBoot扩展接口的总结和实例

@Component
public class MyCommandLineRunner implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("Spring Boot应用程序启动时执行的代码");
        // 在这里可以做一些初始化的工作或其他需要在启动时执行的任务
    }
}

@Component
public class MyApplicationRunner implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("Spring Boot应用程序启动时执行的代码");
        // 在这里可以访问Spring应用程序上下文和应用程序参数，并做一些初始化的工作
    }
}

@Configuration
public class MyServletContextInitializer implements ServletContextInitializer {
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        // 添加Servlet
        servletContext.addServlet("myServlet", new MyServlet()).addMapping("/myservlet");
        // 添加Filter
        servletContext.addFilter("myFilter", new MyFilter()).addMappingForUrlPatterns(null, false, "/myfilter/*");
        // 添加Listener
        servletContext.addListener(new MyListener());
    }
}

@Configuration
public class MyFilterConfiguration {
    @Bean
    public FilterRegistrationBean<MyFilter> myFilterRegistration() {
        FilterRegistrationBean<MyFilter> registration = new FilterRegistrationBean<>();
        registration.setFilter(new MyFilter());
        registration.addUrlPatterns("/myfilter/*");
        registration.setOrder(1);
        return registration;
    }
}

@Configuration
public class MyServletConfiguration {
    @Bean
    public ServletRegistrationBean<MyServlet> myServletRegistration() {
        ServletRegistrationBean<MyServlet> registration = new ServletRegistrationBean<>();
        registration.setServlet(new MyServlet());
        registration.addUrlMappings("/myservlet");
        registration.setLoadOnStartup(1);
        return registration;
    }
}

@Component
public class MyHealthIndicator implements HealthIndicator {
    @Override
    public Health health() {
        // 自定义健康检查逻辑
        if (isHealth()) {
            return Health.up().build();
        } else {
            return Health.down().withDetail("Error", "Something went wrong").build();
        }
    }
    private boolean isHealth() {
        // 检查应用程序的健康状态，并返回相应的健康信息
        return true; // 健康
    }
}

@Component
public class MyMetricsExporter implements MetricsExporter {
    @Override
    public Map<String, Object> export() {
        // 导出应用程序的指标数据
        Map<String, Object> metrics = new HashMap<>();
        metrics.put("metric1", getMetric1());
        metrics.put("metric2", getMetric2());
        // ...
        return metrics;
    }
    private int getMetric1() {
        // 获取指标数据1
        return 100;
    }
    private float getMetric2() {
        // 获取指标数据2
        return 3.14f;
    }
}

@Configuration
public class MyWebMvcConfigurer implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 添加拦截器
        registry.addInterceptor(new MyInterceptor()).addPathPatterns("/api/**");
    }
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        // 配置消息转换器
        converters.add(new MyMessageConverter());
    }
    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        // 配置视图解析器
        registry.jsp("/WEB-INF/views/", ".jsp");
    }
}

@Configuration
@EnableWebSecurity
public class MyWebSecurityConfigurer extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // 配置安全规则
        http.authorizeRequests()
            .antMatchers("/api/admin/**").hasRole("ADMIN")
            .antMatchers("/api/user/**").hasAnyRole("ADMIN", "USER")
            .anyRequest().permitAll()
            .and().formLogin().permitAll();
    }
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws

public class CommandLinePropertySource extends PropertySource<String> {
  public CommandLinePropertySource(String name, Map<String, Object> source) {
    super(name, source);
  }
  @Override
  public Object getProperty(String name) {
    return this.source.get(name); 
  }
}

@Component
public class CustomEnvironmentPostProcessor implements EnvironmentPostProcessor {
  @Override
  public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
    Map<String, Object> map = new HashMap<>();
    map.put("custom.property", "value");
    environment.getPropertySources().addFirst(
      new CommandLinePropertySource("customCommandLineProperties", map));
  }
}

@Component
public class MyBean {
  @Value("${custom.property}")
  private String customProperty;
  //...
}

public class CustomDataSourceInitializer implements DataSourceInitializer {
  @Override
  public void initialize(DataSource ds) {
    // 调用DataSource的初始化方法
    ds.getConnection(); 
  }
}

@Configuration
public class DataSourceConfig {
  @Bean
  public DataSourceInitializer dataSourceInitializer() {
    return new CustomDataSourceInitializer();
  }
}

@Configuration
public class DataSourceConfig {
  @Bean
  public DataSource dataSource() {
    // 初始化和配置DataSource bean
  }
}

@Component
public class CustomJmsListenerConfigurer implements JmsListenerConfigurer {
  @Override
  public void configureJmsListeners(JmsListenerEndpointRegistrar registrar) {
    // 自定义注册JMS监听器
  }
}

@Configuration
public class JmsConfig {
  @Bean
  public JmsListenerContainerFactory<?> factory(ConnectionFactory connectionFactory) {
    DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
    factory.setConnectionFactory(connectionFactory);
    return factory;
  }
  @Bean
  public JmsListenerEndpointRegistrar registrar() {
    return new JmsListenerEndpointRegistrar();
  }
}

public class MyJmsListener {
  @JmsListener(destination = "someQueue")
  public void onMessage(String msg) {
    // handle message
  }
}

public class CustomRequestResolver implements OAuth2AuthorizationRequestResolver {
  @Override
  public OAuth2AuthorizationRequest resolve(HttpServletRequest request) {
    // 解析和处理授权请求
    return authRequest; 
  }
}

@Configuration
@EnableOAuth2Client
public class OAuth2Config {
  @Bean
  public OAuth2AuthorizationRequestResolver authorizationRequestResolver() {
    return new CustomRequestResolver();
  }
}

@RestController
public class TestController {
  @Autowired
  OAuth2AuthorizedClientService clientService;
  @GetMapping("/users")
  public String getUsers() {
    // 使用授权客户端请求用户资源
  }
}

@Configuration
public class CustomWebSocketConfig implements WebSocketMessageBrokerConfigurer {
  @Override
  public void configureMessageBroker(MessageBrokerRegistry registry) {
    // 配置消息代理
  }
  @Override
  public void registerStompEndpoints(StompEndpointRegistry registry) {
    // 注册STOMP端点
  }
}

@Configuration
public class WebSocketConfig {
  @Bean
  public CustomWebSocketConfig webSocketConfig() {
    return new CustomWebSocketConfig();
  }
}

@Controller
public class WebSocketController {
  @MessageMapping("/chat")
  public void handleChat(Message msg) {
    // 处理WebSocket请求
  }
}

@Component
public class CustomContainerCustomizer 
   implements EmbeddedServletContainerCustomizer {
  @Override
  public void customize(ConfigurableEmbeddedServletContainer container) {
    container.setPort(8888);
  }
}

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

server.port=8080

@Configuration
public class CustomCacheConfig implements CacheManagerCustomizer<ConcurrentMapCacheManager> {
  @Override
  public void customize(ConcurrentMapCacheManager cacheManager) {
    cacheManager.setCacheNames(Collections.singleton("customCache"));
  }
}

@Configuration
@EnableCaching
public class CacheConfig {
  @Bean
  public ConcurrentMapCacheManager cacheManager() {
    return new ConcurrentMapCacheManager(); 
  }
}

@Cacheable("customCache")
public User findUser(String username) {
  // ...
}