What is the method for adding an interceptor in Spring …

The main steps to adding an interceptor in Spring Boot are as follows:

1. Interceptor for handling requests.
2. before handling
3. deal with later
4. Upon finishing
5. Implement custom intercept logic in the interceptor class.
6. Configuration interface for Spring MVC applications
7. includeInterceptors
8. Include interceptors
9. Registry of Interceptors
10. includeInterceptor
11. Include routes
12. Allow web MVC functionality to be enabled.

Here is an example:

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new CustomInterceptor())
                .addPathPatterns("/api/**"); // 拦截以/api开头的请求路径
    }
}

import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CustomInterceptor implements HandlerInterceptor {
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 在请求处理之前进行拦截操作，返回false表示拦截请求，返回true表示放行请求
        return true;
    }
    
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        // 在请求处理之后进行拦截操作，可用于修改响应结果等
    }
    
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // 在请求完成之后进行拦截操作，可用于记录日志等
    }
}

The above is the basic steps for adding an interceptor in Spring Boot, the intercept logic can be implemented based on specific requirements.