浅谈Springboot实现拦截器的两种方式

@Component
public class LoginInterceptor implements HandlerInterceptor{
	
	private static final Pattern SHOULD_NOT_FILTER_URL_PATTERN;
	
	static {
		List<String> urlList = new ArrayList<>();
		// 将不走拦截器的请求存放到Pattern
		urlList.add("(socket/.*)");
		urlList.add("(user/findUserList)");
		StringBuilder sb = new StringBuilder();
		for (String url : urlList) {
			sb.append(url);
			sb.append("|");
		}
		sb.setLength(sb.length() - 1);
		SHOULD_NOT_FILTER_URL_PATTERN = Pattern.compile(sb.toString());
	}
	
	/**
	 * 在请求处理之前进行调用（Controller方法调用之前）
	 */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {
		
		HttpSession session = request.getSession();
		// 获取访问的url
 		String servletPath = request.getServletPath();
		// 排除特定请求
		if (SHOULD_NOT_FILTER_URL_PATTERN.matcher(servletPath).find()) {
			return true;
		}
		if (session.getAttribute("user") != null) {
			// 可能有的项目在校验完session，还会校验token
			String token = request.getHeader("access_token");
			// 此处业务省略。。。
			return true;
		}
		return false;
	}

	/**
	 * 请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）
	 */
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
		// TODO Auto-generated method stub
		
	}

	/**
	 * 在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）
	 */
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
			throws Exception {
		// TODO Auto-generated method stub
		
	}
}

@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
	
	@Autowired
    private LoginInterceptor loginInterceptor;
	

	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		// 多个拦截器组成一个拦截器链
		// addPathPatterns 用于添加拦截规则
		// excludePathPatterns 用户排除拦截
		registry.addInterceptor(loginInterceptor).addPathPatterns("/**");
		super.addInterceptors(registry);
	}
}

@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
	
	// 这么写的目的是为了在SessionInterceptor中能注入spring中的service
	@Bean
	LoginInterceptor loginInterceptor() {
		return new LoginInterceptor();
	}

	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		// 多个拦截器组成一个拦截器链
		// addPathPatterns 用于添加拦截规则
		// excludePathPatterns 用户排除拦截
		registry.addInterceptor(loginInterceptor()).addPathPatterns("/**");
		super.addInterceptors(registry);
	}
}

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.springframework.stereotype.Component;

@Component
@WebFilter(filterName = "requestParamFilter",urlPatterns = "/*")
public class RequestParamFilter implements Filter {

	private static final Pattern SHOULD_NOT_FILTER_URL_PATTERN;
	
	static {
		List<String> urlList = new ArrayList<>();
		// 将不走拦截器的请求存放到Pattern
		urlList.add("(socket/.*)");
		urlList.add("(user/findUserList)");
		StringBuilder sb = new StringBuilder();
		for (String url : urlList) {
			sb.append(url);
			sb.append("|");
		}
		sb.setLength(sb.length() - 1);
		SHOULD_NOT_FILTER_URL_PATTERN = Pattern.compile(sb.toString());
	}

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }
	
	// 发送请求会执行这个方法
    // 一个doFilter相当于拦截器的执行前和执行后
    // filterChain.doFilter后面的内容就是执行后的内容，假如不执行filterChain.doFilter方法相当于方法被拦截
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,
                         FilterChain filterChain) throws IOException, ServletException {
        System.out.println("sunhan---请求参数过滤器！---test1");
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpSession session = request.getSession();
		// 获取访问的url
 		String servletPath = request.getServletPath();
		// 排除特定请求
		if (SHOULD_NOT_FILTER_URL_PATTERN.matcher(servletPath).find()) {
			filterChain.doFilter(servletRequest,servletResponse);
		}
        System.out.println("开始拦截了................");
        //业务代码
    }

    @Override
    public void destroy() {

    }
}