Filter, Interceptor, Validator, Aop 执行顺序

顺序如下
 

1 filter
    2.1 interceptor-pre
        3 valid参数校验
            4.1 aop-pre
                5.1 业务方法
            4.2 aop-post(校验失败时_不执行)
    2.2 interceptor-post(校验失败时_不执行)
    2.3 interceptor-afterCompletion(校验失败时_任然执行)

============================================

filter 过滤器 https://www.cnblogs.com/huanzi-qch/p/11239167.html
filter: post拿不到参数? POST的请求是在请求体body中，而POST请求中的body参数是已流形式存在的    https://blog.csdn.net/qq_40866897/article/details/111404480

Interceptor 拦截器 https://blog.csdn.net/worilb/article/details/114194446

Validator 参数校验 https://www.cnblogs.com/mooba/p/11276062.html

aop https://ld246.com/article/1551866577094

===========================================

Filter

@WebFilter(filterName = "testFilter", urlPatterns = {"/test"})
@Component
public class TestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        // 获取post时, 请求中的body参数是流的形式存在 request.getRequestParams()拿不到值
        // 所以需要自行封装
        RequestWrapper requestWrapper = new RequestWrapper(request);

        System.out.println("TestFilter," + request.getRequestURI());
        System.out.println(requestWrapper.getBodyString());
        //执行
        filterChain.doFilter(requestWrapper, servletResponse);
    }

    @Override
    public void destroy() {

    }
}

RequestWrapper 防止读取流后, controller获取不到值

import org.springframework.util.StreamUtils;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;


public class RequestWrapper extends HttpServletRequestWrapper {
    private final byte[] body;

    public RequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        //保存一份InputStream，将其转换为字节数组
        body = StreamUtils.copyToByteArray(request.getInputStream());
    }

    //转换成String
    public String getBodyString(){
        return new String(body, StandardCharsets.UTF_8);
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    //把保存好的InputStream，传下去
    @Override
    public ServletInputStream getInputStream() throws IOException {

        final ByteArrayInputStream bais = new ByteArrayInputStream(body);

        return new ServletInputStream() {

            @Override
            public int read() throws IOException {
                return bais.read();
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
            }
        };
    }
}

Interceptor

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...1");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle...3");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("postafterCompletionHandle...4");
    }
}

注册拦截器

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Component
public class MyInterceptorConfig implements WebMvcConfigurer {

    @Autowired
    MyInterceptor myInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(myInterceptor).addPathPatterns("/test").excludePathPatterns("/admin");

    }
}

aop

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class MyLogAspect {

    @Pointcut("@annotation(com.xxx.annotation.MyLog)")
    public void logCut() {
    }

    @Around("logCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        System.out.println("aop start");
        Object result = point.proceed();
        System.out.println("aop end");
        return result;
    }

}

controller

@RestController
@RequestMapping("")
public class TestController {
    @RequestMapping("/test")
    public String test() {
        System.out.println("业务逻辑....2");
        return "success";
    }
}