java - 如何使用 HttpServletRequest 在 Java 中捕获请求头

Question

我想在java中捕获一个标题。我写的代码是正确的。尽管如此，它还是空的。能否请您提出更改建议。我正在拦截器中执行此任务。是否有我在 Controller 类上遗漏的任何注释或我需要在 Controller 类上做的任何配置？

import java.io.IOException;

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

import org.apache.log4j.Logger;
import org.jose4j.jwk.HttpsJwks;
import org.jose4j.jwt.JwtClaims;
import org.jose4j.jwt.consumer.InvalidJwtException;
import org.jose4j.jwt.consumer.JwtConsumer;
import org.jose4j.jwt.consumer.JwtConsumerBuilder;
import org.jose4j.keys.resolvers.HttpsJwksVerificationKeyResolver;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

@Configuration
@Component
public class TokenValidateInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {

        String apiKey;
        System.out.println("Header  "+request.getHeader("xx"));  //Null
        System.out.println("request  "+request);  // request  org.apache.catalina.core.ApplicationHttpRequest@4df9ffc7
        System.out.println("request.tostring  "+request.toString()); // request.tostring  org.apache.catalina.core.ApplicationHttpRequest@e0770ef

I am passing the header using POSTMAN

Answer 1

请求中可能不存在“xx” header 。

代替

System.out.println("Header  "+request.getHeader("xx"));

和

Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
    System.out.println("Header  " + headerNames.nextElement());
}

查看服务器从客户端收到的所有 header 。