获取request header的值

1Sring mvc 中可以通过注解  ：

@RequestHeader ("host") String hostName

2httpservletrequest request

request.getHeader("Host") 

//遍历全部

 Enumeration headerNames = request.getHeaderNames();
    while (headerNames.hasMoreElements()) {
        String key = (String) headerNames.nextElement();
        String value = request.getHeader(key);
        
    }