HTTP 请求头中的 Remote_Addr，X-Forwarded-For，X-Real-IP | Spring Cloud 13

在Spring Cloud中，可以通过HttpServletRequest对象获取到Remote_Addr, X-Forwarded-For, X-Real-IP等HTTP请求头信息。

解决方案1：直接在Controller中注入HttpServletRequest对象

import javax.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
@RestController
public class TestController {
 
    @RequestMapping("/test")
    public String test(HttpServletRequest request) {
        String remoteAddr = request.getRemoteAddr();
        String xForwardedFor = request.getHeader("X-Forwarded-For");
        String xRealIp = request.getHeader("X-Real-IP");
        return "RemoteAddr: " + remoteAddr + ", X-Forwarded-For: " + xForwardedFor + ", X-Real-IP: " + xRealIp;
    }
}

解决方案2：使用@Autowired注入RequestContextHolder

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
@RestController
public class TestController {
 
    @RequestMapping("/test")
    public String test() {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();
        String remoteAddr = request.getRemoteAddr();
        String xForwardedFor = request.getHeader("X-Forwarded-For");
        String xRealIp = request.getHeader("X-Real-IP");
        return "RemoteAddr: " + remoteAddr + ", X-Forwarded-For: " + xForwardedFor + ", X-Real-IP: " + xRealIp;
    }
}

解决方案3：使用过滤器获取

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
 
public class MyFilter implements Filter {
 
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {