SpringBoot Controller保留@RequestBody参数时如何获取请求IP

有两种常用方案可以在不修改现有方法签名的前提下获取请求IP：

方案一：注入HttpServletRequest #

直接在Controller类中注入HttpServletRequest对象，无需修改方法参数即可调用其API获取IP：

@RestController
public class HelloController {

    // 注入HttpServletRequest
    @Autowired
    private HttpServletRequest request;

    @PostMapping("/coolendpointTWO")
    public String withRequestBody(@RequestBody MyPojo myPojo) {

        System.out.println("received object" + myPojo);
        //handle myPojo with my business logic

        // 获取客户端IP
        String ip = request.getRemoteAddr();
        return "good: " + ip;
    }

}

方案二：使用RequestContextHolder静态获取请求对象 #

如果不想注入HttpServletRequest，可以通过Spring提供的RequestContextHolder工具类静态获取当前请求的上下文，进而拿到请求对象：

@RestController
public class HelloController {

    @PostMapping("/coolendpointTWO")
    public String withRequestBody(@RequestBody MyPojo myPojo) {

        System.out.println("received object" + myPojo);
        //handle myPojo with my business logic

        // 从上下文获取请求对象
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();
        String ip = request.getRemoteAddr();
        
        return "good: " + ip;
    }

}

注意：反向代理场景下的IP获取 #

如果你的服务部署在反向代理（如Nginx、Apache）之后，getRemoteAddr()拿到的会是代理服务器的IP，而非真实客户端IP。此时需要从请求头中读取转发的IP信息，可封装一个工具方法处理：

private String getClientIp(HttpServletRequest request) {
    String ip = request.getHeader("X-Forwarded-For");
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
        ip = request.getHeader("X-Real-IP");
    }
    if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
        ip = request.getRemoteAddr();
    }
    // 如果X-Forwarded-For有多个IP，取第一个非unknown的
    if (ip != null && ip.contains(",")) {
        ip = ip.split(",")[0].trim();
    }
    return ip;
}

调用时直接替换request.getRemoteAddr()为getClientIp(request)即可。

内容的提问来源于stack exchange，提问作者PatPanda