如何根據HttpServletRequest判斷請求方是內網還是外網

這里直接上代碼：

package com.fusion;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import sun.net.util.IPAddressUtil;

import javax.servlet.http.HttpServletRequest;

@SpringBootApplication
@RestController
public class StartApplication {
    public static void main(String[] args) {
        SpringApplication.run(StartApplication.class, args);
    }

    @GetMapping("/hello")
    public String hello(HttpServletRequest request) {
        String ip=getIpAddress(request);
        boolean isinter=internalIp(ip);
        return String.format("Hello,the request ip is %s,the netType is %s", ip,isinter?"內網":"外網");
    }

    public static String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

    public boolean internalIp(String ip) {
        if("127.0.0.1".equals(ip)){
            return true;
        }
        byte[] addr = IPAddressUtil.textToNumericFormatV4(ip);
        return internalIp(addr);
    }

    public boolean internalIp(byte[] addr) {
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        //10.x.x.x/8
        final byte SECTION_1 = 0x0A;
        //172.16.x.x/12
        final byte SECTION_2 = (byte) 0xAC;
        final byte SECTION_3 = (byte) 0x10;
        final byte SECTION_4 = (byte) 0x1F;
        //192.168.x.x/16
        final byte SECTION_5 = (byte) 0xC0;
        final byte SECTION_6 = (byte) 0xA8;
        switch (b0) {
            case SECTION_1:
                return true;
            case SECTION_2:
                if (b1 >= SECTION_3 && b1 <= SECTION_4) {
                    return true;
                }
            case SECTION_5:
                switch (b1) {
                    case SECTION_6:
                        return true;
                }
            default:
                return false;
        }
    }
}