Java如何判断一个IP是否在给定的网段内

public static boolean isIpAddressInSubnet(String ipAddress, String subnetAddress, String subnetMask) throws UnknownHostException {
    InetAddress inetAddress = InetAddress.getByName(ipAddress);
    InetAddress subnet = InetAddress.getByName(subnetAddress);
    InetAddress mask = InetAddress.getByName(subnetMask);

    byte[] inetAddressBytes = inetAddress.getAddress();
    byte[] subnetBytes = subnet.getAddress();
    byte[] maskBytes = mask.getAddress();

    for (int i = 0; i < inetAddressBytes.length; i++) {
        int addressByte = inetAddressBytes[i] & 0xFF;
        int subnetByte = subnetBytes[i] & 0xFF;
        int maskByte = maskBytes[i] & 0xFF;

        if ((addressByte & maskByte) != (subnetByte & maskByte)) {
            return false;
        }
    }

    return true;
}

boolean result = isIpAddressInSubnet("192.168.1.100", "192.168.1.0", "255.255.255.0");
if (result) {
    System.out.println("IP address is in subnet");
} else {
    System.out.println("IP address is not in subnet");
}

/**
 * 判断是否在该网段中
 *
 * @param subnetRange 子网范围 x.x.x.x/xx 形式
 */
public static boolean isIpAddressInSubnet(String ipAddress, String subnetRange) {
    String[] networkips = ipAddress.split("\\.");
    int ipAddr = (Integer.parseInt(networkips[0]) << 24)
            | (Integer.parseInt(networkips[1]) << 16)
            | (Integer.parseInt(networkips[2]) << 8)
            | Integer.parseInt(networkips[3]);
            
    // 拿到主机数       
    int type = Integer.parseInt(subnetRange.replaceAll(".*/", ""));
    int ipCount = 0xFFFFFFFF << (32 - type);
    
    String maskIp = subnetRange.replaceAll("/.*", "");
    String[] maskIps = maskIp.split("\\.");
    
    int cidrIpAddr = (Integer.parseInt(maskIps[0]) << 24)
            | (Integer.parseInt(maskIps[1]) << 16)
            | (Integer.parseInt(maskIps[2]) << 8)
            | Integer.parseInt(maskIps[3]);
            
    return (ipAddr & ipCount) == (cidrIpAddr & ipCount);
}

boolean result = isIpAddressInSubnet("192.168.1.100", "192.168.1.0/24");
if (result) {
    System.out.println("IP address is in subnet");
} else {
    System.out.println("IP address is not in subnet");
}

public static String subnetMaskFromPrefixLength(int prefixLength) {
    if (prefixLength < 0 || prefixLength > 32) {
        throw new IllegalArgumentException("Invalid prefix length");
    }

    int mask = 0xffffffff << (32 - prefixLength);
    return String.format("%d.%d.%d.%d",
        (mask & 0xff000000) >>> 24,
        (mask & 0x00ff0000) >>> 16,
        (mask & 0x0000ff00) >>> 8,
        (mask & 0x000000ff));
}

String subnetMask = subnetMaskFromPrefixLength(24);
System.out.println(subnetMask); // 输出：255.255.255.0