Question

有谁知道如何在Java中将IP地址的十进制表示法转换为二进制形式？请让我知道......

Answer 1

写为a.b.c.d的IP地址可以转换为32位整数值
使用shift and bit-wise inclusive OR运算符作为

(a << 24) | (b << 16) | (c << 8) | d

为安全起见，a,b,c,d中的每一个都有有效范围0-255 - 您可以在转换中检查该字段。
您可以进一步validate the IP address using this regex example。

Answer 2

您可以使用java.net.InetAddress课程。您应该看到的两个方法是getByName和getAddress。这是一个简单的代码示例

import java.net.InetAddress;
import java.net.UnknownHostException;
/* ... */
String ip = "192.168.1.1";
InetAddress address = null;
try {
  address = InetAddress.getByName(ip);
} catch (UnknownHostException e) {
  //Your String wasn't a valid IP Address or host name
}
byte [] binaryIP = address.getAddress();

Answer 3

收集你的建议和其他一些来源，我发现有用的是将InetAdress转换为bit数组，以及BitSet，它可以帮助计算和二进制表示中的（），或（），xor（）

以下示例显示如何将ip转换为二进制和二进制转换为ip。

享受！

public class IpConverter {
public static void main(String[] args) {
    String source = "192.168.1.1";
    InetAddress ip = null;
    try {
        ip = InetAddress.getByName(source);
    } catch (UnknownHostException e) {
        e.printStackTrace();
        return;
    }
    System.out.println( "source : " + ip);

    // To bit sequence ------------
    byte[] binaryIP = ip.getAddress();
    BitSet[] bitsets = new BitSet[binaryIP.length];
    int k = 0;

    System.out.print("to binary: ");
    for (byte b : binaryIP) {
        bitsets[k] = byteToBitSet(b);
        System.out.print( toString( bitsets[k] ) + ".");
        k++;
    }
    System.out.println();

    // Back to InetAdress ---------
    byte[] binaryIP2 = new byte[4];
    k = 0;
    for (BitSet b : bitsets) {
        binaryIP2[k] = bitSetToByte(b);
        k++;
    }

    InetAddress ip2 = null;
    try {
        ip2 = InetAddress.getByAddress(binaryIP2);
    } catch (UnknownHostException e) {
        e.printStackTrace();
        return;
    }

    System.out.println( "flipped back to : " + ip2);
}

public static BitSet byteToBitSet(byte b) {
    BitSet bits = new BitSet(8);
    for (int i = 0; i < 8; i++) {
        bits.set(i, ((b & (1 << i)) != 0) );
    }
    return bits;
}

public static byte bitSetToByte(BitSet bits) {
    int value = 0;
    for (int i = 0; i < 8; i++) {
        if (bits.get(i) == true) {
            value = value | (1 << i);
        }
    }
    return (byte) value;
}

public static byte bitsToByte(boolean[] bits) {
    int value = 0;
    for (int i = 0; i < 8; i++) {
        if (bits[i] == true) {
            value = value | (1 << i);
        }
    }
    return (byte) value;
}

public static boolean[] byteToBits(byte b) {
    boolean[] bits = new boolean[8];
    for (int i = 0; i < bits.length; i++) {
        bits[i] = ((b & (1 << i)) != 0);
    }
    return bits;
}

public static String toString(BitSet bits){
    String out = "";
    for (int i = 0; i < 8; i++) {
        out += bits.get(i)?"1":"0";         
    }
    return out;
}

}

Answer 4

open-source IPAddress Java library可以为您做到这一点。它可以解析各种IP地址格式，包括IPv4或IPv6，并具有产生各种字符串格式的方法，包括二进制格式。免责声明：我是IPAddress库的项目经理。

此代码可以做到：

static void convert(String str) {
    IPAddressString string = new IPAddressString(str);
    IPAddress addr = string.getAddress();
    System.out.println(addr + " in binary is " + addr.toBinaryString());
}

示例：

convert("1.2.3.4");
convert("a:b:c:d:e:f:a:b");

输出为：

1.2.3.4 in binary is 00000001000000100000001100000100
a:b:c:d:e:f:a:b in binary is 00000000000010100000000000001011000000000000110000000000000011010000000000001110000000000000111100000000000010100000000000001011

如何将IP地址的十进制表示转换为二进制？

4 个答案: