计算机网络-子网划分【Java版】
package com;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Main {
// 输入流
public static Scanner sc = new Scanner(System.in);
// 网络地址
public static String networkAddress;
// 借位数
public static int NUM;
// 网络地址的4位数
public static int[] intNetworkAddress = new int[4];
// 网络类型
public static String TYPE;
// 判断是不是合法的网络地址格式
public static boolean isNet1() {
String regStr = "^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$";
return networkAddress.matches(regStr);
}
// 先分割网络地址，再判断是不是ABC三者之一的网络地址
public static boolean isNet2() {
if (isNet1()) {
// 创建匹配器
Matcher matcher = Pattern.compile("[0-9]+").matcher(networkAddress);
// 循环取值
int i = 0;
while (matcher.find()) {
//strNetworkAddress[i] = matcher.group(0);
intNetworkAddress[i] = Integer.parseInt(matcher.group(0));
i++;
}
if (intNetworkAddress[0] >= 0 && intNetworkAddress[0] <= 223) {
return true;
}
}
return false;
}
// 先求网络类型，再判断借位是否合法
public static boolean isNet3() {
if (isNet2()) {
int xx;
int numType = intNetworkAddress[0];
if (numType <= 127) {
TYPE = "A";
xx = 8;
} else if (numType <= 191) {
TYPE = "B";
xx = 16;
} else {
TYPE = "C";
xx = 24;
}
if (xx + NUM <= 30) {
return true;
}
}
return false;
}
// 二进制 ==> 十进制数
public static int erJinZhiToShiJinZhi(String str) {
StringBuffer sb = new StringBuffer(str).reverse();
int sum = 0;
for (int i = 0; i < str.length(); i++) {
int tmp = sb.charAt(i) - 48;
if (tmp == 1) {
sum += Math.pow(2, i);
}
}
return sum;
}
// 十进制 ==> N位二进制
public static String shiJinZhiToErJinZhi(int num, int len) {
StringBuffer sb = new StringBuffer();
while (num != 0) {
sb.append(num % 2);
num /= 2;
}
for(int i = sb.length(); i < len; i++) {
sb.append(0);
}
sb.reverse();
return new String(sb);
}
// 32位二进制 ==> IP
public static String erJinZhiToIPAddress(String ip) {
StringBuffer sb = new StringBuffer(ip);
String[] str = new String[5];
str[1] = erJinZhiToShiJinZhi(sb.substring(0, 8)) + "";
str[2] = erJinZhiToShiJinZhi(sb.substring(8, 16)) + "";
str[3] = erJinZhiToShiJinZhi(sb.substring(16, 24)) + "";
str[4] = erJinZhiToShiJinZhi(sb.substring(24)) + "";
return str[1] + "." + str[2] + "." + str[3] + "." + str[4];
}
// 用户输入信息
public static void enterNetworkAddress() {
System.out.print("请输入网络地址：");
networkAddress = sc.next();
System.out.print("请输入借位数：");
NUM = sc.nextInt();
}
// 判断网络地址是否合法
public static boolean isNetAddress() {
return isNet3();
}
// 获取网络号位数
public static int getNetworkNumberCount() {
if (TYPE == "A") {
return 8;
} else if (TYPE == "B") {
return 16;
} else {
return 24;
}
}
// 获取子网掩码
public static String getMask() {
String mask;
StringBuffer sb = new StringBuffer();
sb.append(\'=\');
for (int i = 1; i <= NUM; i++) {
sb.append(1);
}
for (int i = 1; i <= 32 - NUM - getNetworkNumberCount(); i++) {
sb.append(0);
}
if (TYPE == "A") {
mask = "255";
} else if (TYPE == "B") {
mask = "255.255";
} else {
mask = "255.255.255";
}
int sta = 1;
for (int i = 1; i <= sb.length(); i++) {
if (i % 8 == 0) {
mask = mask + "." + erJinZhiToShiJinZhi(sb.substring(sta, i+1));
sta = i + 1;
}
}
return mask;
}
// 获得第N个借位网络号
public static String getJieWeiNetNumber(int n) {
return shiJinZhiToErJinZhi(n-1, NUM);
}
// 二进制 + 1
public static String erJinZhiAddOne(String ip) {
char[] chs = ip.toCharArray();
int[] arr = new int[35];
for (int i = 1, j = 31; i <= 32; i++,j--) {
arr[i] = chs[j] - 48;
}
arr[1]++;
int flag = 0;
for (int i = 1; i <= 32; i++) {
if (arr[i] + flag == 2) {
arr[i] = 0;
flag = 1;
} else {
arr[i] = arr[i] + flag;
flag = 0;
}
}
for (int i = 1, j = 32; i <= j; i++,j--) {
int tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
StringBuffer sb = new StringBuffer();
for (int i = 1; i <= 32; i++) {
sb.append(arr[i]);
}
return new String(sb);
}
// 二进制 - 1
public static String erJinZhiDelOne(String ip) {
char[] chs = ip.toCharArray();
int[] arr = new int[35];
for (int i = 1, j = 31; i <= 32; i++,j--) {
arr[i] = chs[j] - 48;
}
arr[1]--;
int flag = 0;
for (int i = 1; i <= 32; i++) {
if (arr[i] + flag == -1) {
arr[i] = 1;
flag = -1;
} else {
arr[i] = arr[i] + flag;
flag = 0;
}
}
for (int i = 1, j = 32; i <= j; i++,j--) {
int tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
StringBuffer sb = new StringBuffer();
for (int i = 1; i <= 32; i++) {
sb.append(arr[i]);
}
return new String(sb);
}
// 获取全 1 的主机号
public static String getZZ1() {
StringBuffer sb = new StringBuffer();
for (int i = 1; i <= 32 - NUM - getNetworkNumberCount(); i++) {
sb.append(1);
}
return new String(sb);
}
// 获取全 0 的主机号
public static String getZZ2() {
StringBuffer sb = new StringBuffer();
for (int i = 1; i <= 32 - NUM - getNetworkNumberCount(); i++) {
sb.append(0);
}
return new String(sb);
}
// 获取原来的网络号
public static String getZZ3() {
StringBuffer sb = new StringBuffer();
int ttt;
if (TYPE == "A") {
ttt = 1;
} else if (TYPE == "B") {
ttt = 2;
} else {
ttt = 3;
}
for (int i = 0; i < ttt; i++) {
sb.append(shiJinZhiToErJinZhi(intNetworkAddress[i], 8));
}
return new String(sb);
}
// 主程序
public static void main(String[] args) {
// 用户输入
enterNetworkAddress();
// 判断网络
if (isNetAddress()) {
// 网络类型
System.out.println("网络类型：" + TYPE);
// 可划分子网数
System.out.println("可划分子网数：" + (int)Math.pow(2, NUM));
// 每个子网的可用地址数
System.out.println("每个子网的可用地址数" + ((int)Math.pow(2, 32 - getNetworkNumberCount() - NUM) - 2));
// 子网掩码
System.out.println("子网掩码：" + getMask());
System.out.println("网络地址\t\t\t\t\t可用地址范围\t\t\t\t\t\t\t\t广播地址");
for (int i = 1; i <= (int)Math.pow(2, NUM); i++) {
/** 子网的网络地址【二进制】 */
String xx = getZZ3() + getJieWeiNetNumber(i) + getZZ2();
/** 子网的广播地址【二进制】 */
String zz = getZZ3() + getJieWeiNetNumber(i) + getZZ1();
/** 网络地址 + 1【点分十进制】 */
String yy1 = erJinZhiToIPAddress(erJinZhiAddOne(xx));
/** 广播地址 - 1【点分十进制】 */
String yy2 = erJinZhiToIPAddress(erJinZhiDelOne(zz));
System.out.println(erJinZhiToIPAddress(xx) + "\t\t\t\t" + yy1 + "---" + yy2 + "\t\t\t\t" + erJinZhiToIPAddress(zz));
}
}
else {
System.out.println("请输入正确的信息！！！");
}
}
}