Java编程IP地址和数字相互转换代码示例

public long ipToLong(String ipAddress) { 
 
long result = 0; 
 
String[] ipAddressInArray = ipAddress.split("\\."); 
 
for (int i = 3; i >= 0; i--) { 
 
  long ip = Long.parseLong(ipAddressInArray[3 - i]); 
 
  //left shifting 24,16,8,0 and bitwise OR 
 
  //1. 192 << 24 
  //1. 168 << 16 
  //1. 1  << 8 
  //1. 2  << 0 
  result |= ip << (i * 8); 
 
} 
return result; 
 } 

//ip = 3232235778 
 public String longToIp(long ip) { 
StringBuilder result = new StringBuilder(15); 
 
for (int i = 0; i < 4; i++) { 
 
  result.insert(0,Long.toString(ip & 0xff)); 
 
  if (i < 3) { 
    result.insert(0,'.'); 
  } 
 
  ip = ip >> 8; 
} 
return result.toString(); 
 } 
 
 //ip = 3232235778 
 public String longToIp2(long ip) { 
 
return ((ip >> 24) & 0xFF) + "."  
  + ((ip >> 16) & 0xFF) + "."  
  + ((ip >> 8) & 0xFF) + "."  
  + (ip & 0xFF); 
 } 

public class JavaBitwiseExample { 
  
  public static void main(String[] args) { 
  
    JavaBitwiseExample obj = new JavaBitwiseExample(); 
  
    System.out.println("iptoLong : " + obj.ipToLong("192.168.1.2")); 
    System.out.println("iptoLong2 : " + obj.ipToLong2("192.168.1.2")); 
  
    System.out.println("longToIp : " + obj.longToIp(3232235778L)); 
    System.out.println("longToIp2 : " + obj.longToIp2(3232235778L)); 
  
  } 
  
  // example : 192.168.1.2 
  public long ipToLong(String ipAddress) { 
  
    // ipAddressInArray[0] = 192 
    String[] ipAddressInArray = ipAddress.split("\\."); 
  
    long result = 0; 
    for (int i = 0; i < ipAddressInArray.length; i++) { 
  
      int power = 3 - i; 
      int ip = Integer.parseInt(ipAddressInArray[i]); 
  
      // 1. 192 * 256^3 
      // 2. 168 * 256^2 
      // 3. 1 * 256^1 
      // 4. 2 * 256^0 
      result += ip * Math.pow(256, power); 
  
    } 
  
    return result; 
  
  } 
  
  public long ipToLong2(String ipAddress) { 
  
    long result = 0; 
  
    String[] ipAddressInArray = ipAddress.split("\\."); 
  
    for (int i = 3; i >= 0; i--) { 
  
      long ip = Long.parseLong(ipAddressInArray[3 - i]); 
  
      // left shifting 24,16,8,0 and bitwise OR 
  
      // 1. 192 << 24 
      // 1. 168 << 16 
      // 1. 1 << 8 
      // 1. 2 << 0 
      result |= ip << (i * 8); 
  
    } 
  
    return result; 
  } 
  
  public String longToIp(long i) { 
  
    return ((i >> 24) & 0xFF) +  
          "." + ((i >> 16) & 0xFF) +  
          "." + ((i >> 8) & 0xFF) +  
          "." + (i & 0xFF); 
  
  } 
  
  public String longToIp2(long ip) { 
    StringBuilder sb = new StringBuilder(15); 
  
    for (int i = 0; i < 4; i++) { 
  
      // 1. 2 
      // 2. 1 
      // 3. 168 
      // 4. 192 
      sb.insert(0, Long.toString(ip & 0xff)); 
  
      if (i < 3) { 
        sb.insert(0, '.'); 
      } 
  
      // 1. 192.168.1.2 
      // 2. 192.168.1 
      // 3. 192.168 
      // 4. 192 
      ip = ip >> 8; 
  
    } 
  
    return sb.toString(); 
  } 
}