java实现ip地址与十进制数相互转换

classip
{
privatestaticlongiptolong(stringstrip)
//将127.0.0.1形式的ip地址转换成10进制整数，这里没有进行任何错误处理
{
intj=0;
inti=0;
long[]ip=newlong[4];
intposition1=strip.indexof(".");
intposition2=strip.indexof(".",position1+1);
intposition3=strip.indexof(".",position2+1);
ip[0]=long.parselong(strip.substring(0,position1));
ip[1]=long.parselong(strip.substring(position1+1,position2));
ip[2]=long.parselong(strip.substring(position2+1,position3));
ip[3]=long.parselong(strip.substring(position3+1));
return(ip[0]<<24)+(ip[1]<<16)+(ip[2]<<8)+ip[3];//ip1*256*256*256+ip2*256*256+ip3*256+ip4
}
privatestaticstringlongtoip(longlongip)
//将10进制整数形式转换成127.0.0.1形式的ip地址，在命令提示符下输入ping3396362403l
{
stringbuffersb=newstringbuffer("");
sb.append(string.valueof(longip>>>24));//直接右移24位
sb.append(".");
sb.append(string.valueof((longip&0x00ffffff)>>>16));//将高8位置0，然后右移16位
sb.append(".");
sb.append(string.valueof((longip&0x0000ffff)>>>8));
sb.append(".");
sb.append(string.valueof(longip&0x000000ff));
sb.append(".");
returnsb.tostring();
}
publicstaticvoidmain(string[]args)
{
system.out.println("ip地址的各种表现形式：rn");
system.out.print("32位二进制形式：");
system.out.println(long.tobinarystring(3396362403l));
system.out.print("十进制形式：");
system.out.println(iptolong("202.112.96.163"));
system.out.print("普通形式：");
system.out.println(longtoip(3396362403l));
}
}

publicclassIp{
publicstaticvoidmain(String[]args){
System.out.print(ip2int("10.0.3.193"));
}
publicstaticlongip2int(Stringip){
String[]items=ip.split(".");
returnLong.valueOf(items[0])<<24
|Long.valueOf(items[1])<<16
|Long.valueOf(items[2])<<8
|Long.valueOf(items[3]);
}
}

publicclassIp{
publicstaticvoidmain(String[]args){
System.out.print(int2ip(167773121));
}
publicstaticStringint2ip(longipInt){
StringBuildersb=newStringBuilder();
sb.append(ipInt&0xFF).append(".");
sb.append((ipInt>>8)&0xFF).append(".");
sb.append((ipInt>>16)&0xFF).append(".");
sb.append((ipInt>>24)&0xFF);
returnsb.toString();
}
}