import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.ByteOrder;

import java.util.Arrays;

class IP {

public static void main(String[] args){

IP.load("H:\\loveapp\\codebase\\17mon\\17monipdb.dat");

System.out.println(Arrays.toString(IP.find("8.8.8.8")));

System.out.println(Arrays.toString(IP.find("118.28.38.58")));

System.out.println(Arrays.toString(IP.find("255.255.255.255")));

}

private static int offset;

private static int[] index = new int[256];

private static ByteBuffer dataBuffer;

private static ByteBuffer indexBuffer;

public static void load(String filename) {

File ipFile = new File(filename);

final int fileLength = Long.valueOf(ipFile.length()).intValue();

dataBuffer = ByteBuffer.allocate(fileLength);

FileInputStream fin = null;

try {

fin = new FileInputStream(ipFile);

int readBytesLength;

byte[] chunk = new byte[4096];

while (fin.available() > 0) {

readBytesLength = fin.read(chunk);

dataBuffer.put(chunk, 0, readBytesLength);

}

dataBuffer.position(0);

int indexLength = dataBuffer.getInt();

byte[] indexBytes = new byte[indexLength];

dataBuffer.get(indexBytes, 0, indexLength - 4);

indexBuffer = ByteBuffer.wrap(indexBytes);

indexBuffer.order(ByteOrder.LITTLE_ENDIAN);

offset = indexLength;

int loop = 0;

while (loop++ < 256) {

index[loop - 1] = indexBuffer.getInt();

}

indexBuffer.order(ByteOrder.BIG_ENDIAN);

} catch (IOException ioe) {

//

} finally {

try {

if (fin != null) {

fin.close();

}

} catch (IOException e){

//

}

}

}

public static String[] find(String ip) {

int ip_prefix_value = new Integer(ip.substring(0, ip.indexOf(".")));

long ip2long_value = ip2long(ip);

int start = index[ip_prefix_value];

int max_comp_len = offset - 1028;

long tmpInt;

long index_offset = -1;

int index_length = -1;

byte b = 0;

for (start = start * 8 + 1024; start < max_comp_len; start += 8) {

tmpInt = int2long(indexBuffer.getInt(start));

if (tmpInt >= ip2long_value) {

index_offset = bytesToLong(b, indexBuffer.get(start + 6), indexBuffer.get(start + 5), indexBuffer.get(start + 4));

index_length = 0xFF & indexBuffer.get(start + 7);

break;

}

}

byte[] areaBytes;

synchronized (dataBuffer) {

dataBuffer.position(offset + (int) index_offset - 1024);

areaBytes = new byte[index_length];

dataBuffer.get(areaBytes, 0, index_length);

}

return new String(areaBytes).split("\t");

}

private static long bytesToLong(byte a, byte b, byte c, byte d) {

return int2long((((a & 0xff) << 24) | ((b & 0xff) << 16) | ((c & 0xff) << 8) | (d & 0xff)));

}

private static int str2Ip(String ip) {

String[] ss = ip.split("\\.");

int a, b, c, d;

a = Integer.parseInt(ss[0]);

b = Integer.parseInt(ss[1]);

c = Integer.parseInt(ss[2]);

d = Integer.parseInt(ss[3]);

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

}

private static long ip2long(String ip) {

return int2long(str2Ip(ip));

}

private static long int2long(int i) {

long l = i & 0x7fffffffL;

if (i < 0) {

l |= 0x080000000L;

}

return l;

}

}