主键生成器
package com.appdev.bsf.fusioncharts.client;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Date;
/**
* 主键生成器。该类使用单例模式。
*
*/
public class PKGenerator {
/**
* �存储主机IP左移48位后的值。ֵ��
*
*/
private long key;
private static final PKGenerator instance = new PKGenerator();
/**
* 获得当前主机IP的后3位（如192.168.0.112中的112），左移48位后存入变量lastTransIP中������ l
*
* @roseuid 3EF6A8F0023D
*/
private PKGenerator() {
try {
InetAddress ia = InetAddress.getLocalHost();
String strIP = ia.getHostAddress();
int lastPoint = strIP.lastIndexOf(".");
int longip = Integer.parseInt(strIP.substring(lastPoint + 1));
makeKey(longip);
} catch (UnknownHostException e) {
System.out.println("No Host");
}
}
/**
* 生成key
*
* @param seed
*/
private synchronized void makeKey(int seed) {
long lastTransIP = ((long) seed) << 48;
Date date = new Date();
long longTime = date.getTime();
key = longTime | lastTransIP;
}
/**
* @return com.adtech.util.PKGenerator
* @roseuid 3EF6A8F00251
*
*/
public static PKGenerator getInstance() {
return instance;
}
/**
* 返回唯一的键。获得当前时间的毫秒数位与lastTransIP的值。ֵ��
*
* @return long
* @roseuid 3EF6A8F00265
*
*/
private synchronized long getKey() {
return ++key;
}
public long generateKey() {
return instance.getKey();
}
}