封装各种生成唯一性ID算法的工具类.

package com.westcredit.common.utils;

import java.io.Serializable;
import java.security.SecureRandom;
import java.util.UUID;

import org.apache.shiro.session.Session;
import org.apache.shiro.session.mgt.eis.SessionIdGenerator;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * @author westcredit
 * @version 2013-01-15
 */
@Service
@Lazy(false)
public class IdGen implements  SessionIdGenerator {

private static SecureRandom random = new SecureRandom();

/**
* 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
*/
public static String uuid() {
return UUID.randomUUID().toString().replaceAll("-", "");
}

/**
* 使用SecureRandom随机生成Long. 
*/
public static long randomLong() {
return Math.abs(random.nextLong());
}

/**
* 基于Base62编码的SecureRandom随机生成bytes.
*/
public static String randomBase62(int length) {
byte[] randomBytes = new byte[length];
random.nextBytes(randomBytes);
return Encodes.encodeBase62(randomBytes);
}

@Override
public Serializable generateId(Session session) {
return IdGen.uuid();
}

public static void main(String[] args) {
System.out.println(IdGen.uuid());
System.out.println(IdGen.uuid().length());
for (int i=0; i<1000; i++){
System.out.println(IdGen.randomLong() + "  " + IdGen.randomBase62(5));
}
}

}