java UUID

import java.util.UUID;

public class TestMain {

	public static void main(String[] args) {
		String str = UUID.randomUUID().toString();
		System.out.println(str);
		System.out.println(str.length());
		
		str = str.replace("-", "");
		System.out.println(str);
		System.out.println(str.length());
	}
}

执行结果：

1e9704ad-61fc-424a-a32c-ae3f96c48e4a
36
1e9704ad61fc424aa32cae3f96c48e4a
32