import
java.util.Random; 
public
static
String getRandomString(
int
length)
...
{ 
StringBuffer buffer = new StringBuffer("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"); StringBuffer sb = new StringBuffer(); Random r = new Random(); int range = buffer.length(); 
for (int i = 0; i < length; i ++) ...{ sb.append(buffer.charAt(r.nextInt(range))); 
} return sb.toString(); 
}
仅供自己参考，代码写一遍，以后到哪里都能用。呵呵。。。
