随机ID

指定长度随机数字和字母字符串
public static String getStringRandom(int length) {
String val = "";
Random random = new Random();
// 参数length，表示生成几位随机数
for (int i = 0; i < length; i++) {
String charOrNum = random.nextInt(2) % 2 == 0 ? "char" : "num";
// 输出字母还是数字
if ("char".equalsIgnoreCase(charOrNum)) {
// 输出是大写字母还是小写字母
int temp = random.nextInt(2) % 2 == 0 ? 65 : 97;
val += (char) (random.nextInt(26) + temp);
} else if ("num".equalsIgnoreCase(charOrNum)) {
val += String.valueOf(random.nextInt(10));
}
}
return val;
}

指定长度随机数字
public static String getOnlyNumRandom(int length) {
String val = "";
Random random = new Random();
for (int i = 0; i < length; i++) {
val += String.valueOf(random.nextInt(10));
}
return val;
}