问题描述
我有一个名为 Student 的对象，它有 studentName、studentId、studentAddress 等.studentId，我必须生成由七个数字字符组成的随机字符串，例如.
I have an object called Student, and it has studentName, studentId, studentAddress, etc. For the studentId, I have to generate random string consist of seven numeric charaters,
eg.
studentId = getRandomId();
studentId = "1234567" <-- from the random generator.
而且我必须确保没有重复的 id.
And I have to make sure that there is no duplicate id.
推荐答案
生成一个随机字符串很容易 - 只需使用 java.util.Random 和一个包含您想要的所有字符的字符串可用，例如
Generating a random string of characters is easy - just use java.util.Random and a string containing all the characters you want to be available, e.g.
public static String generateString(Random rng, String characters, int length)
{
char[] text = new char[length];
for (int i = 0; i < length; i++)
{
text[i] = characters.charAt(rng.nextInt(characters.length()));
}
return new String(text);
}
现在，为了唯一性，您需要将生成的字符串存储在某处.您如何做到这一点实际上取决于您的应用程序的其余部分.
Now, for uniqueness you'll need to store the generated strings somewhere. How you do that will really depend on the rest of your application.
这篇关于如何在 Java 中生成随机字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！