java后台如何生成邀请码

```java

import java.util.Random;

public class InviteCodeGenerator {

private static final String CHAR_SET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

private static final int CODE_LENGTH = 8;

public static String generateRandomCode() {

StringBuilder code = new StringBuilder();

Random random = new Random();

for (int i = 0; i < CODE_LENGTH; i++) {

int index = random.nextInt(CHAR_SET.length());

code.append(CHAR_SET.charAt(index));