package test;

public class RegexTest {
    public static void main(String[] args) {
        String regex = "^[a-zA-Z][a-zA-Z1-9]*$";  
        String testString = "Abc123"; // 测试字符串  
        
        boolean matches = testString.matches(regex);  
        
        if (matches) {  
            System.out.println("字符串仅由字母和数字（1-9）组成");  
        } else {  
            System.out.println("字符串包含非字母或非数字（1-9）的字符");  
        }
    }
}