您可以使用正则表达式来校验文件名和邮箱地址。以下是对应的代码示例：

校验文件名：

import java.util.regex.Matcher;  
import java.util.regex.Pattern;  
public class FileNameValidator {  
    public static void main(String[] args) {  
        String fileName = "test.txt";  
        boolean isValid = validateFileName(fileName);  
        System.out.println(fileName + " is valid: " + isValid);  
    }  
    public static boolean validateFileName(String fileName) {  
        String regex = "^[\\w-]+\\.[\\w]+$";  
        Pattern pattern = Pattern.compile(regex);  
        Matcher matcher = pattern.matcher(fileName);  
        return matcher.matches();  
    }  
}  

校验邮箱地址：

import java.util.regex.Matcher;  
import java.util.regex.Pattern;  
public class EmailValidator {  
    public static void main(String[] args) {  
        String email = "test@example.com";  
        boolean isValid = validateEmail(email);  
        System.out.println(email + " is valid: " + isValid);  
    }  
    public static boolean validateEmail(String email) {  
        String regex = "^\\w+([-+.']\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$";  
        Pattern pattern = Pattern.compile(regex);  
        Matcher matcher = pattern.matcher(email);  
        return matcher.matches();  
    }  
}  

您可以根据需要调用相应的方法进行校验。