我试图调用BasicInfo类中的方法（全名（），alsoKnownAs（））到另一个名为Customer的类中，特别是在displayInfo（）部分，但不确定如何做到这一点，下面是我的代码：

enum Gender {MALE, FEMALE}

class BasicInfo
{
    private String firstName, secondName, lastName;
    private Gender g;
    
    //Default Constructor
    public BasicInfo()
    {
        //Do nothing
    }
    
    //Other Constructor
    public BasicInfo(String firstName, String secondName, String lastName, Gender g)
    {
        this.firstName = firstName;
        this.secondName = secondName;
        this.lastName = lastName;
        this.g = g;
    }
    
    //Copy Constructor
    public BasicInfo(BasicInfo bi)
    {
        this.firstName = bi.firstName;
        this.secondName = bi.secondName;
        this.lastName = bi.lastName;
        this.g = bi.g;
    }
    
    public String getFirstName()
    {
        return firstName;
    }
    
    public String getSecondName()
    {
        return secondName;
    }
    
    public String getLastName()
    {
        return lastName;
    }
    
    private Gender getGender()
    {
        return g;
    }
    
    public void setInfo(String firstName, String secondName, String lastName, Gender g)
    {
        this.firstName = firstName;
        this.secondName = secondName;
        this.lastName = lastName;
        this.g = g;
    }
    
    private String fullName()
    {
        return (firstName + " " + secondName + " " + lastName);
    }
    
    private String alsoKnownAs()
    {
        return (firstName.charAt(0) + ". " + secondName.charAt(0) + ". " + lastName);
    }
    
    public void displayInfo()
    {
        System.out.printf("Full name: %s%n", fullName());
        System.out.printf("Also known as: %s%n", alsoKnownAs());
        System.out.printf("Gender: %s%n", getGender());
    }
}

class Customer
{
    private BasicInfo bi;
    private int birthYear;
    
    public Customer()
    {
        //Do nothing
    }
    
    public Customer(BasicInfo bi, int birthYear)
    {
        this.bi = bi;
        this.birthYear = birthYear;
    }
    
    public Customer(Customer c)
    {
        this.bi = c.bi;
        this.birthYear = c.birthYear;
    }
    
    public BasicInfo getBasicInfo()
    {
        return bi;
    }
    
    public int getBirthYear()
    {
        return birthYear;
    }
    
    public void setInfo(BasicInfo bi, int birthYear)
    {
        this.bi = bi;
        this.birthYear = birthYear;
    }
    
    public void displayInfo()
    {
        System.out.printf("Full name: %s%n", bi.fullName());
        System.out.printf("Also known as: %s%n", bi.alsoKnownAs());
        System.out.printf("Gender: %s%n", bi.getGender());
        System.out.printf("Year of birth: %d%n", birthYear);
    }
}

在客户类displayInfo（）中，我使用了“bi.fullName（）”和“bi.alsoKnownAs（）”和“bi.getGender（）"，这是方法调用的正确方式吗？如有任何帮助，我们将不胜感激：）
我也尝试使用“BasicInfo.'the method'"，但仍然导致编译错误。