....不在公共领域;无法从外部访问包

Question

我正在写一个简单的按钮，单击时会创建一个新的联系人。我知道这个错误发生是由于公共宣传与私人宣言，但我无法弄清楚发生了什么。我已经输入了接触的类，但我被卡住了。

import java.util.*; 


class Contact { 

private List<Contact> contacts = new LinkedList<Contact>(); 
private int nextId = 0; 

public Contact add(Contact contact) { 
    contact.setId(++nextId); 
    contacts.add(contact); 
    return contact; 
} 
private String firstName = ""; 
private String lastName = ""; 
private String email = ""; 

下面是代码调用接触

import domain.*; 
import javax.swing.JOptionPane; 

public class MainUI extends javax.swing.JFrame { 

private Account account = null; 

public void setAccount(Account account) { 
    this.account = account; 
} 


Contact contact = new Contact(); // Error is here 
    contact.setFirstname(firstNameFld.getText()); 
    contact.setLastname(lastNameFld.getText()); 
    contact.setEmail(emailFld.getText()); 
    contact.setPhone(phoneFld.getText()); 

    boolean isValid = contact.validate(); 
    if(!isValid) { 
     JOptionPane.showMessageDialog(this, "All fields are required for a Contact", "Error", JOptionPane.ERROR_MESSAGE); 
    return; 
    } 
    JOptionPane.showMessageDialog(this, "Your new Contact has been saved", "Saved Contact", JOptionPane.INFORMATION_MESSAGE); 
    firstNameFld.setText(""); 
    lastNameFld.setText(""); 
    emailFld.setText(""); 
    phoneFld.setText(""); 
}           

Answer 1

你接触类是包私有，将其改为公开或移动类同一个包。