当我尝试编译时，出现错误:
cannot make a static reference to the non-static method getId() from the type Doctor.
Doctor 是Staff 的子类。当我在代码中将 Doctor 替换为 Staff 时，出现同样的错误。我知道我不能用父类(super class)替换子类，所以这就是为什么 Staff 不起作用，但在我的 Database 类中，我没有声明任何内容作为静态，所以我不明白为什么或如何它是静态的以及为什么我会收到该错误。
这是我的数据库类
import java.util.ArrayList;
public class Database
{
String id;
private ArrayList<Staff> staff;
/**
* Construct an empty Database.
*/
public Database()
{
staff = new ArrayList<Staff>();
}
/**
* Add an item to the database.
* @param theItem The item to be added.
*/
public void addStaff(Staff staffMember)
{
staff.add(staffMember);
}
/**
* Print a list of all currently stored items to the
* text terminal.
*/
public void list()
{
for(Staff s : staff) {
s.print();
System.out.println(); // empty line between items
}
}
public void printStaff()
{
for(Staff s : staff){
id = Doctor.getId();//This is where I'm getting the error.
if(true)
{
s.print();
}
}
}
这是我的员工类(class)。
public class Staff
{
private String name;
private int staffNumber;
private String office;
private String id;
/**
* Initialise the fields of the item.
* @param theName The name of this member of staff.
* @param theStaffNumber The number of this member of staff.
* @param theOffice The office of this member of staff.
*/
public Staff(String staffId, String theName, int theStaffNumber, String theOffice)
{
id = staffId;
name = theName;
staffNumber = theStaffNumber;
office = theOffice;
}
public String getId()
{
return this.id;
}
/**
* Print details about this member of staff to the text terminal.
*/
public void print()
{
System.out.println("ID: " + id);
System.out.println("Name: " + name);
System.out.println("Staff Number: " + staffNumber);
System.out.println("Office: " + office);
}
}
最佳答案
您调用该方法就好像它是静态的一样，因为您使用类名调用它:Doctor.getId()。
您需要一个 Doctor 类的实例来调用实例方法。
也许您打算在循环中的 s(Staff 实例)上调用 getId？
关于java - 收到 "cannot make a static reference to the non-static method"错误，但我尚未将调用的方法声明为静态，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12712234/