在基本Java类中不可见的变量

Question

我正在尝试构建一个ArrayList of Earthquake对象，但是Earthquake抱怨说它不可见。

我的守则：

import java.io.*;
import java.util.Arrays.*;

public class ObservatoryTest {
    private ArrayList <Earthquakes> listOfEarthquakes; //This list is not visible
    Earthquakes Quake1 = new Earthquakes(4.5,"cheese",1995);
    Earthquakes Quake2 = new Earthquakes(6.5,"fish",1945);
    Earthquakes Quake3 = new Earthquakes(10.5,"Chorizo",2015);

    public void buildList(Earthquakes... args){
        for(Earthquakes myEarthquake : args){
            listOfEarthquakes.add(myEarthquake);
        }

    }
}

我的目标是建立一个地震对象的清单。有人能告诉我为什么以及如何修正我的代码吗？谢谢

？？编辑？？编辑？

错误消息是the type ArrayList is not visible，但是将可见性修饰符更改为public没有任何效果。

Answer 1

缺少以下导入语句

 import java.util.ArrayList;

 public class ObservatoryTest {

 private ArrayList <Earthquakes> listOfEarthquakes; //This list is not visible
    Earthquakes Quake1 = new Earthquakes(4.5,"cheese",1995);
    Earthquakes Quake2 = new Earthquakes(6.5,"fish",1945);
    Earthquakes Quake3 = new Earthquakes(10.5,"Chorizo",2015);

    public void buildList(Earthquakes... args){
        for(Earthquakes myEarthquake : args){
            listOfEarthquakes.add(myEarthquake);
        }

    }

Answer 2

出于某种原因，您已经将输入按需申报用于Arrays的嵌套成员

import java.util.Arrays.*;

在当前的实现中，Arrays声明了一个名为ArrayList的private嵌套类型。这在代码中是不可见的，因为它是private。

您的意思是导入java.util.ArrayList。

Answer 3

您缺少了ArrayList的导入语句

import java.util.ArrayList;

要解决这些问题，请调用SDE的“组织导入”。在Eclipse中:Ctrl O