我们被分配将文本文件转换为几何对象的数组列表。问题是我不知道我是把它转换成ArrayList还是只是实例化一个对象? Eclipse 声称我没有使用过 ArrayList 库
文本文件看起来像这样:
圆形,红色,假,4.0
圆形,蓝色,真实,2.0
圆形,蓝色,真实,10.0
矩形,黄色,true,10.0,6.0
矩形,绿色,true,5.0,11.0
矩形,红色,true,20.0,15.0
到目前为止,我已经用我的代码完成了此操作:
public class Driver {
public static void main(String[] args) throws FileNotFoundException {
GeometricObject g = null;
File diskFile = new File("e:/temp/obj.txt");
Scanner diskScanner = new Scanner(diskFile);
while (diskScanner.hasNext()) {
String list = diskScanner.nextLine();
g = recreateObject(list);
}
diskScanner.close();
}
private static GeometricObject recreateObject(String list) {
String[] data = list.split(",");
String geoObject = data[0];
if (geoObject.equals("Circle")) {
String color = data[1];
boolean filled = Boolean.valueOf(data[2]);
double radius = Double.valueOf(data[3]);
return new Circle(color, filled, radius);
}
if (geoObject.equals("Rectangle")) {
String color = data[1];
boolean filled = Boolean.valueOf(data[2]);
double length = Double.valueOf(data[3]);
double width = Double.valueOf(data[4]);
return new Rectangle(color, filled, length, width);
}
return null;
}
}
我想将每个 GeometricObject 存储到“ArrayList list = new ArrayList();”中[尚未实现]但我不知道该怎么做。
最佳答案
只需在 while 循环之外声明 ArrayList,然后在循环内添加新对象 g...
List<GeometricObject> geoList = new ArrayList<GeometricObject>();
while(diskScanner.hasNext()){
String list = diskScanner.nextLine();
g = recreateObject(list);
geoList.add(g);
}
关于java - 当我想从文件创建 ArrayList 时,我是否要从文件实例化对象? java ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28586758/