使用Collections.nCopies()和Collections.fill()實現對容器的簡單填充。
具體代碼如下:
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class FillingLists {
public static void main(String[] args) {
List<StringAddress> list = new ArrayList<StringAddress>(
Collections.nCopies(3, new StringAddress("Hello")));
System.out.println(list);
Collections.fill(list, new StringAddress("World"));
System.out.println(list);
}
}
class StringAddress {
private String s;
public StringAddress(String s) {
super();
this.s = s;
}
public String toString() {
return super.toString() + " " + s;
}
}
運行結果截圖:
簡單分析:
Collections.nCopies()只能在創建List時來填充容器,Collections.fill()是用來對一個已有容器的填充,可以更形象地理解爲重置。