Guava – Shorts.toArray()方法及实例
Guava库中Shorts类的toArray()方法是用来将作为参数传递给该方法的短值转换成短数组。这些短值被作为一个集合传递给这个方法。该方法返回一个短数组。
语法:
public static short[] toArray(Collection extends Number>collection?>)
参数: 这个方法接受一个强制性的参数集合,它是要转换为短数组的短值集合。
返回值: 该方法返回一个短数组,包含与集合相同的值,顺序相同。
异常情况:如果传递的集合或其任何元素为空,该方法会抛出NullPointerException。
以下程序说明了toArray()方法的使用。
例1:
// Java code to show implementation of
// Guava's Shorts.toArray() method
import com.google.common.primitives.Shorts;
import java.util.Arrays;
import java.util.List;
class GFG {
// Driver's code
public static void main(String[] args)
{
// Creating a List of Shorts
List<Short> myList
= Arrays.asList((short)1, (short)2,
(short)3, (short)4, (short)5);
// Using Shorts.toArray() method to convert
// a List or Set of Short to an array of Short
short[] arr = Shorts.toArray(myList);
// Displaying an array containing each
// value of collection,
// converted to a short value
System.out.println(Arrays.toString(arr));
}
}
输出:
[1, 2, 3, 4, 5]
例2:
// Java code to show implementation of
// Guava's Shorts.toArray() method
import com.google.common.primitives.Shorts;
import java.util.Arrays;
import java.util.List;
class GFG {
// Driver's code
public static void main(String[] args)
{
try {
// Creating a List of Shorts
List<Short> myList
= Arrays.asList((short)2,
(short)4, null);
// Using Shorts.toArray() method
// to convert a List or Set of Short
// to an array of Short.
// This should raise "NullPointerException"
// as the collection contains "null"
// as an element
short[] arr = Shorts.toArray(myList);
// Displaying an array containing each
// value of collection,
// converted to a short value
System.out.println(Arrays
.toString(arr));
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
java.lang.NullPointerException
参考资料:
https://google.github.io/guava/releases/23.0/api/docs/com/google/common/primitives/Shorts.html#toArray-java.util.Collection-