java.lang.Class类的cast()方法用于将指定的对象强制转换为此类的对象。该方法以对象形式转换后返回对象。
用法:
public T[] cast(Object obj)
参数:此方法接受参数obj,它是要转换的对象
返回值:此方法以对象形式转换后返回指定的对象。
异常:该方法抛出:
- ClassCastException:如果对象不为null,并且不能分配给T类型。
下面的程序演示了cast()方法。
范例1:
// Java program to demonstrate
// cast() method
import java.util.*;
public class Test {
public static Object obj;
public static void main(String[] args)
throws ClassNotFoundException
{
// returns the Class object for this class
Class myClass = Class.forName("Test");
System.out.println("Class represented by myClass:"
+ myClass.toString());
// Cast the object obj to object of myClass
// using cast() method
System.out.println("Object " + obj + " after cast "
+ "upon to class Test:"
+ myClass.cast(obj));
}
}
输出:
Class represented by myClass:class Test Object null after cast upon to class Test:null
范例2:
// Java program to demonstrate
// cast() method
import java.util.*;
class Main {
private static int obj = 10;
public static void main(String[] args)
throws ClassNotFoundException
{
try {
// returns the Class object for this class
Class myClass = Class.forName("Main");
System.out.println("Class represented by myClass:"
+ myClass.toString());
// Cast the object obj to object of myClass
// using cast() method
System.out.println("Object " + obj + " after cast "
+ "upon to class Test:"
+ myClass.cast(obj));
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
Class represented by myClass:class Main java.lang.ClassCastException:Cannot cast java.lang.Integer to Main
参考: https://docs.oracle.com/javase/9/docs/api/java/lang/Class.html#cast-java.lang.Object-
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注:本文由纯净天空筛选整理自srinam大神的英文原创作品 Class cast() method in Java with Examples。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。