類類forName()方法 (Class class forName() method)
forName() method is available in java.lang package.
forName()方法在java.lang包中可用。
forName() method is used to return the class object for the Class with the given class_name.
forName()方法用于返回具有給定class_name的Class的類對象。
forName() method is a static method, it is accessible with the class name and if we try to access the method with the class object then we will not get any error.
forName()方法是一個靜態方法，可以使用類名進行訪問，如果嘗試使用類對象訪問該方法，則不會出現任何錯誤。
forName() method may throw an exception at the time of returning a Class object.
forName()方法在返回Class對象時可能會引發異常。
- LinkageError: This exception may throw when we get linking error.LinkageError ：當我們獲得鏈接錯誤時，可能會拋出此異常。
- ExceptionInInitializeError: In this exception when the initialization is done by this method fails.ExceptionInInitializeError ：在此方法中，初始化失敗的此異常。
- ClassNotFoundException: In this exception when the given class does not exist.ClassNotFoundException ：如果給定的類不存在，則在此異常中。
Syntax:
句法：
public static Class forName(String class_name);
Parameter(s):
參數：
String class_name – represents the fully qualified name of the given class.
字符串class_name –代表給定類的完全限定名稱。
Return value:
返回值：
The return type of this method is Class, it returns this Class object for the class with the given name.
該方法的返回類型為Class ，它將為具有給定名稱的類返回此Class對象。
Example:
例：
// Java program to demonstrate the example
// of Class forName (String class_name) method of Class
public class ForNameOfClass {
public static void main(String[] args) throws Exception {
// It returns the Class 'java.lang.Object' object for the class
// with the given class name
Class cl = Class.forName("java.lang.Object");
// Display Name, Package and Interfaces
System.out.print("Class 'java.lang.Object' Name: ");
System.out.println(cl.getName());
System.out.print("Class 'java.lang.Object' Package: ");
System.out.println(cl.getPackage());
System.out.print("Class 'java.lang.Object' Interface: ");
System.out.println(cl.getInterfaces());
}
}
Output
輸出量
Class 'java.lang.Object' Name: java.lang.Object
Class 'java.lang.Object' Package: package java.lang
Class 'java.lang.Object' Interface: [Ljava.lang.Class;@68f7aae2
翻譯自: https://www.includehelp.com/java/class-class-forname-method-with-example.aspx
