Java中的类 getProtectionDomain() 方法和示例

Java.lang.Class 类的getProtectionDomain()方法用于获取该类的ProtectionDomain。该方法以ProtectionDomain 对象的形式返回该类的指定ProtectionDomain。

句法：

public ProtectionDomain getProtectionDomain()

参数：此方法不接受任何参数

返回值：该方法以ProtectionDomain对象的形式返回该类的指定ProtectionDomain 。

异常此方法抛出：

• 如果安全管理器存在且其 checkPermission 方法不允许获取 ProtectionDomain，则出现 SecurityException。

下面的程序演示了 getProtectionDomain() 方法。

示例 1：

// Java program to demonstrate
// getProtectionDomain() method
  
import java.util.*;
  
public class Test {
  
    public Object obj;
  
    public static void main(String[] args)
        throws ClassNotFoundException
    {
  
        try {
  
            // returns the Class object for this class
            Class myClass = Class.forName("Test");
  
            System.out.println("Class represented by myClass: "
                               + myClass.toString());
  
            // Get the ProtectionDomain of myClass
            // using getProtectionDomain() method
            System.out.println("ProtectionDomain of myClass: "
                               + myClass.getProtectionDomain());
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

Class represented by myClass: class Test
java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "getProtectionDomain")

示例 2：

// Java program to demonstrate
// getProtectionDomain() method
  
import java.util.*;
  
class Main {
  
    private Object obj;
  
    public static void main(String[] args)
        throws ClassNotFoundException, NoSuchFieldException
    {
  
        try {
            // returns the Class object for this class
            Class myClass = Class.forName("Main");
  
            System.out.println("Class represented by myClass: "
                               + myClass.toString());
  
            String ProtectionDomainName = "obj";
  
            // Get the ProtectionDomain of myClass
            // using getProtectionDomain() method
            System.out.println("ProtectionDomain of myClass: "
                               + myClass.getProtectionDomain());
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

Class represented by myClass: class Main
java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "getProtectionDomain")

参考： https://docs.oracle.com/javase/9/docs/api/ Java/lang/Class.html#getProtectionDomain–