SecurityManager類的checkMemberAccess()方法 (SecurityManager Class checkMemberAccess() method)

• checkMemberAccess() method is available in java.lang package.

  checkMemberAccess()方法在java.lang包中可用。

• In checkMemberAccess() method we access public members and classes that have similar class loaders like caller by default and in other cases, it calls checkPermission("accessDeclaredMembers") permission.

  在checkMemberAccess()方法中 ，默認情況下，我們訪問具有類似類加載器的公共成員和類，例如調用者，在其他情況下，它調用checkPermission(“ accessDeclaredMembers”)權限。

• checkMemberAccess() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  checkMemberAccess()方法是一個非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。

• checkMemberAccess() method may throw an exception at the time of accessing members.

  checkMemberAccess()方法在訪問成員時可能會引發異常。

  • SecurityException – This exception may throw when the calling thread does not have the right to access members.
  • NullPointerException – This exception may throw when the given first parameter is null.

Syntax:

句法：

    public void checkMemberAccess(Class cl, int type);

Parameter(s):

參數：

• Class cl – represents the class that indication is to be operated on.

  cl類 –表示要對其進行操作的類。

• int type – represents the access type like PUBLIC OR DECLARED.

  int type –表示訪問類型，例如PUBLIC或DECLARED。

Return value:

返回值：

The return type of this method is void, it returns nothing.

此方法的返回類型為void ，不返回任何內容。

Example:

例：

// Java program to demonstrate the example 
// of void checkMemberAccess(Class cl, int type)
// method of SecurityManager 
import java.lang.reflect.*;
public class CheckMemberAccess extends SecurityManager {
public void checkMemberAccess(Class cl, int type) {
throw new SecurityException("Restricted..");
}
public static void main(String[] args) {
// By using setProperty() method is to set the policy property 
// with security manager
System.setProperty("java.security.policy", "file:/C:/java.policy");
// Instantiating a CheckMemberAccess object
CheckMemberAccess cma = new CheckMemberAccess();
// By using setSecurityManager() method is to set the
// security manager
System.setSecurityManager(cma);
// By using checkMemberAccess(Class,type) method is to check 
// accessibility of the member
cma.checkMemberAccess(CheckMemberAccess.class, Member.DECLARED);
// Display the message
System.out.println("Not Restricted..");
}
}

Output

輸出量

Exception in thread "main" java.lang.SecurityException: Restricted..at CheckMemberAccess.checkMemberAccess(CheckMemberAccess.java:9)at CheckMemberAccess.main(CheckMemberAccess.java:27)

翻譯自: https://www.includehelp.com/java/securitymanager-checkmemberaccess-method-with-example.aspx