Java的.nio.file.LinkPermission类在Java中

Java.nio.file.LinkPermission 类处理链接创建操作的权限。这些类允许的权限如下：

Permission name	What permission allows	Risk of granting this permission
hard	This permission allows adding an existing file to a directory. This operation is also known as creating a hard link.	The attacker may have access to all files because this permission allows linking to any file in the file system.
symbolic	This permission allows creating file pointers. This operation is also known as creating soft/symbolic link.	The attacker may have access to all files because this permission allows linking to any file in the file system.

类声明：

public final class LinkPermission
extends BasicPermission

构造函数：

Constructor	Description
LinkPermission(String name)	This constructor is used to create a LinkPermission with the specified name.
LinkPermission(String name, String actions)	This constructor is used to create a LinkPermission with the specified name and action.

从类Java.security.BasicPermission 继承的方法：

Method	Description
equals(Object obj)	This method checks whether the two BasicPermission objects are equal or not
getActions()	This method returns the actions in String format
hashCode()	This method returns the hash code value for this object
implies(Permission permission)	This method checks whether the given permission is implied by this object or not
newPermissionCollection()	This method returns a new PermissionCollection object

示例1： Java程序创建新的硬LinkPermission

Java

// Java program to create a new hard LinkPermission
import java.nio.file.LinkPermission;
import java.security.Permission;
  
// Driver class
public class GFG {
    // Main method
    public static void main(String[] args)
    {
        try {
            // Creating a new LinkPermisson object
            Permission permission
                = new LinkPermission("hard");
            
            // Printing name of the permission
            System.out.println(permission.getName());
            
            // Printing class of the permission object
            System.out.println(permission.getClass());
            
            // Printing hash value of the permission object
            System.out.println(permission.hashCode());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

输出

hard
class java.nio.file.LinkPermission
3195115

示例 2： Java程序创建新的符号 LinkPermission

Java

// Java program to create a new symbolic LinkPermission
import java.nio.file.LinkPermission;
import java.security.Permission;
  
// Driver class
public class GFG {
    // Main method
    public static void main(String[] args)
    {
        try {
            
            // Creating a new LinkPermisson object
            Permission permission
                = new LinkPermission("symbolic");
            
            // Printing name of the permission
            System.out.println(permission.getName());
            
            // Printing class of the permission object
            System.out.println(permission.getClass());
            
            // Printing hash value of the permission object
            System.out.println(permission.hashCode());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

输出

symbolic
class java.nio.file.LinkPermission
1787985074

示例 3：比较两个 LinkPermission 对象的Java程序

Java

// Java program to compare two LinkPermission objects
import java.nio.file.LinkPermission;
import java.security.Permission;
  
// Driver class
public class GFG {
    // Main method
    public static void main(String[] args)
    {
        try {
  
            Permission hardPermission
                = new LinkPermission("hard");
            Permission softPermission
                = new LinkPermission("symbolic");
            
            // Checking is both permissions are equal or not
            if (hardPermission.equals(softPermission)) {
                System.out.println(
                    "Both permission are equal");
            }
            else {
                System.out.println(
                    "Both permission are not equal");
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

输出

Both permission are not equal