Java.util.PropertyPermission.newPermission Collection() Java.util.PropertyPermission.implies() Java.util.PropertyResourceBundle.getKeys() 描述 所述java.util.PropertyPermission.newPermissionCollection()方法创建并返回一个新的PermissionCollection对象。 声明 以下是java.util.PropertyPermission.newPermissionCollection()方法的声明 public PermissionCollection newPermissionCollection() 参数 NA 返回值 此方法返回新创建的PermissionCollection对象。 异常 NA 实例 以下示例显示了java.util.PropertyPermission.newPermissionCollection()方法的用法。 package com.tutorialspoint; import java.security.PermissionCollection; import java.util.PropertyPermission; public class PropertyPermissionDemo { private static PermissionCollection permissions; public static void main(String[] args) { // Build property permissions collection PropertyPermission permission = new PropertyPermission("java.*", "read"); permissions = permission.newPermissionCollection(); permissions.add(permission); permissions.add(new PropertyPermission("java.home.*", "read,write")); // Check permissions checkFileReadPermission("java.home"); checkFileWritePermission("java.home"); checkFileReadPermission("java.home.usr"); checkFileWritePermission("java.home.usr"); } private static void checkFileReadPermission(String path) { // Check permission on read action if(permissions.implies(new PropertyPermission(path, "read"))) { System.out.println("Has permissions on "+path+" for read"); } } private static void checkFileWritePermission(String path) { // Check permission on read action if(permissions.implies(new PropertyPermission(path, "write"))) { System.out.println("Has permissions on "+path+" for write"); } } } 让我们编译并运行上面的程序,这将产生以下结果 Has permissions on java.home for read Has permissions on java.home.usr for read Has permissions on java.home.usr for write Java.util.PropertyPermission.implies() Java.util.PropertyResourceBundle.getKeys()