PermissionCollection newPermissionCollection()
描述 (Description)
java.util.PropertyPermission.newPermissionCollection()方法创建并返回一个新的PermissionCollection对象。
声明 (Declaration)
以下是java.util.PropertyPermission.newPermissionCollection()方法的声明
public PermissionCollection newPermissionCollection()
参数 (Parameters)
NA
返回值 (Return Value)
此方法返回新创建的PermissionCollection对象。
异常 (Exception)
NA
例子 (Example)
以下示例显示了java.util.PropertyPermission.newPermissionCollection()方法的用法。
package com.iowiki;
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