ReflectUtil.java 文件源码

/**
 * Does a conservative approximation of member access check. Use this if
 * you don't have an actual 'userland' caller Class/ClassLoader available.
 * This might be more restrictive than a precise member access check where
 * you have a caller, but should never allow a member access that is
 * forbidden.
 *
 * @param m the {@code Member} about to be accessed
 */
public static void conservativeCheckMemberAccess(Member m) throws SecurityException{
    final SecurityManager sm = System.getSecurityManager();
    if (sm == null)
        return;

    // Check for package access on the declaring class.
    //
    // In addition, unless the member and the declaring class are both
    // public check for access declared member permissions.
    //
    // This is done regardless of ClassLoader relations between the {@code
    // Member m} and any potential caller.

    final Class<?> declaringClass = m.getDeclaringClass();

    checkPackageAccess(declaringClass);

    if (Modifier.isPublic(m.getModifiers()) &&
            Modifier.isPublic(declaringClass.getModifiers()))
        return;

    // Check for declared member access.
    sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION);
}