The Java Tutorials have been written for JDK 8.Java教程是为JDK 8编写的。Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.本页中描述的示例和实践没有利用后续版本中引入的改进，并且可能使用不再可用的技术。See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.有关Java SE 9及其后续版本中更新的语言特性的摘要，请参阅Java语言更改。
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.有关所有JDK版本的新功能、增强功能以及已删除或不推荐的选项的信息，请参阅JDK发行说明。
The JAXP properties will be checked first before a connection is attempted whether or not a SecurityManager is present. This means that a connection may be blocked even if it is granted permission by the SecurityManager. For example, if the JAXP properties are set to disallow the http protocol, they will effectively block any connection attempt even when an application has SocketPermission.
For the purpose of restricting connections, the SecurityManager can be views as being at a lower level. Permissions will be checked after the JAXP properties are evaluated. If an application does not have SocketPermission for example, then a SecurityException will be thrown even if the JAXP properties are set to allow a http connection.
When SecurityManager is present, the JAXP FEATURE_SECURE_PROCESSING is set to true. This behavior will not turn on the new restrictions.