Package java.nio.file

定义Java虚拟机访问文件，文件属性和文件系统的接口和类。

See: 描述

接口摘要

接口	描述
CopyOption	配置如何复制或移动文件的对象。
DirectoryStream<T>	一个对象来迭代目录中的条目。
DirectoryStream.Filter<T>	由对象执行的接口，用于确定是否应接受或过滤目录条目。
FileVisitor<T>	文件访问者
OpenOption	配置如何打开或创建文件的对象。
Path	可用于在文件系统中定位文件的对象。
PathMatcher	由对路径执行匹配操作的对象实现的接口。
SecureDirectoryStream<T>	A DirectoryStream ，它定义了相对于打开目录定位的文件的操作。
Watchable	可以注册到手表服务的对象，以便可以 观看更改和事件。
WatchEvent<T>	一个事件或一个重复的事件，一个对象注册了一个WatchService 。
WatchEvent.Kind<T>	一种事件类型，用于识别。
WatchEvent.Modifier	事件修饰符，用于量化如何Watchable与注册WatchService 。
WatchKey	表示的登记令牌watchable对象与WatchService 。
WatchService	监视注册对象进行更改和事件的监视服务。

类摘要

类	描述
Files	该类只包含对文件，目录或其他类型文件进行操作的静态方法。
FileStore	文件存储
FileSystem	提供文件系统的接口，并且是工厂用于访问文件系统中的文件和其他对象的对象。
FileSystems	文件系统的工厂方法。
LinkPermission	用于链接创建操作的 Permission类。
Paths	该类完全由返回一个静态方法Path通过转换路径字符串或URI 。
SimpleFileVisitor<T>	具有默认行为的简单文件访问者访问所有文件并重新抛出I / O错误。
StandardWatchEventKinds	定义 标准事件种类。

枚举摘要

Enum	描述
AccessMode	定义用于测试文件可访问性的访问模式。
FileVisitOption	定义文件树遍历选项。
FileVisitResult	结果类型为FileVisitor 。
LinkOption	定义如何处理符号链接的选项。
StandardCopyOption	定义标准复制选项。
StandardOpenOption	定义标准的开放选项。

异常摘要

异常	描述
AccessDeniedException	文件系统操作被拒绝时引发的检查异常，通常是由于文件权限或其他访问检查。
AtomicMoveNotSupportedException	当文件不能作为原子文件系统操作移动时，检查的异常抛出。
ClosedDirectoryStreamException	尝试在关闭的目录流上调用操作时抛出未检查的异常。
ClosedFileSystemException	尝试在文件上调用操作并关闭文件系统时抛出未检查的异常。
ClosedWatchServiceException	尝试在关闭的手表服务上调用操作时抛出未检查的异常。
DirectoryIteratorException	如果在遍历目录中的条目时遇到I / O错误，则抛出运行时异常。
DirectoryNotEmptyException	由于目录不为空，文件系统操作失败时抛出的检查异常。
FileAlreadyExistsException	尝试创建文件或目录并且该名称的文件已存在时，检查的异常抛出。
FileSystemAlreadyExistsException	尝试创建已存在的文件系统时抛出运行时异常。
FileSystemException	在一个或两个文件上的文件系统操作失败时抛出。
FileSystemLoopException	当遇到文件系统循环或循环时抛出的检查异常。
FileSystemNotFoundException	无法找到文件系统时抛出的运行时异常。
InvalidPathException	当路径字符串不能转换为Path因为路径字符串包含无效字符或路径字符串对于其他文件系统特定的原因无效时，将抛出未检查的异常。
NoSuchFileException	当尝试访问不存在的文件时抛出检查的异常。
NotDirectoryException	当文件系统操作用于目录时，由于文件不是目录而导致失败的检查异常。
NotLinkException	由于文件不是符号链接，文件系统操作失败时抛出的检查异常。
ProviderMismatchException	当尝试使用由不同文件系统提供程序创建的参数在一个文件系统提供程序创建的对象上调用方法时抛出未检查的异常。
ProviderNotFoundException	无法找到所需类型的提供者时抛出的运行时异常。
ReadOnlyFileSystemException	尝试更新与 read-only FileSystem的对象时抛出未检查的异常。

Package java.nio.file Description

Defines interfaces and classes for the Java virtual machine to access files, file attributes, and file systems.

The java.nio.file package defines classes to access files and file systems. The API to access file and file system attributes is defined in the java.nio.file.attribute package. The java.nio.file.spi package is used by service provider implementors wishing to extend the platform default provider, or to construct other provider implementations.

Symbolic Links

Many operating systems and file systems support for symbolic links. A symbolic link is a special file that serves as a reference to another file. For the most part, symbolic links are transparent to applications and operations on symbolic links are automatically redirected to the target of the link. Exceptions to this are when a symbolic link is deleted or renamed/moved in which case the link is deleted or removed rather than the target of the link. This package includes support for symbolic links where implementations provide these semantics. File systems may support other types that are semantically close but support for these other types of links is not included in this package.

Interoperability

The File class defines the toPath method to construct a Path by converting the abstract path represented by the java.io.File object. The resulting Path can be used to operate on the same file as the File object. The Path specification provides further information on the interoperability between Path and java.io.File objects.

Visibility

The view of the files and file system provided by classes in this package are guaranteed to be consistent with other views provided by other instances in the same Java virtual machine. The view may or may not, however, be consistent with the view of the file system as seen by other concurrently running programs due to caching performed by the underlying operating system and delays induced by network-filesystem protocols. This is true regardless of the language in which these other programs are written, and whether they are running on the same machine or on some other machine. The exact nature of any such inconsistencies are system-dependent and are therefore unspecified.

Synchronized I/O File Integrity

The SYNC and DSYNC options are used when opening a file to require that updates to the file are written synchronously to the underlying storage device. In the case of the default provider, and the file resides on a local storage device, and the seekable channel is connected to a file that was opened with one of these options, then an invocation of the write method is only guaranteed to return when all changes made to the file by that invocation have been written to the device. These options are useful for ensuring that critical information is not lost in the event of a system crash. If the file does not reside on a local device then no such guarantee is made. Whether this guarantee is possible with other provider implementations is provider specific.

General Exceptions

Unless otherwise noted, passing a null argument to a constructor or method of any class or interface in this package will cause a NullPointerException to be thrown. Additionally, invoking a method with a collection containing a null element will cause a NullPointerException, unless otherwise specified.

Unless otherwise noted, methods that attempt to access the file system will throw ClosedFileSystemException when invoked on objects associated with a FileSystem that has been closed. Additionally, any methods that attempt write access to a file system will throw ReadOnlyFileSystemException when invoked on an object associated with a FileSystem that only provides read-only access.

Unless otherwise noted, invoking a method of any class or interface in this package created by one provider with a parameter that is an object created by another provider, will throw ProviderMismatchException.

Optional Specific Exceptions

Most of the methods defined by classes in this package that access the file system specify that IOException be thrown when an I/O error occurs. In some cases, these methods define specific I/O exceptions for common cases. These exceptions, noted as optional specific exceptions, are thrown by the implementation where it can detect the specific error. Where the specific error cannot be detected then the more general IOException is thrown.

从以下版本开始：

1.7