程序包 java.nio.file.spi

类 FileTypeDetector

java.lang.Object

java.nio.file.spi.FileTypeDetector

public abstract class FileTypeDetector
extends Object

A file type detector for probing a file to guess its file type.

A file type detector is a concrete implementation of this class, has a zero-argument constructor, and implements the abstract methods specified below.

The means by which a file type detector determines the file type is highly implementation specific. A simple implementation might examine the file extension (a convention used in some platforms) and map it to a file type. In other cases, the file type may be stored as a file attribute or the bytes in a file may be examined to guess its file type.

从以下版本开始:

1.7

另请参阅:

Files.probeContentType(Path)

构造器概要

构造器

限定符	构造器	说明
protected	FileTypeDetector()	Initializes a new instance of this class.

方法概要

限定符和类型	方法	说明
abstract String	probeContentType(Path path)	Probes the given file to guess its content type.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

FileTypeDetector

protected FileTypeDetector()

Initializes a new instance of this class.

抛出:

SecurityException - If a security manager has been installed and it denies RuntimePermission("fileTypeDetector")

方法详细资料

probeContentType

public abstract String probeContentType(Path path)
                                 throws IOException

Probes the given file to guess its content type.

The means by which this method determines the file type is highly implementation specific. It may simply examine the file name, it may use a file attribute, or it may examines bytes in the file.

The probe result is the string form of the value of a Multipurpose Internet Mail Extension (MIME) content type as defined by RFC 2045: Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies. The string must be parsable according to the grammar in the RFC 2045.

参数:

path - the path to the file to probe

返回:

The content type or null if the file type is not recognized

抛出:

IOException - An I/O error occurs

SecurityException - If the implementation requires to access the file, and a security manager is installed, and it denies an unspecified permission required by a file system provider implementation. If the file reference is associated with the default file system provider then the SecurityManager#checkRead(String) method is invoked to check read access to the file.

另请参阅:

Files.probeContentType(java.nio.file.Path)