接口 Resource

方法详细资料

• exists

  boolean exists()

  Determine whether this resource actually exists in physical form.

  This method performs a definitive existence check, whereas the existence of a Resource handle only guarantees a valid descriptor handle.

• isReadable

  default boolean isReadable()

  Indicate whether non-empty contents of this resource can be read via InputStreamSource.getInputStream().

  Will be true for typical resource descriptors that exist since it strictly implies exists() semantics as of 5.1. Note that actual content reading may still fail when attempted. However, a value of false is a definitive indication that the resource content cannot be read.

  另请参阅:

  InputStreamSource.getInputStream(), exists()

• isOpen

  default boolean isOpen()

  Indicate whether this resource represents a handle with an open stream. If true, the InputStream cannot be read multiple times, and must be read and closed to avoid resource leaks.

  Will be false for typical resource descriptors.

• isFile

  default boolean isFile()

  Determine whether this resource represents a file in a file system. A value of true strongly suggests (but does not guarantee) that a getFile() call will succeed.

  This is conservatively false by default.

  从以下版本开始:

  5.0

  另请参阅:

  getFile()

• getURL

  URL getURL()
      throws IOException

  Return a URL handle for this resource.

  抛出:

  IOException - if the resource cannot be resolved as URL, i.e. if the resource is not available as descriptor

• getURI

  URI getURI()
      throws IOException

  Return a URI handle for this resource.

  抛出:

  IOException - if the resource cannot be resolved as URI, i.e. if the resource is not available as descriptor

  从以下版本开始:

  2.5

• getFile

  File getFile()
        throws IOException

  Return a File handle for this resource.

  抛出:

  FileNotFoundException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system

  IOException - in case of general resolution/reading failures

  另请参阅:

  InputStreamSource.getInputStream()

• readableChannel

  default ReadableByteChannel readableChannel()
                                       throws IOException

  Return a ReadableByteChannel.

  It is expected that each call creates a fresh channel.

  The default implementation returns Channels.newChannel(InputStream) with the result of InputStreamSource.getInputStream().

  返回:

  the byte channel for the underlying resource (must not be null)

  抛出:

  FileNotFoundException - if the underlying resource doesn't exist

  IOException - if the content channel could not be opened

  从以下版本开始:

  5.0

  另请参阅:

  InputStreamSource.getInputStream()

• contentLength

  long contentLength()
              throws IOException

  Determine the content length for this resource.

  抛出:

  IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)

• lastModified

  long lastModified()
             throws IOException

  Determine the last-modified timestamp for this resource.

  抛出:

  IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)

• createRelative

  Resource createRelative​(String relativePath)
                   throws IOException

  Create a resource relative to this resource.

  参数:

  relativePath - the relative path (relative to this resource)

  返回:

  the resource handle for the relative resource

  抛出:

  IOException - if the relative resource cannot be determined

• getFilename

  @Nullable
  String getFilename()

  Determine a filename for this resource, i.e. typically the last part of the path: for example, "myfile.txt".

  Returns null if this type of resource does not have a filename.

• getDescription

  String getDescription()

  Return a description for this resource, to be used for error output when working with the resource.

  Implementations are also encouraged to return this value from their toString method.

  另请参阅:

  Object.toString()