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| Using the file system API |
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| <h3>Using the file system API</h3> |
| <p> |
| The <tt>org.eclipse.core.filesystem</tt> plug-in provides a generic API for |
| interacting with an arbitrary file system. This API is similar to <tt>java.io.File</tt>, |
| with a few key differences: |
| </p> |
| <ul> |
| <li>Plug-ins can install providers for different types of file systems.</li> |
| <li>All methods integrate support for reporting progress and responding to cancelation, |
| making it easier to integrate into a graphical user interface.</li> |
| <li>There is support for some additional functionality not available in <tt>java.io.File</tt>, |
| such as getting and setting file permissions.</li> |
| <li>There are more convenience methods, such as copy, move, and recursive deletion.</li> |
| </ul> |
| <p> |
| In the file system API, the path for any given file is represented as a hierarchical |
| <tt>java.net.URI</tt>. The URI scheme represents the kind of file system, |
| and the URI path component represents the location of the file within the file |
| system tree. Thus any given hierarchical URI represents a potential file or |
| directory in some arbitrary file system. |
| </p> |
| <p> |
| The API for working with files and file systems is found in the |
| <b><a href="../reference/api/org/eclipse/core/filesystem/package-summary.html">org.eclipse.core.filesystem</a></b>) |
| package. The central API type is |
| <b><a href="../reference/api/org/eclipse/core/filesystem/IFileStore.html">IFileStore</a></b> |
| Each instance of <tt>IFileStore</tt> represents |
| a single file in the file system. As with <tt>IResource</tt>, the existence of |
| an <tt>IFileStore</tt> instance does not mean that such a file exists on disk. You |
| can use an <tt>IFileStore</tt> instance to create, delete, copy, move, or open |
| streams on files. For a given <tt>URI</tt>, you can get your hands on an <tt>IFileStore</tt> |
| instance using the static method <tt>EFS.getStore(URI)</tt> |
| </p> |
| <p> |
| The <b><a href="../reference/api/org/eclipse/core/filesystem/IFileSystem.html">IFileSystem</a></b> |
| interface can be used to find out things about the file system as a whole. Each |
| <tt>IFileSystem</tt> instance represents a single URI scheme, such as "file:", |
| "ftp:", etc. You can use this type to ask questions such as what file attributes |
| are supported, or whether the file system is case-sensitive. You can also use |
| this type to obtain an <tt>IFileStore</tt> for a given <tt>URI</tt>. |
| </p> |
| <p> |
| Most methods on <tt>IFileStore</tt> have a flag parameter that allows |
| extra options to be supplied. The flag values can be found |
| in the <b><a href="../reference/api/org/eclipse/core/filesystem/EFS.html">EFS</a></b> |
| class. For example, to open an output stream for appending to a file, use: |
| </p> |
| <pre> |
| IFileStore store = ...//some file store |
| store.openOutputStream(EFS.APPEND, null); |
| </pre> |
| <p> |
| If you want the default behaviour for a method, use <b>EFS.NONE</b>. |
| </p> |
| <p> |
| The <b><a href="../reference/api/org/eclipse/core/filesystem/IFileInfo.html">IFileInfo</a></b> |
| interface represents the state of a file at a particular moment in time. In particular, |
| you can find out if the file exists, whether it is a directory, what its attributes are, |
| and so on. This information can be modified and then set back into the file. For |
| example, here is a snippet that sets the read only attribute on a directory: |
| </p> |
| <pre> |
| IFileStore store = ...//some file store |
| IFileInfo info = store.fetchInfo(); |
| if (info.exists() && info.isDirectory()) { |
| info.setAttribute(EFS.ATTRIBUTE_READ_ONLY, true); |
| store.putInfo(info, EFS.SET_ATTRIBUTES, null); |
| } |
| </pre> |
| <p> |
| This style of API allows you to obtain and change file information with |
| a single call to the file system. In the above example, there is only |
| one file system call to fetch the info, and then you can perform as many |
| operations as you want on the <tt>IFileInfo</tt> object without hitting |
| the disk again. |
| </p> |
| <p> |
| The <b><a href="../reference/api/org/eclipse/core/filesystem/EFS.html">EFS</a></b> |
| class has static factory methods for obtaining <tt>IFileStore</tt> and <tt>IFileSystem</tt> |
| instances, as well as various option constants and error codes. |
| </p> |
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