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| Working with resources in other file systems |
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| <h3>Working with resources in other file systems</h3> |
| |
| <p> |
| Most of the API in the <b><a href="../reference/api/org/eclipse/core/resources/IResource.html">IResource</a></b> |
| hierarchy works the same way |
| regardless of what kind of file system the resources are stored in. However, |
| there are some particular APIs that you need to avoid when working with |
| resources in other file systems, because they are only designed to work |
| with the local file system. |
| </p> |
| <p> |
| In particular, the <b><a href="../reference/api/org/eclipse/core/resources/IResource.html">IResource</a>.getLocation</b> method is specified to return |
| the local file system path of the resource. If the resource is in some other file |
| system, then this method is not applicable and will return <tt>null</tt>. |
| It is better to use the method <b>getLocationURI</b> instead, |
| which works regardless of what kind of file system the resource is stored in. |
| </p> |
| <p> |
| Similarly, the method |
| <b><a href="../reference/api/org/eclipse/core/resources/IProjectDescription.html">IProjectDescription</a> getLocation</b> |
| and <b>setLocation</b> methods should be avoided because they are |
| only effective in the local file system. The URI-based location methods should |
| be used instead. |
| </p> |
| <h4>Local caching</h4> |
| <p> |
| Say you are working with resources that are not in the local file system, but you |
| really need a local file. For example, you may be using a library that has a |
| dependency on <tt>java.io.File</tt>). In this case you can use the |
| <tt>IFileStore.toLocalFile</tt> method to obtain a local copy of the file. Note that |
| this will only cause one file or directory to be cached locally, rather than an entire |
| directory tree. Here is an example of using local caching to open a zip file on |
| an IFileStore: |
| </p> |
| <pre> |
| IFileStore store = ...;//some file store |
| java.io.File file = store.toLocalFile(EFS.NONE, null); |
| if (file == null) { |
| //we are not a local file store, so we need to cache a local copy |
| file = store.toLocalFile(EFS.CACHE, null); |
| } |
| java.util.zip.ZipFile zip = new java.util.ZipFile(file); |
| </pre> |
| <h4>Linking to other file systems</h4> |
| <p> |
| You can use linked resources to create projects that draw together resources |
| from multiple file systems. Simply use the method |
| <b><a href="../reference/api/org/eclipse/core/resources/IFile.html">IFile</a>.createLink(URI, int, IProgressMonitor)</b> or |
| <b><a href="../reference/api/org/eclipse/core/resources/IFolder.html">IFolder</a>.createLink(URI, int, IProgressMonitor)</b> |
| to create a resource in an existing project whose contents are stored in another location in |
| an arbitrary file system. You can even create links below other linked resources to |
| create arbitrary resource trees drawing from many different file systems. Here |
| is a simple example that creates a sibling linked file that shares the same file |
| system location as the source: |
| </p> |
| <pre> |
| IFile source = ...;//some source file |
| IFile link = source.getParent().getFile(new Path(source.getName() + ".link")); |
| link.createLink(source.getLocationURI(), IResource.NONE, null); |
| </pre> |
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