java.nio.file.spi.FileSystemProvider#installedProviders ( )源码实例Demo

boolean isJarFileSystemAvailable() {
    boolean result = false;
    for (FileSystemProvider fsp: FileSystemProvider.installedProviders()) {
        String scheme = fsp.getScheme();
        System.err.println("Provider: " + scheme + " " + fsp);
        if (scheme.equalsIgnoreCase("jar") || scheme.equalsIgnoreCase("zip"))
            result = true;
    }
    return result;
}
 

public static BundleFileSystemProvider getInstance() {
	for (FileSystemProvider provider : FileSystemProvider
			.installedProviders()) {
		if (provider instanceof BundleFileSystemProvider) {
			return (BundleFileSystemProvider) provider;
		}
	}
	// Not installed!
	// Fallback for OSGi environments
	return Singleton.INSTANCE;
}
 

boolean isJarFileSystemAvailable() {
    boolean result = false;
    for (FileSystemProvider fsp: FileSystemProvider.installedProviders()) {
        String scheme = fsp.getScheme();
        System.err.println("Provider: " + scheme + " " + fsp);
        if (scheme.equalsIgnoreCase("jar") || scheme.equalsIgnoreCase("zip"))
            result = true;
    }
    return result;
}
 

boolean isJarFileSystemAvailable() {
    boolean result = false;
    for (FileSystemProvider fsp: FileSystemProvider.installedProviders()) {
        String scheme = fsp.getScheme();
        System.err.println("Provider: " + scheme + " " + fsp);
        if (scheme.equalsIgnoreCase("jar") || scheme.equalsIgnoreCase("zip"))
            result = true;
    }
    return result;
}
 

public synchronized FileSystemProvider getJarFSProvider() {
    if (jarFSProvider != null) {
        return jarFSProvider;
    }
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equals("jar")) {
            return (jarFSProvider = provider);
        }
    }
    return null;
}
 

@Nonnull
private static GitFileSystemProvider getInstalledProvider() {
  GitFileSystemProvider ret = null;
  for(FileSystemProvider provider : FileSystemProvider.installedProviders()) {
    if(provider instanceof GitFileSystemProvider) {
      ret = (GitFileSystemProvider) provider;
      break;
    }
  }
  if(ret == null)
    ret = new GitFileSystemProvider();
  return ret;
}
 

private static void listFilesystems() {
  System.out.println("Installed filesystem providers:");
  for (FileSystemProvider p : FileSystemProvider.installedProviders()) {
    System.out.println("  " + p.getScheme());
  }
}
 

public static void main(String[] args) throws Exception {
    Path zipfile = Paths.get(args[0]);

    // Test: zip should should be returned in provider list
    boolean found = false;

    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equalsIgnoreCase("jar")) {
            found = true;
            break;
        }
    }
    if (!found)
        throw new RuntimeException("'jar' provider not installed");

    // Test: FileSystems#newFileSystem(Path)
    Map<String,?> env = new HashMap<String,Object>();
    FileSystems.newFileSystem(zipfile, null).close();

    // Test: FileSystems#newFileSystem(URI)
    URI uri = new URI("jar", zipfile.toUri().toString(), null);
    FileSystem fs = FileSystems.newFileSystem(uri, env, null);

    // Test: exercise toUri method
    String expected = uri.toString() + "!/foo";
    String actual = fs.getPath("/foo").toUri().toString();
    if (!actual.equals(expected)) {
        throw new RuntimeException("toUri returned '" + actual +
            "', expected '" + expected + "'");
    }

    // Test: exercise directory iterator and retrieval of basic attributes
    Files.walkFileTree(fs.getPath("/"), new FileTreePrinter());

    // Test: DirectoryStream
    found = false;
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(fs.getPath("/"))) {
        for (Path entry: stream) {
            found = entry.toString().equals("/META-INF/");
            if (found) break;
        }
    }

    if (!found)
        throw new RuntimeException("Expected file not found");

    // Test: copy file from zip file to current (scratch) directory
    Path source = fs.getPath("/META-INF/services/java.nio.file.spi.FileSystemProvider");
    if (Files.exists(source)) {
        Path target = Paths.get(source.getFileName().toString());
        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
        try {
            long s1 = Files.readAttributes(source, BasicFileAttributes.class).size();
            long s2 = Files.readAttributes(target, BasicFileAttributes.class).size();
            if (s2 != s1)
                throw new RuntimeException("target size != source size");
        } finally {
            Files.delete(target);
        }
    }

    // Test: FileStore
    FileStore store = Files.getFileStore(fs.getPath("/"));
    if (!store.supportsFileAttributeView("basic"))
        throw new RuntimeException("BasicFileAttributeView should be supported");

    // Test: ClosedFileSystemException
    fs.close();
    if (fs.isOpen())
        throw new RuntimeException("FileSystem should be closed");
    try {
        fs.provider().checkAccess(fs.getPath("/missing"), AccessMode.READ);
    } catch (ClosedFileSystemException x) { }
}
 

public static void main(String[] args) throws Exception {
    Path zipfile = Paths.get(args[0]);

    // Test: zip should should be returned in provider list
    boolean found = false;

    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equalsIgnoreCase("jar")) {
            found = true;
            break;
        }
    }
    if (!found)
        throw new RuntimeException("'jar' provider not installed");

    // Test: FileSystems#newFileSystem(Path)
    Map<String,?> env = new HashMap<String,Object>();
    FileSystems.newFileSystem(zipfile, null).close();

    // Test: FileSystems#newFileSystem(URI)
    URI uri = new URI("jar", zipfile.toUri().toString(), null);
    FileSystem fs = FileSystems.newFileSystem(uri, env, null);

    // Test: exercise toUri method
    String expected = uri.toString() + "!/foo";
    String actual = fs.getPath("/foo").toUri().toString();
    if (!actual.equals(expected)) {
        throw new RuntimeException("toUri returned '" + actual +
            "', expected '" + expected + "'");
    }

    // Test: exercise directory iterator and retrieval of basic attributes
    Files.walkFileTree(fs.getPath("/"), new FileTreePrinter());

    // Test: DirectoryStream
    found = false;
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(fs.getPath("/"))) {
        for (Path entry: stream) {
            found = entry.toString().equals("/META-INF/");
            if (found) break;
        }
    }

    if (!found)
        throw new RuntimeException("Expected file not found");

    // Test: copy file from zip file to current (scratch) directory
    Path source = fs.getPath("/META-INF/services/java.nio.file.spi.FileSystemProvider");
    if (Files.exists(source)) {
        Path target = Paths.get(source.getFileName().toString());
        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
        try {
            long s1 = Files.readAttributes(source, BasicFileAttributes.class).size();
            long s2 = Files.readAttributes(target, BasicFileAttributes.class).size();
            if (s2 != s1)
                throw new RuntimeException("target size != source size");
        } finally {
            Files.delete(target);
        }
    }

    // Test: FileStore
    FileStore store = Files.getFileStore(fs.getPath("/"));
    if (!store.supportsFileAttributeView("basic"))
        throw new RuntimeException("BasicFileAttributeView should be supported");

    // Test: ClosedFileSystemException
    fs.close();
    if (fs.isOpen())
        throw new RuntimeException("FileSystem should be closed");
    try {
        fs.provider().checkAccess(fs.getPath("/missing"), AccessMode.READ);
    } catch (ClosedFileSystemException x) { }
}
 

public static void main(String[] args) throws Exception {
    Path zipfile = Paths.get(args[0]);

    // Test: zip should should be returned in provider list
    boolean found = false;

    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equalsIgnoreCase("jar")) {
            found = true;
            break;
        }
    }
    if (!found)
        throw new RuntimeException("'jar' provider not installed");

    // Test: FileSystems#newFileSystem(Path)
    Map<String,?> env = new HashMap<String,Object>();
    FileSystems.newFileSystem(zipfile, null).close();

    // Test: FileSystems#newFileSystem(URI)
    URI uri = new URI("jar", zipfile.toUri().toString(), null);
    FileSystem fs = FileSystems.newFileSystem(uri, env, null);

    // Test: exercise toUri method
    String expected = uri.toString() + "!/foo";
    String actual = fs.getPath("/foo").toUri().toString();
    if (!actual.equals(expected)) {
        throw new RuntimeException("toUri returned '" + actual +
            "', expected '" + expected + "'");
    }

    // Test: exercise directory iterator and retrieval of basic attributes
    Files.walkFileTree(fs.getPath("/"), new FileTreePrinter());

    // Test: DirectoryStream
    found = false;
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(fs.getPath("/"))) {
        for (Path entry: stream) {
            found = entry.toString().equals("/META-INF/");
            if (found) break;
        }
    }

    if (!found)
        throw new RuntimeException("Expected file not found");

    // Test: copy file from zip file to current (scratch) directory
    Path source = fs.getPath("/META-INF/services/java.nio.file.spi.FileSystemProvider");
    if (Files.exists(source)) {
        Path target = Paths.get(source.getFileName().toString());
        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
        try {
            long s1 = Files.readAttributes(source, BasicFileAttributes.class).size();
            long s2 = Files.readAttributes(target, BasicFileAttributes.class).size();
            if (s2 != s1)
                throw new RuntimeException("target size != source size");
        } finally {
            Files.delete(target);
        }
    }

    // Test: FileStore
    FileStore store = Files.getFileStore(fs.getPath("/"));
    if (!store.supportsFileAttributeView("basic"))
        throw new RuntimeException("BasicFileAttributeView should be supported");

    // Test: ClosedFileSystemException
    fs.close();
    if (fs.isOpen())
        throw new RuntimeException("FileSystem should be closed");
    try {
        fs.provider().checkAccess(fs.getPath("/missing"), AccessMode.READ);
    } catch (ClosedFileSystemException x) { }
}
 

public static void main(String[] args) throws Exception {
    Path zipfile = Paths.get(args[0]);

    // Test: zip should should be returned in provider list
    boolean found = false;

    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equalsIgnoreCase("jar")) {
            found = true;
            break;
        }
    }
    if (!found)
        throw new RuntimeException("'jar' provider not installed");

    // Test: FileSystems#newFileSystem(Path)
    Map<String,?> env = new HashMap<String,Object>();
    FileSystems.newFileSystem(zipfile, null).close();

    // Test: FileSystems#newFileSystem(URI)
    URI uri = new URI("jar", zipfile.toUri().toString(), null);
    FileSystem fs = FileSystems.newFileSystem(uri, env, null);

    // Test: exercise toUri method
    String expected = uri.toString() + "!/foo";
    String actual = fs.getPath("/foo").toUri().toString();
    if (!actual.equals(expected)) {
        throw new RuntimeException("toUri returned '" + actual +
            "', expected '" + expected + "'");
    }

    // Test: exercise directory iterator and retrieval of basic attributes
    Files.walkFileTree(fs.getPath("/"), new FileTreePrinter());

    // Test: DirectoryStream
    found = false;
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(fs.getPath("/"))) {
        for (Path entry: stream) {
            found = entry.toString().equals("/META-INF/");
            if (found) break;
        }
    }

    if (!found)
        throw new RuntimeException("Expected file not found");

    // Test: copy file from zip file to current (scratch) directory
    Path source = fs.getPath("/META-INF/services/java.nio.file.spi.FileSystemProvider");
    if (Files.exists(source)) {
        Path target = Paths.get(source.getFileName().toString());
        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
        try {
            long s1 = Files.readAttributes(source, BasicFileAttributes.class).size();
            long s2 = Files.readAttributes(target, BasicFileAttributes.class).size();
            if (s2 != s1)
                throw new RuntimeException("target size != source size");
        } finally {
            Files.delete(target);
        }
    }

    // Test: FileStore
    FileStore store = Files.getFileStore(fs.getPath("/"));
    if (!store.supportsFileAttributeView("basic"))
        throw new RuntimeException("BasicFileAttributeView should be supported");

    // Test: ClosedFileSystemException
    fs.close();
    if (fs.isOpen())
        throw new RuntimeException("FileSystem should be closed");
    try {
        fs.provider().checkAccess(fs.getPath("/missing"), AccessMode.READ);
    } catch (ClosedFileSystemException x) { }
}
 

public void testFileSystemIsRegistered() throws URISyntaxException {

		// Check that the expected "memory0" FileSystem is available
		boolean foundInitialProvider = false;

		for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
			if (provider.getScheme().equalsIgnoreCase("memory0")) {
				foundInitialProvider = true;
			}
		}

		assertTrue("Unable to find intial provider 'memory0'", foundInitialProvider);


		FileSystem memoryFileSystem = FileSystems.getFileSystem(new URI("memory0:///"));
		assertNotNull("Returned memoryFileSystem for 'memory0:///' was null", memoryFileSystem);

		String filename = "bargh";
		assertNotNull("Returned filename for 'memory0:///"+filename+"' was null", memoryFileSystem.getPath(filename));
		
		assertEquals("MemoryFileSystem did not return the expected string representation",
				"/memory/" + filename, memoryFileSystem.getPath(filename).toString());


	}
 

public static void main(String[] args) throws Exception {
    Path zipfile = Paths.get(args[0]);

    // Test: zip should should be returned in provider list
    boolean found = false;

    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (provider.getScheme().equalsIgnoreCase("jar")) {
            found = true;
            break;
        }
    }
    if (!found)
        throw new RuntimeException("'jar' provider not installed");

    // Test: FileSystems#newFileSystem(Path)
    Map<String,?> env = new HashMap<String,Object>();
    FileSystems.newFileSystem(zipfile, null).close();

    // Test: FileSystems#newFileSystem(URI)
    URI uri = new URI("jar", zipfile.toUri().toString(), null);
    FileSystem fs = FileSystems.newFileSystem(uri, env, null);

    // Test: exercise toUri method
    String expected = uri.toString() + "!/foo";
    String actual = fs.getPath("/foo").toUri().toString();
    if (!actual.equals(expected)) {
        throw new RuntimeException("toUri returned '" + actual +
            "', expected '" + expected + "'");
    }

    // Test: exercise directory iterator and retrieval of basic attributes
    Files.walkFileTree(fs.getPath("/"), new FileTreePrinter());

    // Test: DirectoryStream
    found = false;
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(fs.getPath("/"))) {
        for (Path entry: stream) {
            found = entry.toString().equals("/META-INF/");
            if (found) break;
        }
    }

    if (!found)
        throw new RuntimeException("Expected file not found");

    // Test: copy file from zip file to current (scratch) directory
    Path source = fs.getPath("/META-INF/services/java.nio.file.spi.FileSystemProvider");
    if (Files.exists(source)) {
        Path target = Paths.get(source.getFileName().toString());
        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
        try {
            long s1 = Files.readAttributes(source, BasicFileAttributes.class).size();
            long s2 = Files.readAttributes(target, BasicFileAttributes.class).size();
            if (s2 != s1)
                throw new RuntimeException("target size != source size");
        } finally {
            Files.delete(target);
        }
    }

    // Test: FileStore
    FileStore store = Files.getFileStore(fs.getPath("/"));
    if (!store.supportsFileAttributeView("basic"))
        throw new RuntimeException("BasicFileAttributeView should be supported");

    // Test: ClosedFileSystemException
    fs.close();
    if (fs.isOpen())
        throw new RuntimeException("FileSystem should be closed");
    try {
        fs.provider().checkAccess(fs.getPath("/missing"), AccessMode.READ);
    } catch (ClosedFileSystemException x) { }
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}
 

/**
 * Returns a reference to an existing {@code FileSystem}.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers to locate the provider that is identified by the URI
 * {@link URI#getScheme scheme} of the given URI. URI schemes are compared
 * without regard to case. The exact form of the URI is highly provider
 * dependent. If found, the provider's {@link FileSystemProvider#getFileSystem
 * getFileSystem} method is invoked to obtain a reference to the {@code
 * FileSystem}.
 *
 * <p> Once a file system created by this provider is {@link FileSystem#close
 * closed} it is provider-dependent if this method returns a reference to
 * the closed file system or throws {@link FileSystemNotFoundException}.
 * If the provider allows a new file system to be created with the same URI
 * as a file system it previously created then this method throws the
 * exception if invoked after the file system is closed (and before a new
 * instance is created by the {@link #newFileSystem newFileSystem} method).
 *
 * <p> If a security manager is installed then a provider implementation
 * may require to check a permission before returning a reference to an
 * existing file system. In the case of the {@link FileSystems#getDefault
 * default} file system, no permission check is required.
 *
 * @param   uri  the URI to locate the file system
 *
 * @return  the reference to the file system
 *
 * @throws  IllegalArgumentException
 *          if the pre-conditions for the {@code uri} parameter are not met
 * @throws  FileSystemNotFoundException
 *          if the file system, identified by the URI, does not exist
 * @throws  ProviderNotFoundException
 *          if a provider supporting the URI scheme is not installed
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 */
public static FileSystem getFileSystem(URI uri) {
    String scheme = uri.getScheme();
    for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {
        if (scheme.equalsIgnoreCase(provider.getScheme())) {
            return provider.getFileSystem(uri);
        }
    }
    throw new ProviderNotFoundException("Provider \"" + scheme + "\" not found");
}