IFileVisitor Interface

Reference

Definition

Namespace:: Java.Nio.FileNio

Assembly:: Mono.Android.dll

Important

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A visitor of files.

[Android.Runtime.Register("java/nio/file/FileVisitor", "", "Java.Nio.FileNio.IFileVisitorInvoker", ApiSince=26)]
[Java.Interop.JavaTypeParameters(new System.String[] { "T" })]
public interface IFileVisitor : Android.Runtime.IJavaObject, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("java/nio/file/FileVisitor", "", "Java.Nio.FileNio.IFileVisitorInvoker", ApiSince=26)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "T" })>]
type IFileVisitor = interface
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Derived: Java.Nio.FileNio.SimpleFileVisitor

Attributes: RegisterAttribute JavaTypeParametersAttribute

Implements: IJavaObject IJavaPeerable IDisposable

Remarks

A visitor of files. An implementation of this interface is provided to the Files#walkFileTree Files.walkFileTree methods to visit each file in a file tree.

<b>Usage Examples:</b> Suppose we want to delete a file tree. In that case, each directory should be deleted after the entries in the directory are deleted.

Path start = ...
                Files.walkFileTree(start, new SimpleFileVisitor&lt;Path&gt;() {
                    &#64;Override
                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                        throws IOException
                    {
                        Files.delete(file);
                        return FileVisitResult.CONTINUE;
                    }
                    &#64;Override
                    public FileVisitResult postVisitDirectory(Path dir, IOException e)
                        throws IOException
                    {
                        if (e == null) {
                            Files.delete(dir);
                            return FileVisitResult.CONTINUE;
                        } else {
                            // directory iteration failed
                            throw e;
                        }
                    }
                });

Furthermore, suppose we want to copy a file tree to a target location. In that case, symbolic links should be followed and the target directory should be created before the entries in the directory are copied.

final Path source = ...
                final Path target = ...

                Files.walkFileTree(source, EnumSet.of(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE,
                    new SimpleFileVisitor&lt;Path&gt;() {
                        &#64;Override
                        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs)
                            throws IOException
                        {
                            Path targetdir = target.resolve(source.relativize(dir));
                            try {
                                Files.copy(dir, targetdir);
                            } catch (FileAlreadyExistsException e) {
                                 if (!Files.isDirectory(targetdir))
                                     throw e;
                            }
                            return CONTINUE;
                        }
                        &#64;Override
                        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                            throws IOException
                        {
                            Files.copy(file, target.resolve(source.relativize(file)));
                            return CONTINUE;
                        }
                    });

Added in 1.7.

Java documentation for java.nio.file.FileVisitor.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Properties

Handle	Gets the JNI value of the underlying Android object. (Inherited from IJavaObject)
JniIdentityHashCode	Returns the value of `java.lang.System.identityHashCode()` for the wrapped instance. (Inherited from IJavaPeerable)
JniManagedPeerState	State of the managed peer. (Inherited from IJavaPeerable)
JniPeerMembers	Member access and invocation support. (Inherited from IJavaPeerable)
PeerReference	Returns a JniObjectReference of the wrapped Java object instance. (Inherited from IJavaPeerable)

Methods

Disposed()	Called when the instance has been disposed. (Inherited from IJavaPeerable)
DisposeUnlessReferenced()	If there are no outstanding references to this instance, then calls `Dispose()`; otherwise, does nothing. (Inherited from IJavaPeerable)
Finalized()	Called when the instance has been finalized. (Inherited from IJavaPeerable)
PostVisitDirectory(Object, IOException)	Invoked for a directory after entries in the directory, and all of their descendants, have been visited.
PreVisitDirectory(Object, IBasicFileAttributes)	Invoked for a directory before entries in the directory are visited.
SetJniIdentityHashCode(Int32)	Set the value returned by `JniIdentityHashCode`. (Inherited from IJavaPeerable)
SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from IJavaPeerable)
SetPeerReference(JniObjectReference)	Set the value returned by `PeerReference`. (Inherited from IJavaPeerable)
UnregisterFromRuntime()	Unregister this instance so that the runtime will not return it from future Java.Interop.JniRuntime+JniValueManager.PeekValue invocations. (Inherited from IJavaPeerable)
VisitFile(Object, IBasicFileAttributes)	Invoked for a file in a directory.
VisitFileFailed(Object, IOException)	Invoked for a file that could not be visited.

Extension Methods

JavaCast<TResult>(IJavaObject)	Performs an Android runtime-checked type conversion.
JavaCast<TResult>(IJavaObject)
GetJniTypeName(IJavaPeerable)

Applies to

Dela via