de.schlichtherle.truezip.file.TFileInputStream Maven / Gradle / Ivy
/*
* Copyright (C) 2005-2011 Schlichtherle IT Services
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a cp of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package de.schlichtherle.truezip.file;
import de.schlichtherle.truezip.io.FileBusyException;
import de.schlichtherle.truezip.io.DecoratingInputStream;
import de.schlichtherle.truezip.fs.FsInputOption;
import de.schlichtherle.truezip.socket.InputSocket;
import de.schlichtherle.truezip.util.BitField;
import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import net.jcip.annotations.Immutable;
/**
* A replacement for the class {@link FileInputStream} for reading plain old
* files or entries in an archive file.
* Note that applications cannot read archive files directly using
* this class - just their entries.
*
* To prevent exceptions to be thrown subsequently, applications should
* always close their streams using the following idiom:
*
{@code
* TFileInputStream in = new TFileInputStream(file);
* try {
* // Do I/O here...
* } finally {
* in.close(); // ALWAYS close the stream!
* }
* }
*
* Note that the {@link #close()} method may throw an {@link IOException}, too.
* Applications need to deal with this appropriately, for example by enclosing
* the entire block with another {@code try-catch}-block:
*
{@code
* try {
* TFileInputStream in = new TFileInputStream(file);
* try {
* // Do I/O here...
* } finally {
* in.close(); // ALWAYS close the stream!
* }
* } catch (IOException ex) {
* ex.printStackTrace();
* }
* }
*
* Applications cannot read from an entry in an archive file if an implicit
* {@link TFile#umount() unmount} is required but cannot get performed because
* another {@link TFileInputStream} or {@link TFileOutputStream} object hasn't
* been closed or garbage collected yet.
* A {@link FileNotFoundException} is thrown by the constructors of this class
* in this case.
*
* If you would like to use this class in order to cp files,
* please consider using one of the
* cp methods of the class {@link TFile}
* instead.
* These methods provide ease of use, enhanced features, superior performance
* and require less space in the temp file folder.
*
* @see TFile#cat(InputStream, OutputStream)
* @see TFileOutputStream
* @author Christian Schlichtherle
* @version $Id$
*/
@DefaultAnnotation(NonNull.class)
@Immutable
public final class TFileInputStream extends DecoratingInputStream {
private static final BitField
DEFAULT_OPTIONS = BitField.noneOf(FsInputOption.class);
/**
* Constructs a new input stream for reading plain old files or entries
* in an archive file.
* This constructor calls {@link TFile#TFile(String) new TFile(path)} for
* the given path.
*
* @param path the path of the plain old file or entry in an archive file
* to read.
* @throws FileBusyException If the path denotes an archive entry and the
* archive driver does not support to create an additional input
* stream for the archive file.
* @throws FileNotFoundException On any other I/O related issue.
*/
public TFileInputStream(String path)
throws FileNotFoundException {
super(newInputStream(new TFile(path)));
}
/**
* Constructs a new input stream for reading plain old files or entries
* in an archive file.
*
* @param file the plain old file or entry in an archive file to read.
* @throws FileBusyException If the path denotes an archive entry and the
* archive driver does not support to create an additional input
* stream for the archive file.
* @throws FileNotFoundException On any other I/O related issue.
*/
public TFileInputStream(File file)
throws FileNotFoundException {
super(newInputStream(file));
}
private static InputStream newInputStream(final File src)
throws FileNotFoundException {
final InputSocket input = TBIO.getInputSocket(src, DEFAULT_OPTIONS);
try {
return input.newInputStream();
} catch (FileNotFoundException ex) {
throw ex;
} catch (IOException ex) {
throw (FileNotFoundException) new FileNotFoundException(
src.toString()).initCause(ex);
}
}
}