Package net.automatalib.common.util

Class IOUtil

java.lang.Object

net.automatalib.common.util.IOUtil

public final class IOUtil
extends Object

Utility methods for operating with java.io.* classes.

Method Summary

Modifier and Type	Method	Description
static InputStream	asBufferedInputStream(File file)	Returns an input stream that reads the contents of the given file.
static InputStream	asBufferedInputStream(InputStream is)	Ensures that the returned stream is a buffered version of the supplied input stream.
static OutputStream	asBufferedNonClosingOutputStream(OutputStream os)	Returns a buffered output stream that does not propagate calls to OutputStream.close() to the passed os.
static Writer	asBufferedNonClosingUTF8Writer(OutputStream os)	Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding and does not propagate calls to Writer.close() to the passed os.
static OutputStream	asBufferedOutputStream(File file)	Returns an output stream that writes the contents to the given file.
static OutputStream	asBufferedOutputStream(OutputStream os)	Ensures that the returned stream is a buffered version of the supplied output stream.
static Reader	asBufferedUTF8Reader(File file)	Returns a reader that parses the contents of the given file with StandardCharsets.UTF_8 encoding.
static Reader	asBufferedUTF8Reader(InputStream is)	Returns a reader that parses the contents of the given input stream with StandardCharsets.UTF_8 encoding.
static Writer	asBufferedUTF8Writer(File file)	Returns a writer that writes contents to the given file with StandardCharsets.UTF_8 encoding.
static Writer	asBufferedUTF8Writer(OutputStream os)	Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding.
static InputStream	asUncompressedBufferedNonClosingInputStream(InputStream is)	Returns a buffered input stream that de-compresses the contents of is (in case the given input stream contains gzip'ed content) and does not propagate calls to InputStream.close() to the passed is.
static Reader	asUncompressedBufferedNonClosingUTF8Reader(InputStream is)	Returns a buffered reader that un-compresses the contents of is (in case the given input stream contains gzip'ed content), does not propagate calls to Reader.close() to the passed is and parses the contents of the given input stream with StandardCharsets.UTF_8 encoding.
static InputStream	asUncompressedInputStream(InputStream is)	Ensures that the returned stream is an uncompressed version of the supplied input stream.
static Reader	asUTF8Reader(InputStream is)	Returns a reader that parses the contents of the given input stream with StandardCharsets.UTF_8 encoding.
static Writer	asUTF8Writer(OutputStream os)	Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

asUncompressedInputStream

public static InputStream asUncompressedInputStream(InputStream is)
                                             throws IOException

Ensures that the returned stream is an uncompressed version of the supplied input stream.

This method first tries to read the first two bytes from the stream, then resets the stream. If the first two bytes equal the GZip magic number (see GZIPInputStream.GZIP_MAGIC), the supplied stream is wrapped in a GZIPInputStream. Otherwise, the stream is returned as-is.

Note: this requires the input stream to support marking.

Parameters:

is - the input stream

Returns:

an uncompressed version of is

Throws:

IOException - if reading the magic number fails

IllegalArgumentException - if the stream does not support marking

asBufferedInputStream

public static InputStream asBufferedInputStream(InputStream is)

Ensures that the returned stream is a buffered version of the supplied input stream. The result must not necessarily be an instance of BufferedInputStream, it can also be, e.g., a ByteArrayInputStream, depending on the type of the supplied input stream.

Parameters:

is - the input stream

Returns:

a buffered version of is

asBufferedInputStream

public static InputStream asBufferedInputStream(File file)
                                         throws IOException

Returns an input stream that reads the contents of the given file. Additionally, buffers the input stream to improve performance.

Parameters:

file - the file to read

Returns:

a buffered input stream for the file contents

Throws:

IOException - if accessing the file results in an I/O error

asBufferedOutputStream

public static OutputStream asBufferedOutputStream(OutputStream os)

Ensures that the returned stream is a buffered version of the supplied output stream. The result must not necessarily be an instance of BufferedOutputStream, it can also be, e.g., a ByteArrayOutputStream, depending on the type of the supplied output stream.

Parameters:

os - the output stream

Returns:

a buffered version of os

asBufferedOutputStream

public static OutputStream asBufferedOutputStream(File file)
                                           throws IOException

Returns an output stream that writes the contents to the given file. Additionally, buffers the input stream to improve performance.

Parameters:

file - the file to write to

Returns:

a buffered output stream for the file contents

Throws:

IOException - if accessing the file results in an I/O error

asBufferedUTF8Reader

public static Reader asBufferedUTF8Reader(File file)
                                   throws IOException

Returns a reader that parses the contents of the given file with StandardCharsets.UTF_8 encoding. Additionally, buffers the input stream to improve performance.

Parameters:

file - the file to read

Returns:

a buffered, UTF-8-decoding reader for the file contents

Throws:

IOException - if accessing the file results in an I/O error

asBufferedUTF8Reader

public static Reader asBufferedUTF8Reader(InputStream is)

Returns a reader that parses the contents of the given input stream with StandardCharsets.UTF_8 encoding. If the given input stream is not already a buffering input stream, additionally buffers the input stream to improve performance.

Implementation note: the input stream (byte-wise representation) will be buffered, not the reader (character-wise representation).

Parameters:

is - the input stream to read

Returns:

a buffered, UTF-8-decoding reader for the input stream.

asUTF8Reader

public static Reader asUTF8Reader(InputStream is)

Returns a reader that parses the contents of the given input stream with StandardCharsets.UTF_8 encoding.

Parameters:

is - the input stream to read

Returns:

a UTF-8-decoding reader for the input stream

asBufferedUTF8Writer

public static Writer asBufferedUTF8Writer(File file)
                                   throws IOException

Returns a writer that writes contents to the given file with StandardCharsets.UTF_8 encoding. Additionally, buffers the input stream to improve performance.

Parameters:

file - the file to write to

Returns:

a buffered, UTF-8-encoding writer for the file contents

Throws:

IOException - if writing to the file results in I/O errors

asBufferedUTF8Writer

public static Writer asBufferedUTF8Writer(OutputStream os)

Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding. If the given output stream is not already a buffering output stream, additionally buffers the output stream to improve performance.

Implementation note: the output stream (byte-wise representation) will be buffered, not the writer (character- wise representation).

Parameters:

os - the output stream to write to

Returns:

a buffered, UTF-8 encoding writer for the output stream

asUTF8Writer

public static Writer asUTF8Writer(OutputStream os)

Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding.

Parameters:

os - the output stream to write to

Returns:

a UTF-8-encoding writer for the output stream.

asUncompressedBufferedNonClosingInputStream

public static InputStream asUncompressedBufferedNonClosingInputStream(InputStream is)
                                                               throws IOException

Returns a buffered input stream that de-compresses the contents of is (in case the given input stream contains gzip'ed content) and does not propagate calls to InputStream.close() to the passed is.

Parameters:

is - the input stream to read

Returns:

a (potentially) de-compressing, buffered, non-closing version of is

Throws:

IOException - if reading the stream (for detecting whether it contains compressed contents) fails

See Also:

NonClosingInputStream, asBufferedInputStream(InputStream), asUncompressedInputStream(InputStream)

asUncompressedBufferedNonClosingUTF8Reader

public static Reader asUncompressedBufferedNonClosingUTF8Reader(InputStream is)
                                                         throws IOException

Returns a buffered reader that un-compresses the contents of is (in case the given input stream contains gzip'ed content), does not propagate calls to Reader.close() to the passed is and parses the contents of the given input stream with StandardCharsets.UTF_8 encoding.

Implementation note: the input stream (byte-wise representation) will be buffered, not the reader (character-wise representation).

Parameters:

is - the input stream to read

Returns:

a (potentially) de-compressing, buffered, non-closing, UTF-8-decoding version of is

Throws:

IOException - if reading the stream (for detecting whether it contains compressed contents) fails

See Also:

asUTF8Reader(InputStream), asUncompressedBufferedNonClosingInputStream(InputStream)

asBufferedNonClosingOutputStream

public static OutputStream asBufferedNonClosingOutputStream(OutputStream os)

Returns a buffered output stream that does not propagate calls to OutputStream.close() to the passed os.

Parameters:

os - the output stream to write to

Returns:

a buffered, non-closing version of os

See Also:

asBufferedOutputStream(OutputStream), NonClosingOutputStream

asBufferedNonClosingUTF8Writer

public static Writer asBufferedNonClosingUTF8Writer(OutputStream os)

Returns a writer that writes contents to the given output stream with StandardCharsets.UTF_8 encoding and does not propagate calls to Writer.close() to the passed os.

Implementation note: the output stream (byte-wise representation) will be buffered, not the writer (character- wise representation).

Parameters:

os - the output stream to write to

Returns:

a buffered, non-closing, UTF-8-encoding writer for the output stream

See Also:

asBufferedNonClosingOutputStream(OutputStream), asUTF8Writer(OutputStream)