Package gov.usgs.util

Class StreamUtils

java.lang.Object

gov.usgs.util.StreamUtils

public class StreamUtils
extends Object

Stream input, output, and transfer utilities.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StreamUtils.UnclosableInputStream	An InputStream that ignores calls to close.
static class	StreamUtils.UnclosableOutputStream	An OutputStream that ignores calls to close.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_BUFFER_SIZE	Default buffer size used for stream reads and writes.
static final int	DEFAULT_URL_CONNECT_TIMEOUT	Default connect timeout for url connections.
static final int	DEFAULT_URL_READ_TIMEOUT	Default read timeout for url connections.

Constructor Summary

Constructors

Constructor	Description
StreamUtils()

Method Summary

Modifier and Type	Method	Description
static void	closeStream(Object stream)	Close an InputStream or OutputStream.
static InputStream	getInputStream(Object obj)	Get an input stream for an Object if possible.
static OutputStream	getOutputStream(Object obj)	Same as calling getOutputStream(obj, false).
static OutputStream	getOutputStream(Object obj, boolean append)	Turn an object into an OutputStream if possible.
static InputStream	getURLInputStream(URL url)	Get an InputStream from a URL.
static InputStream	getURLInputStream(URL url, int connectTimeout, int readTimeout)	Get an InputStream from a URL.
static byte[]	readStream(Object from)	Read stream contents into a byte array.
static void	transferStream(Object from, Object to)	Transfer contents of Object from to Object to.
static void	transferStream(Object from, Object to, int bufferSize)	Transfer contents of Object from to Object to.

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE

Default buffer size used for stream reads and writes.

See Also:

• Constant Field Values

DEFAULT_URL_CONNECT_TIMEOUT

public static final int DEFAULT_URL_CONNECT_TIMEOUT

Default connect timeout for url connections.

See Also:

• Constant Field Values

DEFAULT_URL_READ_TIMEOUT

public static final int DEFAULT_URL_READ_TIMEOUT

Default read timeout for url connections.

See Also:

• Constant Field Values

Constructor Details

StreamUtils

public StreamUtils()

Method Details

getInputStream

public static InputStream getInputStream(Object obj)
                                  throws IOException,
IllegalArgumentException

Get an input stream for an Object if possible.

Parameters:

obj - an InputStream, File, byte[], or String.

Returns:

an InputStream or null. If obj is a File, the stream is Buffered.

Throws:

IOException - if an error occurs.

IllegalArgumentException - if obj is not an InputStream, URL, File, byte[], or String.

getURLInputStream

public static InputStream getURLInputStream(URL url)
                                     throws IOException

Get an InputStream from a URL. If URL is a HTTP url, attempts gzip compression.

Parameters:

url - the url being accessed.

Returns:

an InputStream to content at URL.

Throws:

IOException - if an error occurs.

getURLInputStream

public static InputStream getURLInputStream(URL url,
 int connectTimeout,
 int readTimeout)
                                     throws IOException

Get an InputStream from a URL. If URL is a HTTP url, attempts gzip compression.

Parameters:

url - the url being accessed.

connectTimeout - allowed time in milliseconds before connection.

readTimeout - allowed time in milliseconds before read.

Returns:

an InputStream to content at URL.

Throws:

IOException - if an error occurs.

getOutputStream

public static OutputStream getOutputStream(Object obj,
 boolean append)
                                    throws IOException

Turn an object into an OutputStream if possible.

Parameters:

obj - an OutputStream or File.

append - if obj is a file and this parameter is true, the output stream will be opened in append mode.

Returns:

an OutputStream. If obj is a File, the stream is Buffered.

Throws:

IOException - if an error occurs

getOutputStream

public static OutputStream getOutputStream(Object obj)
                                    throws IOException

Same as calling getOutputStream(obj, false). If obj is a file, it will open a new output stream and will not append.

Parameters:

obj - an OutputStream or File.

Returns:

an OutputStream. If obj is a File, the stream is Buffered.

Throws:

IOException - if an error occurs.

readStream

public static byte[] readStream(Object from)
                         throws IOException

Read stream contents into a byte array.

Parameters:

from - stream to read.

Returns:

byte array of file content.

Throws:

IOException - if an error occurs while reading.

transferStream

public static void transferStream(Object from,
 Object to)
                           throws IOException

Transfer contents of Object from to Object to. Calls transferStream(from, to, DEFAULT_BUFFER_SIZE).

Parameters:

from - streamable source.

to - streamable target.

Throws:

IOException - if IO error occurs

transferStream

public static void transferStream(Object from,
 Object to,
 int bufferSize)
                           throws IOException

Transfer contents of Object from to Object to. Uses getInputStream and getOutputStream to generate streams. Streams are closed after reading.

Parameters:

from - streamable source.

to - streamable target.

bufferSize - size of buffer

Throws:

IOException - if thrown by calls to read/write on streams.

closeStream

public static void closeStream(Object stream)

Close an InputStream or OutputStream.

Parameters:

stream - stream to close.