org.rhq.core.util.stream
Class StreamUtil

java.lang.Object
  org.rhq.core.util.stream.StreamUtil

public class StreamUtil
extends Object

Provides some utilities to work on streams and some (de)serialization methods..

Author:

John Mazzitelli

Method Summary

static long	copy(InputStream input, OutputStream output) Copies data from the input stream to the output stream.
static long	copy(InputStream input, OutputStream output, boolean closeStreams) Copies data from the input stream to the output stream.
static long	copy(InputStream input, OutputStream output, long startByte, long length) Copies data from the input stream to the output stream.
static long	copy(Reader rdr, Writer wrt) Equivalent of copy(InputStream, OutputStream) but using reader and writer instead of streams.
static long	copy(Reader rdr, Writer wrt, boolean closeStreams) Equivalent of copy(InputStream, OutputStream, boolean) only using reader and writer instead of input stream and output stream.
static Object	deserialize(byte[] serializedData) Deserializes the given serialization data and returns the object.
static void	safeClose(Closeable stream) Can be used to safely close a stream.
static byte[]	serialize(Serializable object) Given a serializable object, this will return the object's serialized byte array representation.
static byte[]	slurp(InputStream stream) Reads in the entire contents of the given input stream and returns the data in a byte array.
static String	slurp(Reader reader) Equivalent of slurp(InputStream) but using a reader instead of input stream.

Methods inherited from class java.lang.Object

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

Method Detail

slurp

public static byte[] slurp(InputStream stream)
                    throws RuntimeException

Reads in the entire contents of the given input stream and returns the data in a byte array. Be careful - if the stream has a lot of data, you run the risk of an OutOfMemoryError.

Parameters:

stream - the stream to read

Returns:

the stream's data

Throws:

RuntimeException - if an IO exception occurred while reading the stream

slurp

public static String slurp(Reader reader)
                    throws RuntimeException

Equivalent of slurp(InputStream) but using a reader instead of input stream.

Parameters:

reader -

Returns:

Throws:

RuntimeException

copy

public static long copy(InputStream input,
                        OutputStream output)
                 throws RuntimeException

Copies data from the input stream to the output stream. Upon completion or on an exception, the streams will be closed.

Parameters:

input - the originating stream that contains the data to be copied

output - the destination stream where the data should be copied to

Returns:

the number of bytes copied from the input to the output stream

Throws:

RuntimeException - if failed to read or write the data

copy

public static long copy(Reader rdr,
                        Writer wrt)
                 throws RuntimeException

Equivalent of copy(InputStream, OutputStream) but using reader and writer instead of streams.

Parameters:

rdr -

wrt -

Returns:

Throws:

RuntimeException

copy

public static long copy(InputStream input,
                        OutputStream output,
                        boolean closeStreams)
                 throws RuntimeException

Copies data from the input stream to the output stream. Upon completion or on an exception, the streams will be closed but only if closeStreams is true. If closeStreams is false, the streams are left open; the caller has the responsibility to close them.

Parameters:

input - the originating stream that contains the data to be copied

output - the destination stream where the data should be copied to

closeStreams - if true, the streams will be closed before the method returns

Returns:

the number of bytes copied from the input to the output stream

Throws:

RuntimeException - if failed to read or write the data

copy

public static long copy(Reader rdr,
                        Writer wrt,
                        boolean closeStreams)
                 throws RuntimeException

Equivalent of copy(InputStream, OutputStream, boolean) only using reader and writer instead of input stream and output stream.

Parameters:

rdr -

wrt -

closeStreams -

Returns:

Throws:

RuntimeException

copy

public static long copy(InputStream input,
                        OutputStream output,
                        long startByte,
                        long length)
                 throws RuntimeException

Copies data from the input stream to the output stream. The caller has the responsibility to close them. This method allows you to copy a byte range from the input stream. The start byte is the index (where the first byte of the stream is index #0) that starts to be copied. length indicates how many bytes to copy, a negative length indicates copy everything up to the EOF of the input stream.

Because this method must leave the given input stream intact in case the caller wants to continue reading from the input stream (that is, in case the caller wants to read the next byte after the final byte read by this method), this method will not wrap the input stream with a buffered input stream. Because of this, this method is less efficient than copy(InputStream, OutputStream, boolean). If you do not care to continue reading from the input stream after this method completes, it is recommended you wrap your input stream in a BufferedInputStream and pass that buffered stream to this method.

Parameters:

input - the originating stream that contains the data to be copied

output - the destination stream where the data should be copied to

startByte - the first byte to copy from the input stream (byte indexes start at #0)

length - the number of bytes to copy - if -1, then copy all until EOF

Returns:

the number of bytes copied from the input to the output stream (usually length, but if length was larger than the number of bytes in input after the start byte, this return value will be less than length.

Throws:

RuntimeException - if failed to read or write the data

serialize

public static byte[] serialize(Serializable object)
                        throws RuntimeException

Given a serializable object, this will return the object's serialized byte array representation.

Parameters:

object - the object to serialize

Returns:

the serialized bytes

Throws:

RuntimeException - if failed to serialize the object

deserialize

public static Object deserialize(byte[] serializedData)
                          throws RuntimeException

Deserializes the given serialization data and returns the object.

Parameters:

serializedData - the serialized data as a byte array

Returns:

the deserialized object

Throws:

RuntimeException - if failed to deserialize the object

safeClose

public static void safeClose(Closeable stream)

Can be used to safely close a stream. No-op if the stream is null.

Parameters:

stream - the stream to close or null