Class HttpInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

sunlabs.brazil.util.http.HttpInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class HttpInputStream
extends FilterInputStream

This class is an input stream that provides added methods that are of help when reading the result of an HTTP request. By setting up this input stream, the user can conveniently read lines of text and copy the contents of an input stream to an output stream.

The underlying assumption of this class is that when reading the result of an HTTP request, each byte in the input stream represents an 8-bit ASCII character, and as such, it is perfectly valid to treat each byte as a character. Locale-based conversion is not appropriate in this circumstance, so the java.io.BufferedReader.readLine method should not be used.

Version:

2.2

Author:

Colin Stevens (colin.stevens@sun.com)

Field Summary

Fields

Modifier and Type	Field	Description
static int	defaultBufsize	The default size of the temporary buffer used when copying from an input stream to an output stream.

Fields inherited from class FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
HttpInputStream(InputStream in)	Creates a new HttpInputStream that reads its input from the specified input stream.

Method Summary

Modifier and Type	Method	Description
int	copyTo(OutputStream out)	Copies bytes from this input stream to the specified output stream until end of the input stream is reached.
int	copyTo(OutputStream out, int len)	Copies bytes from this input stream to the specified output stream until the specified number of bytes are copied or the end of the input stream is reached.
int	copyTo(OutputStream out, int len, byte[] buf)	Copies bytes from this input stream to the specified output stream until the specified number of bytes are copied or the end of the input stream is reached.
int	readFully(byte[] buf)	Reads buf.length bytes from the input stream.
int	readFully(byte[] buf, int off, int len)	Reads the specified number of bytes from the input stream.
String	readLine()	Reads the next line of text from the input stream.
String	readLine(int limit)	Reads the next line of text from the input stream, up to the limit specified.

Methods inherited from class FilterInputStream

available, close, mark, markSupported, read, read, read, reset, skip

Methods inherited from class InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class Object

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

Field Details

defaultBufsize

public static int defaultBufsize

The default size of the temporary buffer used when copying from an input stream to an output stream.

See Also:

• copyTo(OutputStream, int, byte[])

Constructor Details

HttpInputStream

public HttpInputStream(InputStream in)

Creates a new HttpInputStream that reads its input from the specified input stream.

Parameters:

in - The underlying input stream.

Method Details

readLine

public String readLine()
                throws IOException

Reads the next line of text from the input stream.

A line is terminated by "\r", "\n", "\r\n", or the end of the input stream. The line-terminating characters are discarded.

Returns:

The next line from the input stream, or null if the end of the input stream is reached and no bytes were found.

Throws:

IOException - if the underlying input stream throws an IOException while being read.

readLine

public String readLine(int limit)
                throws IOException

Reads the next line of text from the input stream, up to the limit specified.

A line is terminated by "\r", "\n", "\r\n", the end of the input stream, or when the specified number of characters have been read. The line-terminating characters are discarded. It is not possible to distinguish, based on the result, between a line that was exactly limit characters long and a line that was terminated because limit characters were read.

Returns:

The next line from the input stream, or null if the end of the input stream is reached and no bytes were found.

Throws:

IOException - if the underlying input stream throws an IOException while being read.

readFully

public int readFully(byte[] buf)
              throws IOException

Reads buf.length bytes from the input stream. This method reads repeatedly from the input stream until the specified number of bytes have been read or the end of the input stream is reached.

The standard InputStream.read method will generally return less than the specified number of bytes if the underlying input stream is "bursty", such as from a network source. Sometimes it is important to read the exact number of bytes desired.

Parameters:

buf - Buffer in which the data is stored. If buffer is of length 0, this method will return immediately.

Returns:

The number of bytes read. This will be less than buf.length if the end of the input stream was reached.

Throws:

IOException - if the underlying input stream throws an IOException while being read.

readFully

public int readFully(byte[] buf,
 int off,
 int len)
              throws IOException

Reads the specified number of bytes from the input stream. This method reads repeatedly from the input stream until the specified number of bytes have been read or the end of the input stream is reached.

The standard InputStream.read method will generally return less than the specified number of bytes if the underlying input stream is "bursty", such as from a network source. Sometimes it is important to read the exact number of bytes desired.

Parameters:

buf - Buffer in which the data is stored.

off - The starting offset into the buffer.

len - The number of bytes to read.

Returns:

The number of bytes read. This will be less than len if the end of the input stream was reached.

Throws:

IOException - if the underlying input stream throws an IOException while being read.

copyTo

public int copyTo(OutputStream out)
           throws IOException

Copies bytes from this input stream to the specified output stream until end of the input stream is reached.

Parameters:

out - The output stream to copy the data to.

Returns:

The number of bytes copied to the output stream.

Throws:

IOException - if the underlying input stream throws an IOException while being read or if the output stream throws an IOException while being written. It may not be possible to distinguish amongst the two conditions.

copyTo

public int copyTo(OutputStream out,
 int len)
           throws IOException

Copies bytes from this input stream to the specified output stream until the specified number of bytes are copied or the end of the input stream is reached.

Parameters:

out - The output stream to copy the data to.

len - The number of bytes to copy, or invalid input: '<' 0 to copy until the end of this stream.

Returns:

The number of bytes copied to the output stream.

Throws:

IOException - if the underlying input stream throws an IOException while being read or if the output stream throws an IOException while being written. It may not be possible to distinguish amongst the two conditions.

copyTo

public int copyTo(OutputStream out,
 int len,
 byte[] buf)
           throws IOException

Copies bytes from this input stream to the specified output stream until the specified number of bytes are copied or the end of the input stream is reached.

Parameters:

out - The output stream to copy the data to.

len - The number of bytes to copy, or invalid input: '<' 0 to copy until the end of this stream.

buf - The buffer used to for holding the temporary results while copying data from this input stream to the output stream. May be null to allow this method copy in chunks of length defaultBufsize.

Returns:

The number of bytes read from the input stream, and copied to the output stream.

Throws:

IOException - if the underlying input stream throws an IOException while being read.