net.rim.device.api.io
Class Base64InputStream

java.lang.Object
  java.io.InputStream
      net.rim.device.api.io.Base64InputStream

public class Base64InputStream
extends InputStream

Input stream for reading Base64 encoded data.

This class implements a stream which reads in and decodes Base64 encoded data. For a description of the Base64 encoding scheme, see RFC 2045. As per RFC 2045, all input characters not in the Base64 character table are ignored.

Sample code

Example 1:

try
{
byte [] data = Base64InputStream.decode(strToDecode);
String decoded = new String(data, "UTF-8");
}
catch (IOException ioe)
{
}

Example 2:


// Decodes the given byte array from Base64.
// Offset and length specify which part of the array to decode.
// The decoded data is returned as a String.
public static String decodeBase64( byte[] toDecode, int offset, int length )
{
// Create the input byte array to pass in the content.
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream( toDecode, offset, length )

// Create the base64 input stream.
Base64InputStream base64InputStream = new Base64InputStream(byteArrayInputStream);

StringBuffer sb = new StringBuffer();
int read;
try
{
// Call read to decode the base64 content.
while ((read = base64InputStream.read()) >= 0)
{
sb.append( (char)read );
}

base64InputStream.close();
}
catch (IOException ioe)
{
return null;
}

return sb.toString();
}

Constructor Summary

Base64InputStream(InputStream inputStream)
Constructs a new Base64InputStream instance with underlying input stream.

Base64InputStream(InputStream inputStream, boolean treatErrorAsEOF)
Constructs a new Base64InputStream instance with underlying input stream.

Method Summary
int	available() Retrieves number of available bytes.
void	close() Closes this input stream.
static byte[]	decode(byte[] input, int inputOffset, int inputLength) Decode the Base64 encoded input and return the result.
static byte[]	decode(String input) Decode the Base64 encoded input and return the result.
static byte[]	decode(String input, int inputOffset, int inputLength) Decode the Base64 encoded input and return the result.
int	read() Reads one byte from this stream.
int	read(byte[] buffer) Reads some bytes from this stream.
int	read(byte[] buffer, int bufferOffset, int bufferLength) Read specified number of bytes from this stream.

Methods inherited from class java.io.InputStream

mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

Base64InputStream

public Base64InputStream(InputStream inputStream)

Constructs a new Base64InputStream instance with underlying input stream. The stream defaults to immediately throwing an IOException if a decoding error occurs, rather than treating the error as the EOF.

Parameters:

inputStream - Underlying input stream.

Base64InputStream

public Base64InputStream(InputStream inputStream,
                         boolean treatErrorAsEOF)

Constructs a new Base64InputStream instance with underlying input stream.

Parameters:

inputStream - Underlying input stream.

treatErrorAsEOF - A boolean to specify whether or not to treat a decoding error as the end of stream or to just immediately throw an IOException.

Since:

BlackBerry API 3.6.0

Method Detail

read

public int read()
         throws IOException

Reads one byte from this stream.

Invoke this method to read one byte from this stream.

Specified by:

read in class InputStream

Returns:

Decoded byte from stream, or -1 if no more data to read.

Throws:

IOException - If this stream is closed, the underlying stream has a problem, or the input data is corrupted.

read

public int read(byte[] buffer)
         throws IOException

Reads some bytes from this stream.

Invoke this method to attempt to fill a provided output parameter byte array with data from this stream.

Overrides:

read in class InputStream

Parameters:

buffer - Buffer to contain read and decoded data.

Returns:

0 if length of output parameter byte array is zero; otherwise, the number of bytes actually read into the buffer. If no more data was available when you invoked this method, it returns -1.

Throws:

IOException - If this stream is closed, the underlying stream has a problem, or the input data is corrupted.

See Also:

InputStream.read(byte[], int, int)

read

public int read(byte[] buffer,
                int bufferOffset,
                int bufferLength)
         throws IOException

Read specified number of bytes from this stream.

Overrides:

read in class InputStream

Parameters:

buffer - Buffer to contain data; must be large enough to contain desired number of bytes.

bufferOffset - First element in output parameter buffer at which to begin writing decoded data; if not 0, then output parameter buffer must be at least bufferOffset + bufferLength elements long.

bufferLength - Number of bytes to read from this stream.

Returns:

0 if length of output parameter byte array is zero; otherwise, the number of bytes actually read into the buffer. If no more data was available when you invoked this method, it returns -1.

Throws:

IOException - If this stream is closed, the underlying stream has a problem, or the input data is corrupted.

See Also:

InputStream.read()

available

public int available()
              throws IOException

Retrieves number of available bytes.

Invoke this method to find out the number of bytes you can freely read (or skip over) from this stream (that is, without being blocked by another invocation of one of this stream's methods, on this or another thread).

Overrides:

available in class InputStream

Returns:

Number of bytes freely available for reading in this stream; note that you cannot assume this value to equal the length of this stream.

Throws:

IOException - If this stream is closed.

close

public void close()
           throws IOException

Closes this input stream.

Invoke this method to close this stream and release any system resources it uses.

Overrides:

close in class InputStream

Throws:

IOException - If the underlying stream has a problem.

decode

public static byte[] decode(String input)
                     throws IOException

Decode the Base64 encoded input and return the result.

Parameters:

input - The Base64 encoded input

inputOffset - The offset into the array

inputLength - The length of the input

Returns:

A byte array containing the decoded input.

Throws:

IOException - Thrown if a decoding error occurred.

Since:

BlackBerry API 4.1.0

decode

public static byte[] decode(String input,
                            int inputOffset,
                            int inputLength)
                     throws IOException

Decode the Base64 encoded input and return the result.

Parameters:

input - The Base64 encoded input

inputOffset - The offset into the array

inputLength - The length of the input

Returns:

A byte array containing the decoded input.

Throws:

IOException - Thrown if a decoding error occurred.

Since:

BlackBerry API 4.1.0

decode

public static byte[] decode(byte[] input,
                            int inputOffset,
                            int inputLength)
                     throws IOException

Decode the Base64 encoded input and return the result.

Parameters:

input - The Base64 encoded input

inputOffset - The offset into the array

inputLength - The length of the input

Returns:

A byte array containing the decoded input.

Throws:

IOException - Thrown if a decoding error occurred.

Since:

BlackBerry API 4.0.2