com.drew.lang
Class RandomAccessFileReader

java.lang.Object
  com.drew.lang.RandomAccessFileReader

All Implemented Interfaces:

BufferReader

public class RandomAccessFileReader
extends Object
implements BufferReader

Provides methods to read specific values from a byte array, with a consistent, checked exception structure for issues.

By default, the reader operates with Motorola byte order (big endianness). This can be changed by calling setMotorolaByteOrder(boolean).

Author:

Drew Noakes http://drewnoakes.com

Constructor Summary

RandomAccessFileReader(RandomAccessFile file)

Method Summary

byte[]	getBytes(int index, int count)
double	getDouble64(int index)
float	getFloat32(int index)
short	getInt16(int index) Returns a signed 16-bit int calculated from two bytes of data at the specified index (MSB, LSB).
int	getInt32(int index) Returns a signed 32-bit integer from four bytes of data at the specified index the buffer.
long	getInt64(int index) Get a signed 64-bit integer from the buffer.
byte	getInt8(int index) Returns a signed 8-bit int calculated from one byte of data at the specified index.
long	getLength() Returns the length of the buffer.
String	getNullTerminatedString(int index, int maxLengthBytes) Creates a String from the _data buffer starting at the specified index, and ending where byte=='\0' or where length==maxLength.
float	getS15Fixed16(int index)
String	getString(int index, int bytesRequested)
String	getString(int index, int bytesRequested, String charset)
int	getUInt16(int index) Returns an unsigned 16-bit int calculated from two bytes of data at the specified index.
long	getUInt32(int index) Get a 32-bit unsigned integer from the buffer, returning it as a long.
short	getUInt8(int index) Returns an unsigned 8-bit int calculated from one byte of data at the specified index.
boolean	isMotorolaByteOrder() Gets the endianness of this reader.
void	setMotorolaByteOrder(boolean motorolaByteOrder) Sets the endianness of this reader.

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomAccessFileReader

public RandomAccessFileReader(RandomAccessFile file)
                       throws IOException

Throws:

IOException

Method Detail

getLength

public long getLength()

Description copied from interface: BufferReader

Returns the length of the buffer. This value represents the total number of bytes in the underlying source.

Specified by:

getLength in interface BufferReader

Returns:

The number of bytes in the buffer.

setMotorolaByteOrder

public void setMotorolaByteOrder(boolean motorolaByteOrder)

Description copied from interface: BufferReader

Sets the endianness of this reader.

• true for Motorola (or big) endianness
• false for Intel (or little) endianness

Specified by:

setMotorolaByteOrder in interface BufferReader

Parameters:

motorolaByteOrder - true for motorola/big endian, false for intel/little endian

isMotorolaByteOrder

public boolean isMotorolaByteOrder()

Description copied from interface: BufferReader

Gets the endianness of this reader.

• true for Motorola (or big) endianness
• false for Intel (or little) endianness

Specified by:

isMotorolaByteOrder in interface BufferReader

getUInt8

public short getUInt8(int index)
               throws BufferBoundsException

Description copied from interface: BufferReader

Returns an unsigned 8-bit int calculated from one byte of data at the specified index.

Specified by:

getUInt8 in interface BufferReader

Parameters:

index - position within the data buffer to read byte

Returns:

the 8 bit int value, between 0 and 255

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getInt8

public byte getInt8(int index)
             throws BufferBoundsException

Description copied from interface: BufferReader

Returns a signed 8-bit int calculated from one byte of data at the specified index.

Specified by:

getInt8 in interface BufferReader

Parameters:

index - position within the data buffer to read byte

Returns:

the 8 bit int value, between 0x00 and 0xFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getUInt16

public int getUInt16(int index)
              throws BufferBoundsException

Description copied from interface: BufferReader

Returns an unsigned 16-bit int calculated from two bytes of data at the specified index.

Specified by:

getUInt16 in interface BufferReader

Parameters:

index - position within the data buffer to read first byte

Returns:

the 16 bit int value, between 0x0000 and 0xFFFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getInt16

public short getInt16(int index)
               throws BufferBoundsException

Description copied from interface: BufferReader

Returns a signed 16-bit int calculated from two bytes of data at the specified index (MSB, LSB).

Specified by:

getInt16 in interface BufferReader

Parameters:

index - position within the data buffer to read first byte

Returns:

the 16 bit int value, between 0x0000 and 0xFFFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getUInt32

public long getUInt32(int index)
               throws BufferBoundsException

Description copied from interface: BufferReader

Get a 32-bit unsigned integer from the buffer, returning it as a long.

Specified by:

getUInt32 in interface BufferReader

Parameters:

index - position within the data buffer to read first byte

Returns:

the unsigned 32-bit int value as a long, between 0x00000000 and 0xFFFFFFFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getInt32

public int getInt32(int index)
             throws BufferBoundsException

Description copied from interface: BufferReader

Returns a signed 32-bit integer from four bytes of data at the specified index the buffer.

Specified by:

getInt32 in interface BufferReader

Parameters:

index - position within the data buffer to read first byte

Returns:

the signed 32 bit int value, between 0x00000000 and 0xFFFFFFFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getInt64

public long getInt64(int index)
              throws BufferBoundsException

Description copied from interface: BufferReader

Get a signed 64-bit integer from the buffer.

Specified by:

getInt64 in interface BufferReader

Parameters:

index - position within the data buffer to read first byte

Returns:

the 64 bit int value, between 0x0000000000000000 and 0xFFFFFFFFFFFFFFFF

Throws:

BufferBoundsException - the buffer does not contain enough bytes to service the request, or index is negative

getS15Fixed16

public float getS15Fixed16(int index)
                    throws BufferBoundsException

Specified by:

getS15Fixed16 in interface BufferReader

Throws:

BufferBoundsException

getFloat32

public float getFloat32(int index)
                 throws BufferBoundsException

Specified by:

getFloat32 in interface BufferReader

Throws:

BufferBoundsException

getDouble64

public double getDouble64(int index)
                   throws BufferBoundsException

Specified by:

getDouble64 in interface BufferReader

Throws:

BufferBoundsException

getBytes

public byte[] getBytes(int index,
                       int count)
                throws BufferBoundsException

Specified by:

getBytes in interface BufferReader

Throws:

BufferBoundsException

getString

public String getString(int index,
                        int bytesRequested)
                 throws BufferBoundsException

Specified by:

getString in interface BufferReader

Throws:

BufferBoundsException

getString

public String getString(int index,
                        int bytesRequested,
                        String charset)
                 throws BufferBoundsException

Specified by:

getString in interface BufferReader

Throws:

BufferBoundsException

getNullTerminatedString

public String getNullTerminatedString(int index,
                                      int maxLengthBytes)
                               throws BufferBoundsException

Description copied from interface: BufferReader

Creates a String from the _data buffer starting at the specified index, and ending where byte=='\0' or where length==maxLength.

Specified by:

getNullTerminatedString in interface BufferReader

Parameters:

index - The index within the buffer at which to start reading the string.

maxLengthBytes - The maximum number of bytes to read. If a zero-byte is not reached within this limit, reading will stop and the string will be truncated to this length.

Returns:

The read string.

Throws:

BufferBoundsException - The buffer does not contain enough bytes to satisfy this request.