org.apache.cassandra.io.util
Class AbstractDataInput

java.lang.Object
  extended by java.io.InputStream
      extended by org.apache.cassandra.io.util.AbstractDataInput
All Implemented Interfaces:
java.io.Closeable, java.io.DataInput
Direct Known Subclasses:
MappedFileDataInput

public abstract class AbstractDataInput
extends java.io.InputStream
implements java.io.DataInput


Constructor Summary
AbstractDataInput()
           
 
Method Summary
protected abstract  int getPosition()
           
 boolean readBoolean()
          Reads a boolean from the current position in this file.
 byte readByte()
          Reads an 8-bit byte from the current position in this file.
 char readChar()
          Reads a 16-bit character from the current position in this file.
 double readDouble()
          Reads a 64-bit double from the current position in this file.
 float readFloat()
          Reads a 32-bit float from the current position in this file.
 void readFully(byte[] buffer)
          Reads bytes from this file into buffer.
 void readFully(byte[] buffer, int offset, int count)
          Read bytes from this file into buffer starting at offset offset.
 int readInt()
          Reads a 32-bit integer from the current position in this file.
 java.lang.String readLine()
          Reads a line of text form the current position in this file.
 long readLong()
          Reads a 64-bit long from the current position in this file.
 short readShort()
          Reads a 16-bit short from the current position in this file.
 int readUnsignedByte()
          Reads an unsigned 8-bit byte from the current position in this file and returns it as an integer.
 int readUnsignedShort()
          Reads an unsigned 16-bit short from the current position in this file and returns it as an integer.
 java.lang.String readUTF()
          Reads a string that is encoded in modified UTF-8 from this file.
protected abstract  void seekInternal(int position)
           
 
Methods inherited from class java.io.InputStream
available, close, mark, markSupported, read, read, read, reset, skip
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface java.io.DataInput
skipBytes
 

Constructor Detail

AbstractDataInput

public AbstractDataInput()
Method Detail

seekInternal

protected abstract void seekInternal(int position)

getPosition

protected abstract int getPosition()

readBoolean

public final boolean readBoolean()
                          throws java.io.IOException
Reads a boolean from the current position in this file. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:
readBoolean in interface java.io.DataInput
Returns:
the next boolean value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readByte

public final byte readByte()
                    throws java.io.IOException
Reads an 8-bit byte from the current position in this file. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:
readByte in interface java.io.DataInput
Returns:
the next signed 8-bit byte value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readChar

public final char readChar()
                    throws java.io.IOException
Reads a 16-bit character from the current position in this file. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readChar in interface java.io.DataInput
Returns:
the next char value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readDouble

public final double readDouble()
                        throws java.io.IOException
Reads a 64-bit double from the current position in this file. Blocks until eight bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readDouble in interface java.io.DataInput
Returns:
the next double value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readFloat

public final float readFloat()
                      throws java.io.IOException
Reads a 32-bit float from the current position in this file. Blocks until four bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readFloat in interface java.io.DataInput
Returns:
the next float value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readFully

public void readFully(byte[] buffer)
               throws java.io.IOException
Reads bytes from this file into buffer. Blocks until buffer.length number of bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readFully in interface java.io.DataInput
Parameters:
buffer - the buffer to read bytes into.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.
java.lang.NullPointerException - if buffer is null.

readFully

public void readFully(byte[] buffer,
                      int offset,
                      int count)
               throws java.io.IOException
Read bytes from this file into buffer starting at offset offset. This method blocks until count number of bytes have been read.

Specified by:
readFully in interface java.io.DataInput
Parameters:
buffer - the buffer to read bytes into.
offset - the initial position in buffer to store the bytes read from this file.
count - the maximum number of bytes to store in buffer.
Throws:
java.io.EOFException - if the end of this file is detected.
java.lang.IndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is greater than the length of buffer.
java.io.IOException - if this file is closed or another I/O error occurs.
java.lang.NullPointerException - if buffer is null.

readInt

public final int readInt()
                  throws java.io.IOException
Reads a 32-bit integer from the current position in this file. Blocks until four bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readInt in interface java.io.DataInput
Returns:
the next int value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readLine

public final java.lang.String readLine()
                                throws java.io.IOException
Reads a line of text form the current position in this file. A line is represented by zero or more characters followed by '\n', '\r', "\r\n" or the end of file marker. The string does not include the line terminating sequence.

Blocks until a line terminating sequence has been read, the end of the file is reached or an exception is thrown.

Specified by:
readLine in interface java.io.DataInput
Returns:
the contents of the line or null if no characters have been read before the end of the file has been reached.
Throws:
java.io.IOException - if this file is closed or another I/O error occurs.

readLong

public final long readLong()
                    throws java.io.IOException
Reads a 64-bit long from the current position in this file. Blocks until eight bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readLong in interface java.io.DataInput
Returns:
the next long value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readShort

public final short readShort()
                      throws java.io.IOException
Reads a 16-bit short from the current position in this file. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readShort in interface java.io.DataInput
Returns:
the next short value from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readUnsignedByte

public final int readUnsignedByte()
                           throws java.io.IOException
Reads an unsigned 8-bit byte from the current position in this file and returns it as an integer. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:
readUnsignedByte in interface java.io.DataInput
Returns:
the next unsigned byte value from this file as an int.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readUnsignedShort

public final int readUnsignedShort()
                            throws java.io.IOException
Reads an unsigned 16-bit short from the current position in this file and returns it as an integer. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readUnsignedShort in interface java.io.DataInput
Returns:
the next unsigned short value from this file as an int.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.

readUTF

public final java.lang.String readUTF()
                               throws java.io.IOException
Reads a string that is encoded in modified UTF-8 from this file. The number of bytes that must be read for the complete string is determined by the first two bytes read from the file. Blocks until all required bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:
readUTF in interface java.io.DataInput
Returns:
the next string encoded in modified UTF-8 from this file.
Throws:
java.io.EOFException - if the end of this file is detected.
java.io.IOException - if this file is closed or another I/O error occurs.
java.io.UTFDataFormatException - if the bytes read cannot be decoded into a character string.


Copyright © 2011 The Apache Software Foundation