ch.javasoft.jbase.util
Class AbstractDataInput

java.lang.Object
  ch.javasoft.jbase.util.AbstractDataInput

All Implemented Interfaces:

DataInput

public abstract class AbstractDataInput
extends Object
implements DataInput

The AbstractDataInput class implements most methods of DataInput, leaving only the following methods for subclasses:

• read()
• peek()
• read(byte[], int, int)
• skipBytes(int)

This class is thread safe.

Constructor Summary

AbstractDataInput()

Method Summary

protected abstract int	peek() Like read(), but the value is read again, that is, the position is not moved forward.
protected abstract int	read() Reads a byte of data from this file.
protected abstract int	read(byte[] b, int off, int len) Reads a sub array as a sequence of bytes.
boolean	readBoolean()
byte	readByte()
char	readChar()
double	readDouble()
float	readFloat()
void	readFully(byte[] b)
void	readFully(byte[] b, int off, int len)
int	readInt()
String	readLine() Note that this method throws an i/o exception if the peek() method is not supported.
long	readLong()
short	readShort()
int	readUnsignedByte()
int	readUnsignedShort()
String	readUTF()
abstract int	skipBytes(int n)

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractDataInput

public AbstractDataInput()

Method Detail

read

protected abstract int read()
                     throws IOException

Reads a byte of data from this file. The byte is returned as an integer in the range 0 to 255 (0x00-0x0ff). This method should block if no input is yet available.

Although AbstractDataInput is not a subclass of InputStream, this method behaves in exactly the same way as the InputStream.read() method of InputStream.

Returns:

the next byte of data, or -1 if the end of the input has been reached.

Throws:

IOException - if an I/O error occurs. Not thrown if end-of-file has been reached.

peek

protected abstract int peek()
                     throws IOException

Like read(), but the value is read again, that is, the position is not moved forward. This method is used by readLine(), if subclasses cannot support this method, an i/o exception should be thrown, causing that readLine() will also throw an i/o exception.

Throws:

IOException - if peek operations are not supported

read

protected abstract int read(byte[] b,
                            int off,
                            int len)
                     throws IOException

Reads a sub array as a sequence of bytes.

Parameters:

b - the buffer into which the data is read.

off - the start offset of the data.

len - the number of bytes to read.

Throws:

IOException - If an I/O error has occurred.

skipBytes

public abstract int skipBytes(int n)
                       throws IOException

Specified by:

skipBytes in interface DataInput

Throws:

IOException

readBoolean

public boolean readBoolean()
                    throws IOException

Specified by:

readBoolean in interface DataInput

Throws:

IOException

readByte

public byte readByte()
              throws IOException

Specified by:

readByte in interface DataInput

Throws:

IOException

readChar

public char readChar()
              throws IOException

Specified by:

readChar in interface DataInput

Throws:

IOException

readDouble

public double readDouble()
                  throws IOException

Specified by:

readDouble in interface DataInput

Throws:

IOException

readFloat

public float readFloat()
                throws IOException

Specified by:

readFloat in interface DataInput

Throws:

IOException

readFully

public void readFully(byte[] b)
               throws IOException

Specified by:

readFully in interface DataInput

Throws:

IOException

readFully

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

Specified by:

readFully in interface DataInput

Throws:

IOException

readInt

public int readInt()
            throws IOException

Specified by:

readInt in interface DataInput

Throws:

IOException

readLine

public String readLine()
                throws IOException

Note that this method throws an i/o exception if the peek() method is not supported.

Specified by:

readLine in interface DataInput

Throws:

IOException

See Also:

peek(), DataInput.readLine()

readLong

public long readLong()
              throws IOException

Specified by:

readLong in interface DataInput

Throws:

IOException

readShort

public short readShort()
                throws IOException

Specified by:

readShort in interface DataInput

Throws:

IOException

readUTF

public String readUTF()
               throws IOException

Specified by:

readUTF in interface DataInput

Throws:

IOException

readUnsignedByte

public int readUnsignedByte()
                     throws IOException

Specified by:

readUnsignedByte in interface DataInput

Throws:

IOException

readUnsignedShort

public int readUnsignedShort()
                      throws IOException

Specified by:

readUnsignedShort in interface DataInput

Throws:

IOException