structure
Class ReadStream

java.lang.Object
  |
  +--java.io.InputStream
        |
        +--java.io.FilterInputStream
              |
              +--structure.ReadStream

public class ReadStream

extends FilterInputStream

A ReadStream provides reasonable access to the typewritten data on an input stream. Usually, a ReadStream is constructed with no parameters, causing the ReadStream to open access to System.in.

The access methods allow one to read from the stream, much as is done with Pascal.

Typical usage:

To read everything typed in System.in into a vector we could use the following:

 public static void main(String[] argv){
	ReadStream r = new ReadStream();
	Vector buffer = new Vector();
	while(!r.eof()){
	    buffer.add(r.readString());
	}
	System.out.println(buffer);
	System.out.println(buffer.size());
   }
 }
 

Field Summary

protected boolean	absorbNL Whether or not accept the CR as part of previous newline.
protected boolean	atEOF True iff we've seen the end-of-file
protected char[]	buffer The buffer to hold pushback characters
protected int	buffersize The number of characters to be stored in buffer.
protected int	buffertop
protected DataInputStream	strm The underlying data stream.

Fields inherited from class java.io.FilterInputStream

in

Fields inherited from class java.io.InputStream

SKIP_BUFFER_SIZE, skipBuffer

Constructor Summary

ReadStream()
Construct an empty ReadStream, obtaining info from System.in.

ReadStream(InputStream strm)
Construct a ReadStream based on pre-existing input stream.

Method Summary

private boolean	acceptChar(char c)
private boolean	acceptWord(String s)
boolean	eof() Determine if we've seen end-of-file.
boolean	eoln() Return true if the next character to be read is an end-of-line mark.
char	getFirst() Read (but don't consume) next char in stream.
private static boolean	isWhite(char c)
void	pushbackChar(char c) Return character to input stream for reading at later time.
boolean	readBoolean() Read the next word "true" or "false" as a boolean.
char	readChar() Read next character, whitespace or not.
double	readDouble() Reads the next double value from input stream.
float	readFloat() Read floating point value from input (Currently not working).
void	readFully(byte[] b) Read an array of bytes from input.
void	readFully(byte[] b, int off, int len) Read input into byte array.
int	readInt() Reads an integer from input stream.
String	readLine() Read the remainder of line, including end-of-line mark.
void	readln() Read characters up to and including the end-of-line mark.
long	readLong() Read a (potentially long) input.
short	readShort() Reads an integer from input stream.
String	readString() Skip white space and read in the next non-whitespace word as a string.
String	readUTF() Read unicode from input.
void	skipWhite() Consume all the white-space characters until EOF or other data.

Methods inherited from class java.io.FilterInputStream

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

Methods inherited from class java.lang.Object

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

Field Detail

strm

protected DataInputStream strm

The underlying data stream.

atEOF

protected boolean atEOF

True iff we've seen the end-of-file

buffer

protected char[] buffer

The buffer to hold pushback characters

buffersize

protected int buffersize

The number of characters to be stored in buffer.

buffertop

protected int buffertop

absorbNL

protected boolean absorbNL

Whether or not accept the CR as part of previous newline.

Constructor Detail

ReadStream

public ReadStream()

Construct an empty ReadStream, obtaining info from System.in.

ReadStream

public ReadStream(InputStream strm)

Construct a ReadStream based on pre-existing input stream.

Parameters:

strm - The pre-existing input stream.

Method Detail

eof

public boolean eof()

Determine if we've seen end-of-file.

Precondition:

are we at the end-of-file?

Returns:

True if the next character to be read is EOF.

isWhite

private static boolean isWhite(char c)

getFirst

public char getFirst()

Read (but don't consume) next char in stream.

Postcondition:

returns next character in stream, without consuming it

Returns:

The next character to be read.

eoln

public boolean eoln()

Return true if the next character to be read is an end-of-line mark.

Postcondition:

returns true if next stream char is an eoln char

Returns:

True iff the next character is an end-of-line mark.

readln

public void readln()

Read characters up to and including the end-of-line mark.

Postcondition:

reads input stream until end-of-line (\r or \n)

skipWhite

public void skipWhite()

Consume all the white-space characters until EOF or other data.

Postcondition:

input pointer is at EOF, or nonwhitespace char

readString

public String readString()

Skip white space and read in the next non-whitespace word as a string.

Postcondition:

reads next word as a string

Returns:

The next word on the input.

acceptChar

private boolean acceptChar(char c)

acceptWord

private boolean acceptWord(String s)

readBoolean

public boolean readBoolean()

Read the next word "true" or "false" as a boolean.

Postcondition:

returns next boolean value read from input

Returns:

The value true or false, depending on input.

readChar

public char readChar()

Read next character, whitespace or not. Fail on eof.

Postcondition:

returns next character, or 0 for eof

Returns:

The next character, or the value 0 indicating EOF.

pushbackChar

public void pushbackChar(char c)

Return character to input stream for reading at later time.

Parameters:

c - The character to push back onto input stream.

Postcondition:

pushes back character, possibly clearing EOF; if c == 0, does nothing

readDouble

public double readDouble()

Reads the next double value from input stream. Whitespace is skipped beforehand. CURRENTLY NOT WORKING.

Postcondition:

reads in double value

Returns:

The next double found on input.

readFloat

public float readFloat()

Read floating point value from input (Currently not working). Skips whitespace before reading.

Postcondition:

reads floating point value and returns value

Returns:

Next floating point number.

readFully

public void readFully(byte[] b)
               throws IOException

Read an array of bytes from input.

Parameters:

b - The array of bytes; holds result.

readFully

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

Read input into byte array.

Parameters:

b - Target array of bytes.

off - Offset into byte array to start reading.

len - Number of bytes to be read.

readShort

public short readShort()

Reads an integer from input stream.

Postcondition:

reads a short integer from stream

Returns:

The integer read form input.

readInt

public int readInt()

Reads an integer from input stream.

Postcondition:

reads an integer from stream

Returns:

The integer read form input.

readLong

public long readLong()

Read a (potentially long) input.

Postcondition:

reads a long integer from stream

Returns:

The integer read from input.

readLine

public String readLine()

Read the remainder of line, including end-of-line mark.

Postcondition:

reads remainder of line, returns as string

Returns:

The string containing all the characters to end-of-line.

readUTF

public String readUTF()
               throws IOException

Read unicode from input.

Returns:

String version of UTF character.