totalcross.io

Class LineReader

java.lang.Object

totalcross.io.LineReader

Direct Known Subclasses:

TokenReader

public class LineReader
extends java.lang.Object

Used to read lines ending with \r\n (enter/linefeed) or \n (linefeed) from a stream. Consecutive newlines are skipped. This class does not work well with multi-byte characters when the second byte contains the delimiter or enter/linefeed.

Here's a sample:

 LineReader reader = new LineReader(new File("text.txt",File.READ_WRITE));
 String line;
 while ((line = reader.readLine()) != null)
 {
    ... do whatever you want with the line.
 }
 

Note that this class already uses a buffer for faster detection of the newline. Don't use LineReader with a BufferedStream, it's nonsense and it will throw a warning on the desktop.

Since:

SuperWaba 5.12

Field Summary

Fields

Modifier and Type	Field and Description
boolean	doTrim Set to true to apply a trim in the string that is returned.
protected Stream	f
int	maxTries The number of times it tries to read more data if none is available.
protected int	ofs
protected ByteArrayStream	readBuf
boolean	returnEmptyLines Set to true to receive empty lines (\r\n\r\n returns "","").

Constructor Summary

Constructors

Constructor and Description
LineReader(Stream f) Constructs a new LineReader and sets maxTries accordingly to the type of class: 10 if its a Socket or a PortConnector, 0 otherwise.
LineReader(Stream f, byte[] buffer, int start, int len) Constructs a new LineReader and sets maxTries accordingly to the type of class: 10 if its a Socket or a PortConnector; 0, otherwise.

Method Summary

Modifier and Type	Method and Description
Stream	getStream() Returns the Stream attached to this LineReader.
java.lang.String	readLine() Returns the next line available on this stream or null if none.
protected boolean	readMore() Read more bytes from the stream.
protected void	reuse() Move the buffer to the beginning, in order to preserve the bytes that were not read yet.
void	setStream(Stream f) Change the initial Stream to the attached one, and fetches some data.

Methods inherited from class java.lang.Object

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

Field Detail

f

protected Stream f

readBuf

protected ByteArrayStream readBuf

ofs

protected int ofs

maxTries

public int maxTries

The number of times it tries to read more data if none is available. Defaults to 10 if the Stream is a Socket or a PortConnector; 0, otherwise.

doTrim

public boolean doTrim

Set to true to apply a trim in the string that is returned.

Since:

TotalCross 1.23

returnEmptyLines

public boolean returnEmptyLines

Set to true to receive empty lines (\r\n\r\n returns "","").

Since:

TotalCross 1.3

Constructor Detail

LineReader

public LineReader(Stream f)
           throws IOException

Constructs a new LineReader and sets maxTries accordingly to the type of class: 10 if its a Socket or a PortConnector, 0 otherwise.

Throws:

IOException

LineReader

public LineReader(Stream f,
                  byte[] buffer,
                  int start,
                  int len)
           throws IOException

Constructs a new LineReader and sets maxTries accordingly to the type of class: 10 if its a Socket or a PortConnector; 0, otherwise. The given buffer contents are added to the internal buffer to start reading from them.

Throws:

IOException

Since:

TotalCross 1.25

Method Detail

setStream

public void setStream(Stream f)
               throws IOException

Change the initial Stream to the attached one, and fetches some data. Reusing a LineReader throught this method can preserve memory.

Throws:

IOException

Since:

TotalCross 1.23

getStream

public Stream getStream()

Returns the Stream attached to this LineReader.

Since:

TotalCross 1.23

reuse

protected void reuse()

Move the buffer to the beginning, in order to preserve the bytes that were not read yet.

readMore

protected boolean readMore()
                    throws IOException

Read more bytes from the stream. If there's no data immediately to be read, it causes the current thread to yield the current use of CPU before attempting a new read, up to maxTries times.

Throws:

IOException

readLine

public java.lang.String readLine()
                          throws IOException

Returns the next line available on this stream or null if none. Empty lines are skipped by default.

Throws:

IOException