Package totalcross.io

Class DataStreamLE

java.lang.Object

totalcross.io.Stream

totalcross.io.DataStream

totalcross.io.DataStreamLE

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class DataStreamLE
extends DataStream

DataStreamLE can be attached to any Stream such as a PortConnector, PDBFile, or ByteArrayStream, which lets you read and write standard Java data types like int, double, and String in a simple manner. Here's an example:

 PortConnector port = new PortConnector(9600, 0);
 DataStream ds = new DataStream(port);
 ds.writeString("Hello");
 int status = ds.readUnsignedByte();
 if (status == 1)
 {
    ds.writeString("Pi");
    ds.writeDouble(3.14);
 }
 port.close();
 

Important!: All methods read and write numeric data in the little endian format (Intel format). For more information, see this.

See Also:

DataStream

Field Summary

Fields inherited from class totalcross.io.DataStream

buffer, EOSMessage, stream, zeros

Fields inherited from class totalcross.io.Stream

skipBuffer

Constructor Summary

Constructors

Constructor	Description
DataStreamLE(Stream stream)	Constructs a new DataStreamLE which sits upon the given stream using litle endian notation for multibyte values.

Method Summary

Modifier and Type	Method	Description
char	readChar()	Reads a two-byte character.
void	readChars(char[] chars, int len)	Reads a char array with the given length.
protected char[]	readChars(int len)	Reads a char array with the given length.
int	readInt()	Reads an integer from the stream as four bytes.
long	readLong()	Reads a long.
short	readShort()	Reads a short from the stream as two bytes.
int	readUnsignedShort()	Reads an unsigned short from the stream as two bytes.
int	writeChar(char c)	Writes a two-byte character.
int	writeChars(char[] chars, int start, int len, int lenSize)	Writes the given char array, writting the length as an int or as a short or as a byte or don't writting the length, depending on the number of bytes given (4,2,1,0).
int	writeChars(java.lang.String s, int len)	Writes the String as a char array.
int	writeInt(int i)	Writes an integer to the stream as four bytes.
int	writeLong(long l)	Writes a long.
int	writeShort(int i)	Writes a short to the stream as two bytes.

Methods inherited from class totalcross.io.DataStream

close, getStream, pad, readBigChars, readBigString, readBoolean, readByte, readBytes, readBytes, readBytesInternal, readChars, readChars, readCString, readDouble, readFixedString, readFloat, readObject, readSmallString, readString, readStringArray, readStringArray, readUnsignedByte, readUnsignedInt, skip, writeBigChars, writeBigString, writeBoolean, writeByte, writeByte, writeBytes, writeBytes, writeBytesInternal, writeChars, writeCString, writeDouble, writeFixedString, writeFixedString, writeFloat, writeObject, writeSmallString, writeSmallString8, writeString, writeStringArray

Methods inherited from class totalcross.io.Stream

asInputStream, asOutputStream, asStream, asStream, skipBytes, wrapInputStream, wrapInputStreamToStream, write, writeBytes, writeBytes

Methods inherited from class java.lang.Object

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

Constructor Detail

DataStreamLE

public DataStreamLE(Stream stream)

Constructs a new DataStreamLE which sits upon the given stream using litle endian notation for multibyte values.

Parameters:

stream - the base stream

Method Detail

readInt

public int readInt()
            throws EOFException,
                   IOException

Description copied from class: DataStream

Reads an integer from the stream as four bytes. The returned value will range from -2147483648 to 2147483647.

Overrides:

readInt in class DataStream

Returns:

the integer value

Throws:

EOFException

IOException

readShort

public short readShort()
                throws EOFException,
                       IOException

Description copied from class: DataStream

Reads a short from the stream as two bytes. The returned value will range from -32768 to 32767.

Overrides:

readShort in class DataStream

Returns:

the short value

Throws:

EOFException

IOException

readLong

public long readLong()
              throws EOFException,
                     IOException

Description copied from class: DataStream

Reads a long.

Overrides:

readLong in class DataStream

Returns:

the long value

Throws:

EOFException

IOException

readUnsignedShort

public int readUnsignedShort()
                      throws EOFException,
                             IOException

Description copied from class: DataStream

Reads an unsigned short from the stream as two bytes. The returned value will range from 0 to 65535. Use writeShort to write the unsigned short.

Overrides:

readUnsignedShort in class DataStream

Returns:

the short

Throws:

EOFException

IOException

See Also:

DataStream.writeShort(int)

writeInt

public int writeInt(int i)
             throws IOException

Description copied from class: DataStream

Writes an integer to the stream as four bytes.

Overrides:

writeInt in class DataStream

Parameters:

i - the integer to write

Returns:

the number of bytes written: 4

Throws:

IOException

writeShort

public int writeShort(int i)
               throws IOException

Description copied from class: DataStream

Writes a short to the stream as two bytes.

Overrides:

writeShort in class DataStream

Parameters:

i - the short to write

Returns:

the number of bytes written: 2

Throws:

IOException

writeLong

public int writeLong(long l)
              throws IOException

Description copied from class: DataStream

Writes a long.

Overrides:

writeLong in class DataStream

Throws:

IOException

readChar

public char readChar()
              throws EOFException,
                     IOException

Description copied from class: DataStream

Reads a two-byte character.

Overrides:

readChar in class DataStream

Throws:

EOFException

IOException

writeChar

public int writeChar(char c)
              throws IOException

Description copied from class: DataStream

Writes a two-byte character.

Overrides:

writeChar in class DataStream

Parameters:

c - the character to be written.

Returns:

the number of bytes written: 2

Throws:

IOException

readChars

public void readChars(char[] chars,
                      int len)
               throws EOFException,
                      IOException

Reads a char array with the given length.

Overrides:

readChars in class DataStream

Parameters:

chars - An already created chars array.

len - The array length.

Throws:

EOFException

IOException

Since:

TotalCross 1.01

readChars

protected char[] readChars(int len)
                    throws EOFException,
                           IOException

Description copied from class: DataStream

Reads a char array with the given length.

Overrides:

readChars in class DataStream

Returns:

Throws:

EOFException

IOException

writeChars

public int writeChars(char[] chars,
                      int start,
                      int len,
                      int lenSize)
               throws IOException

Description copied from class: DataStream

Writes the given char array, writting the length as an int or as a short or as a byte or don't writting the length, depending on the number of bytes given (4,2,1,0).

Overrides:

writeChars in class DataStream

Throws:

IOException

writeChars

public int writeChars(java.lang.String s,
                      int len)
               throws IOException

Description copied from class: DataStream

Writes the String as a char array. The chars are read using the charAt method from the String class. This method is faster than the other writeChars method on blackberry, but slower on other devices.

The char array size is limited to 65535 characters.

Overrides:

writeChars in class DataStream

Parameters:

s - The String to be written. Must not be null!

len - The maximum number of chars to be written. Must be less than the String's length.

Throws:

IOException