com.google.common.io
Class LittleEndianDataOutputStream

java.lang.Object
  extended by java.io.OutputStream
      extended by java.io.FilterOutputStream
          extended by com.google.common.io.LittleEndianDataOutputStream
All Implemented Interfaces:
Closeable, DataOutput, Flushable

@Beta
public class LittleEndianDataOutputStream
extends FilterOutputStream
implements DataOutput

An implementation of DataOutput that uses little-endian byte ordering for writing char, short, int, float, double, and long values.

Note: This class intentionally violates the specification of its supertype DataOutput, which explicitly requires big-endian byte order.

Since:
8
Author:
chrisn@google.com (Chris Nokleberg), kbottner@google.com (Keith Bottner)

Field Summary
 
Fields inherited from class java.io.FilterOutputStream
out
 
Constructor Summary
LittleEndianDataOutputStream(OutputStream out)
          Creates a LittleEndianDataOutputStream that wraps the given stream.
 
Method Summary
 void write(byte[] b, int off, int len)
          Writes len bytes from the specified byte array starting at offset off to this output stream.
 void writeBoolean(boolean v)
          Writes a boolean value to this output stream.
 void writeByte(int v)
          Writes to the output stream the eight low- order bits of the argument v.
 void writeBytes(String s)
          Deprecated. The semantics of writeBytes(String s) are considered dangerous. Please use writeUTF(String s), writeChars(String s) or another write method instead.
 void writeChar(int v)
          Writes a char as specified by DataOutputStream.writeChar(int), except using little-endian byte order.
 void writeChars(String s)
          Writes a String as specified by DataOutputStream.writeChars(String), except each character is written using little-endian byte order.
 void writeDouble(double v)
          Writes a double as specified by DataOutputStream.writeDouble(double), except using little-endian byte order.
 void writeFloat(float v)
          Writes a float as specified by DataOutputStream.writeFloat(float), except using little-endian byte order.
 void writeInt(int v)
          Writes an int as specified by DataOutputStream.writeInt(int), except using little-endian byte order.
 void writeLong(long v)
          Writes a long as specified by DataOutputStream.writeLong(long), except using little-endian byte order.
 void writeShort(int v)
          Writes a short as specified by DataOutputStream.writeShort(int), except using little-endian byte order.
 void writeUTF(String str)
          Writes two bytes of length information to the output stream, followed by the modified UTF-8 representation of every character in the string s.
 
Methods inherited from class java.io.FilterOutputStream
close, flush, write, write
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface java.io.DataOutput
write, write
 

Constructor Detail

LittleEndianDataOutputStream

public LittleEndianDataOutputStream(OutputStream out)
Creates a LittleEndianDataOutputStream that wraps the given stream.

Parameters:
out - the stream to delegate to
Method Detail

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException
Description copied from class: java.io.FilterOutputStream
Writes len bytes from the specified byte array starting at offset off to this output stream.

The write method of FilterOutputStream calls the write method of one argument on each byte to output.

Note that this method does not call the write method of its underlying input stream with the same arguments. Subclasses of FilterOutputStream should provide a more efficient implementation of this method.

Specified by:
write in interface DataOutput
Overrides:
write in class FilterOutputStream
Parameters:
b - the data.
off - the start offset in the data.
len - the number of bytes to write.
Throws:
IOException - if an I/O error occurs.
See Also:
FilterOutputStream.write(int)

writeBoolean

public void writeBoolean(boolean v)
                  throws IOException
Description copied from interface: java.io.DataOutput
Writes a boolean value to this output stream. If the argument v is true, the value (byte)1 is written; if v is false, the value (byte)0 is written. The byte written by this method may be read by the readBoolean method of interface DataInput, which will then return a boolean equal to v.

Specified by:
writeBoolean in interface DataOutput
Parameters:
v - the boolean to be written.
Throws:
IOException - if an I/O error occurs.

writeByte

public void writeByte(int v)
               throws IOException
Description copied from interface: java.io.DataOutput
Writes to the output stream the eight low- order bits of the argument v. The 24 high-order bits of v are ignored. (This means that writeByte does exactly the same thing as write for an integer argument.) The byte written by this method may be read by the readByte method of interface DataInput, which will then return a byte equal to (byte)v.

Specified by:
writeByte in interface DataOutput
Parameters:
v - the byte value to be written.
Throws:
IOException - if an I/O error occurs.

writeBytes

@Deprecated
public void writeBytes(String s)
                throws IOException
Deprecated. The semantics of writeBytes(String s) are considered dangerous. Please use writeUTF(String s), writeChars(String s) or another write method instead.

Description copied from interface: java.io.DataOutput
Writes a string to the output stream. For every character in the string s, taken in order, one byte is written to the output stream. If s is null, a NullPointerException is thrown.

If s.length is zero, then no bytes are written. Otherwise, the character s[0] is written first, then s[1], and so on; the last character written is s[s.length-1]. For each character, one byte is written, the low-order byte, in exactly the manner of the writeByte method . The high-order eight bits of each character in the string are ignored.

Specified by:
writeBytes in interface DataOutput
Parameters:
s - the string of bytes to be written.
Throws:
IOException - if an I/O error occurs.

writeChar

public void writeChar(int v)
               throws IOException
Writes a char as specified by DataOutputStream.writeChar(int), except using little-endian byte order.

Specified by:
writeChar in interface DataOutput
Parameters:
v - the char value to be written.
Throws:
IOException - if an I/O error occurs

writeChars

public void writeChars(String s)
                throws IOException
Writes a String as specified by DataOutputStream.writeChars(String), except each character is written using little-endian byte order.

Specified by:
writeChars in interface DataOutput
Parameters:
s - the string value to be written.
Throws:
IOException - if an I/O error occurs

writeDouble

public void writeDouble(double v)
                 throws IOException
Writes a double as specified by DataOutputStream.writeDouble(double), except using little-endian byte order.

Specified by:
writeDouble in interface DataOutput
Parameters:
v - the double value to be written.
Throws:
IOException - if an I/O error occurs

writeFloat

public void writeFloat(float v)
                throws IOException
Writes a float as specified by DataOutputStream.writeFloat(float), except using little-endian byte order.

Specified by:
writeFloat in interface DataOutput
Parameters:
v - the float value to be written.
Throws:
IOException - if an I/O error occurs

writeInt

public void writeInt(int v)
              throws IOException
Writes an int as specified by DataOutputStream.writeInt(int), except using little-endian byte order.

Specified by:
writeInt in interface DataOutput
Parameters:
v - the int value to be written.
Throws:
IOException - if an I/O error occurs

writeLong

public void writeLong(long v)
               throws IOException
Writes a long as specified by DataOutputStream.writeLong(long), except using little-endian byte order.

Specified by:
writeLong in interface DataOutput
Parameters:
v - the long value to be written.
Throws:
IOException - if an I/O error occurs

writeShort

public void writeShort(int v)
                throws IOException
Writes a short as specified by DataOutputStream.writeShort(int), except using little-endian byte order.

Specified by:
writeShort in interface DataOutput
Parameters:
v - the short value to be written.
Throws:
IOException - if an I/O error occurs

writeUTF

public void writeUTF(String str)
              throws IOException
Description copied from interface: java.io.DataOutput
Writes two bytes of length information to the output stream, followed by the modified UTF-8 representation of every character in the string s. If s is null, a NullPointerException is thrown. Each character in the string s is converted to a group of one, two, or three bytes, depending on the value of the character.

If a character c is in the range \u0001 through \u007f, it is represented by one byte:

(byte)c 

If a character c is \u0000 or is in the range \u0080 through \u07ff, then it is represented by two bytes, to be written in the order shown:


 (byte)(0xc0 | (0x1f & (c >> 6)))
 (byte)(0x80 | (0x3f & c))
  

If a character c is in the range \u0800 through uffff, then it is represented by three bytes, to be written in the order shown:


 (byte)(0xe0 | (0x0f & (c >> 12)))
 (byte)(0x80 | (0x3f & (c >>  6)))
 (byte)(0x80 | (0x3f & c))
  

First, the total number of bytes needed to represent all the characters of s is calculated. If this number is larger than 65535, then a UTFDataFormatException is thrown. Otherwise, this length is written to the output stream in exactly the manner of the writeShort method; after this, the one-, two-, or three-byte representation of each character in the string s is written.

The bytes written by this method may be read by the readUTF method of interface DataInput , which will then return a String equal to s.

Specified by:
writeUTF in interface DataOutput
Parameters:
str - the string value to be written.
Throws:
IOException - if an I/O error occurs.