public DataOutputStream(OutputStream out) 
{
        super(out);
}

Creates a new data output stream to write data to the specified underlying output stream. The counter written is set to zero.

Parameters:

out - the underlying output stream, to be saved for later use.

Also see:

java.io.FilterOutputStream#out

 public  void flush() throws IOException 
{
        out.flush();
}

Flushes this data output stream. This forces any buffered output bytes to be written out to the stream.

The flush method of DataOutputStream calls the flush method of its underlying output stream.

 public final int size() 
{
        return written;
}

Returns the current value of the counter written, the number of bytes written to this data output stream so far. If the counter overflows, it will be wrapped to Integer.MAX_VALUE.

 public synchronized  void write(int b) throws IOException 
{
        out.write(b);
        incCount(1);
}

Writes the specified byte (the low eight bits of the argument b) to the underlying output stream. If no exception is thrown, the counter written is incremented by 1.

Implements the write method of OutputStream.

 public synchronized  void write(byte[] b,
    int off,
    int len) throws IOException 
{
        out.write(b, off, len);
        incCount(len);
}

Writes len bytes from the specified byte array starting at offset off to the underlying output stream. If no exception is thrown, the counter written is incremented by len.

 public final  void writeBoolean(boolean v) throws IOException 
{
        out.write(v ? 1 : 0);
        incCount(1);
}

Writes a boolean to the underlying output stream as a 1-byte value. The value true is written out as the value (byte)1; the value false is written out as the value (byte)0. If no exception is thrown, the counter written is incremented by 1.

 public final  void writeByte(int v) throws IOException 
{
        out.write(v);
        incCount(1);
}

Writes out a byte to the underlying output stream as a 1-byte value. If no exception is thrown, the counter written is incremented by 1.

 public final  void writeBytes(String s) throws IOException 
{
        int len = s.length();
        for (int i = 0 ; i <  len ; i++) {
            out.write((byte)s.charAt(i));
        }
        incCount(len);
}

Writes out the string to the underlying output stream as a sequence of bytes. Each character in the string is written out, in sequence, by discarding its high eight bits. If no exception is thrown, the counter written is incremented by the length of s.

 public final  void writeChar(int v) throws IOException 
{
        out.write((v  > > > 8) & 0xFF);
        out.write((v  > > > 0) & 0xFF);
        incCount(2);
}

Writes a char to the underlying output stream as a 2-byte value, high byte first. If no exception is thrown, the counter written is incremented by 2.

 public final  void writeChars(String s) throws IOException 
{
        int len = s.length();
        for (int i = 0 ; i <  len ; i++) {
            int v = s.charAt(i);
            out.write((v  > > > 8) & 0xFF);
            out.write((v  > > > 0) & 0xFF);
        }
        incCount(len * 2);
}

Writes a string to the underlying output stream as a sequence of characters. Each character is written to the data output stream as if by the writeChar method. If no exception is thrown, the counter written is incremented by twice the length of s.

 public final  void writeDouble(double v) throws IOException 
{
        writeLong(Double.doubleToLongBits(v));
}

Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the underlying output stream as an 8-byte quantity, high byte first. If no exception is thrown, the counter written is incremented by 8.

 public final  void writeFloat(float v) throws IOException 
{
        writeInt(Float.floatToIntBits(v));
}

Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the underlying output stream as a 4-byte quantity, high byte first. If no exception is thrown, the counter written is incremented by 4.

 public final  void writeInt(int v) throws IOException 
{
        out.write((v  > > > 24) & 0xFF);
        out.write((v  > > > 16) & 0xFF);
        out.write((v  > > >  8) & 0xFF);
        out.write((v  > > >  0) & 0xFF);
        incCount(4);
}

Writes an int to the underlying output stream as four bytes, high byte first. If no exception is thrown, the counter written is incremented by 4.

 public final  void writeLong(long v) throws IOException 
{
        writeBuffer[0] = (byte)(v  > > > 56);
        writeBuffer[1] = (byte)(v  > > > 48);
        writeBuffer[2] = (byte)(v  > > > 40);
        writeBuffer[3] = (byte)(v  > > > 32);
        writeBuffer[4] = (byte)(v  > > > 24);
        writeBuffer[5] = (byte)(v  > > > 16);
        writeBuffer[6] = (byte)(v  > > >  8);
        writeBuffer[7] = (byte)(v  > > >  0);
        out.write(writeBuffer, 0, 8);
        incCount(8);
}

Writes a long to the underlying output stream as eight bytes, high byte first. In no exception is thrown, the counter written is incremented by 8.

 public final  void writeShort(int v) throws IOException 
{
        out.write((v  > > > 8) & 0xFF);
        out.write((v  > > > 0) & 0xFF);
        incCount(2);
}

Writes a short to the underlying output stream as two bytes, high byte first. If no exception is thrown, the counter written is incremented by 2.

 public final  void writeUTF(String str) throws IOException 
{
        writeUTF(str, this);
}

Writes a string to the underlying output stream using modified UTF-8 encoding in a machine-independent manner.

First, two bytes are written to the output stream as if by the writeShort method giving the number of bytes to follow. This value is the number of bytes actually written out, not the length of the string. Following the length, each character of the string is output, in sequence, using the modified UTF-8 encoding for the character. If no exception is thrown, the counter written is incremented by the total number of bytes written to the output stream. This will be at least two plus the length of str, and at most two plus thrice the length of str.

 static int writeUTF(String str,
    DataOutput out) throws IOException 
{
        int strlen = str.length();
        int utflen = 0;
        int c, count = 0;
        /* use charAt instead of copying String to char array */
        for (int i = 0; i <  strlen; i++) {
            c = str.charAt(i);
            if ((c  >= 0x0001) && (c < = 0x007F)) {
                utflen++;
            } else if (c  > 0x07FF) {
                utflen += 3;
            } else {
                utflen += 2;
            }
        }
        if (utflen  > 65535)
            throw new UTFDataFormatException(
                "encoded string too long: " + utflen + " bytes");
        byte[] bytearr = null;
        if (out instanceof DataOutputStream) {
            DataOutputStream dos = (DataOutputStream)out;
            if(dos.bytearr == null || (dos.bytearr.length <  (utflen+2)))
                dos.bytearr = new byte[(utflen*2) + 2];
            bytearr = dos.bytearr;
        } else {
            bytearr = new byte[utflen+2];
        }
        bytearr[count++] = (byte) ((utflen  > > > 8) & 0xFF);
        bytearr[count++] = (byte) ((utflen  > > > 0) & 0xFF);
        int i=0;
        for (i=0; i< strlen; i++) {
           c = str.charAt(i);
           if (!((c  >= 0x0001) && (c < = 0x007F))) break;
           bytearr[count++] = (byte) c;
        }
        for (;i <  strlen; i++){
            c = str.charAt(i);
            if ((c  >= 0x0001) && (c < = 0x007F)) {
                bytearr[count++] = (byte) c;
            } else if (c  > 0x07FF) {
                bytearr[count++] = (byte) (0xE0 | ((c  > > 12) & 0x0F));
                bytearr[count++] = (byte) (0x80 | ((c  > >  6) & 0x3F));
                bytearr[count++] = (byte) (0x80 | ((c  > >  0) & 0x3F));
            } else {
                bytearr[count++] = (byte) (0xC0 | ((c  > >  6) & 0x1F));
                bytearr[count++] = (byte) (0x80 | ((c  > >  0) & 0x3F));
            }
        }
        out.write(bytearr, 0, utflen+2);
        return utflen + 2;
}

Writes a string to the specified DataOutput using modified UTF-8 encoding in a machine-independent manner.

First, two bytes are written to out as if by the writeShort method giving the number of bytes to follow. This value is the number of bytes actually written out, not the length of the string. Following the length, each character of the string is output, in sequence, using the modified UTF-8 encoding for the character. If no exception is thrown, the counter written is incremented by the total number of bytes written to the output stream. This will be at least two plus the length of str, and at most two plus thrice the length of str.