xbytebuffer.java

This temp directory is used by the JVM for temporary file storage. The JVM is configured to use thi

    /**
     * Extracts the message bytes from a package.
     * If no package exists, a IllegalStateException will be thrown.
     * @param clearFromBuffer - if true, the package will be removed from the byte buffer
     * @return - returns the actual message bytes (header, size and footer not included).
     */
    public byte[] extractPackage(boolean clearFromBuffer) throws java.io.IOException {
        int psize = countPackages();
        if ( psize == 0 ) throw new java.lang.IllegalStateException("No package exists in XByteBuffer");
        int size = toInt(buf, START_DATA.length);
        byte[] data = new byte[size];
        System.arraycopy(buf,START_DATA.length+4,data,0,size);
        if ( clearFromBuffer ) {
            int totalsize = START_DATA.length + 4 + size + END_DATA.length;
            bufSize = bufSize - totalsize;
            System.arraycopy(buf, totalsize, buf, 0, bufSize);
        }
        java.io.ByteArrayInputStream bin = new java.io.ByteArrayInputStream(data);
        java.util.zip.GZIPInputStream gin = new java.util.zip.GZIPInputStream(bin);
        byte[] tmp = new byte[1024];
        byte[] result = new byte[0];
        int length = gin.read(tmp);
        while ( length > 0 ) {
            byte[] tmpdata = result;
            result = new byte[result.length+length];
            System.arraycopy(tmpdata,0,result,0,tmpdata.length);
            System.arraycopy(tmp,0,result,tmpdata.length,length);
            length = gin.read(tmp);
        }
        gin.close();
        return result;
    }//extractPackage

    /**
     * Convert four bytes to an int
     * @param b - the byte array containing the four bytes
     * @param off - the offset
     * @return the integer value constructed from the four bytes
     * @exception java.lang.ArrayOutOfBoundsException
     */
    public static int toInt(byte[] b,int off){
        return ( ( (int) b[off+3]) & 0xFF) +
            ( ( ( (int) b[off+2]) & 0xFF) << 8) +
            ( ( ( (int) b[off+1]) & 0xFF) << 16) +
            ( ( ( (int) b[off+0]) & 0xFF) << 24);
    }//toInt

    /**
     * Convert eight bytes to a long
     * @param b - the byte array containing the four bytes
     * @param off - the offset
     * @return the long value constructed from the eight bytes
     * @exception java.lang.ArrayOutOfBoundsException
     */
    public static long toLong(byte[] b,int off){
        return ( ( (long) b[off+7]) & 0xFF) +
            ( ( ( (long) b[off+6]) & 0xFF) << 8) +
            ( ( ( (long) b[off+5]) & 0xFF) << 16) +
            ( ( ( (long) b[off+4]) & 0xFF) << 24) +
            ( ( ( (long) b[off+3]) & 0xFF) << 32) +
            ( ( ( (long) b[off+2]) & 0xFF) << 40) +
            ( ( ( (long) b[off+1]) & 0xFF) << 48) +
            ( ( ( (long) b[off+0]) & 0xFF) << 56);
    }//toInt


    /**
     * Converts an integer to four bytes
     * @param n - the integer
     * @return - four bytes in an array
     */
    public static byte[] toBytes(int n) {
        byte[] b = new byte[4];
        b[3] = (byte) (n);
        n >>>= 8;
        b[2] = (byte) (n);
        n >>>= 8;
        b[1] = (byte) (n);
        n >>>= 8;
        b[0] = (byte) (n);
        return b;
    } //toBytes


    /**
     * Converts an long to eight bytes
     * @param n - the long
     * @return - eight bytes in an array
     */
    public static byte[] toBytes(long n) {
        byte[] b = new byte[8];
        b[7] = (byte) (n);
        n >>>= 8;
        b[6] = (byte) (n);
        n >>>= 8;
        b[5] = (byte) (n);
        n >>>= 8;
        b[4] = (byte) (n);
        n >>>= 8;
        b[3] = (byte) (n);
        n >>>= 8;
        b[2] = (byte) (n);
        n >>>= 8;
        b[1] = (byte) (n);
        n >>>= 8;
        b[0] = (byte) (n);
        return b;
    } //toBytes


    /**
     * Similar to a String.IndexOf, but uses pure bytes
     * @param src - the source bytes to be searched
     * @param srcOff - offset on the source buffer
     * @param find - the string to be found within src
     * @return - the index of the first matching byte. -1 if the find array is not found
     */
    public static int firstIndexOf(byte[] src, int srcOff, byte[] find){
        int result = -1;
        if (find.length > src.length) return result;
        if (find.length == 0 || src.length == 0) return result;
        if (srcOff >= src.length ) throw new java.lang.ArrayIndexOutOfBoundsException();
        boolean found = false;
        int srclen = src.length;
        int findlen = find.length;
        byte first = find[0];
        int pos = srcOff;
        while (!found) {
            //find the first byte
            while (pos < srclen){
                if (first == src[pos])
                    break;
                pos++;
            } //while
            if (pos >= srclen)
                return -1;

            //we found the first character
            //match the rest of the bytes - they have to match
            if ( (srclen - pos) < findlen)
                return -1;
            //assume it does exist
            found = true;
            for (int i = 1; ( (i < findlen) && found); i++)
                found = found && (find[i] == src[pos + i]);
            if (found)
                result = pos;
            else if ( (srclen - pos) < findlen)
                return -1; //no more matches possible
            else
                pos++;
        } //while
        return result;
    } //firstIndexOf

    /**
     * Creates a complete data package
     * @param data - the message data to be contained within the package
     * @return - a full package (header,size,data,footer)
     */
    public static byte[] createDataPackage(byte[] indata) throws java.io.IOException  {
        java.io.ByteArrayOutputStream bout = new java.io.ByteArrayOutputStream(indata.length/2);
        java.util.zip.GZIPOutputStream gout = new java.util.zip.GZIPOutputStream(bout);
        gout.write(indata);
        gout.flush();
        gout.close();
        byte[] data = bout.toByteArray();
        byte[] result = new byte[START_DATA.length+4+data.length+END_DATA.length];
        System.arraycopy(START_DATA,0,result,0,START_DATA.length);
        System.arraycopy(toBytes(data.length),0,result,START_DATA.length,4);
        System.arraycopy(data,0,result,START_DATA.length+4,data.length);
        System.arraycopy(END_DATA,0,result,START_DATA.length+4+data.length,END_DATA.length);
        return result;
    }//createDataPackage

    public static void main(String[] args) throws Exception {
       log.info("Before="+Integer.MAX_VALUE);
       byte[] d = toBytes(Integer.MAX_VALUE);
       log.info("After="+toInt(d,0));


       log.info("Before="+Long.MAX_VALUE);
       d = toBytes(Long.MAX_VALUE);
       log.info("After="+toLong(d,0));

       log.info("Before=" + 4564564);
       d = toBytes((long)4564564);
       log.info("After=" + toLong(d, 0));

       byte[] d1 = createDataPackage(new byte[] {1});
       byte[] d2 = createDataPackage(new byte[] {2});
       byte[] d3 = createDataPackage(new byte[] {3});
       byte[] test = new byte[d1.length+d2.length+d3.length+5];
       System.arraycopy(d1,0,test,0,d1.length);
       System.arraycopy(d2,0,test,d1.length,d2.length);
       System.arraycopy(d3,0,test,d2.length+d1.length,d3.length);
       printBuf(d1);
       printBuf(d2);
       printBuf(d3);
       printBuf(test);
       XByteBuffer b = new XByteBuffer();
       b.append(test,0,test.length);
       int s = b.countPackages();
       log.info("Nr of packages="+s);
       while ( s > 0 ) {
           d = b.extractPackage(true);
           System.out.print("Package d1=");
           printBuf(d);
           s--;
       }//while

    }

    public static void printBuf(byte[] b) {
        StringBuffer buf = new StringBuffer();
        for ( int i=0; i<b.length; i++ ) {
            buf.append(b[i] + " ");
        }
        log.info(buf);
    }

}//class