cdm/src/main/java/ucar/nc2/iosp/IospHelper.java
static public Object readData(LayoutBB layout, DataType dataType, Object arr) throws java.io.IOException {
    if (showLayoutTypes) System.out.println("***BB LayoutType=" + layout.getClass().getName());

    if (dataType.getPrimitiveClassType() == byte.class || (dataType == DataType.CHAR)) {
      byte[] pa = (byte[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ByteBuffer bb = chunk.getByteBuffer();
        bb.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = bb.get();
      }
      //return (dataType == DataType.CHAR) ? convertByteToChar(pa) : pa;
      if (dataType == DataType.CHAR) return convertByteToChar(pa);
      else return pa;

    } else if (dataType.getPrimitiveClassType() == short.class) {
      short[] pa = (short[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ShortBuffer buff = chunk.getShortBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType.getPrimitiveClassType() == int.class) {
      int[] pa = (int[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        IntBuffer buff = chunk.getIntBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.FLOAT) {
      float[] pa = (float[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        FloatBuffer buff = chunk.getFloatBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.DOUBLE) {
      double[] pa = (double[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        DoubleBuffer buff = chunk.getDoubleBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType.getPrimitiveClassType() == long.class) {
      long[] pa = (long[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        LongBuffer buff = chunk.getLongBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.STRUCTURE) {
      byte[] pa = (byte[]) arr;
      int recsize = layout.getElemSize();
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ByteBuffer bb = chunk.getByteBuffer();
        bb.position(chunk.getSrcElem() * recsize);
        int pos = (int) chunk.getDestElem() * recsize;
        for (int i = 0; i < chunk.getNelems() * recsize; i++)
          pa[pos++] = bb.get();
      }
      return pa;
    }

    throw new IllegalStateException();
  }
static public Object readData(LayoutBB layout, DataType dataType, Object arr) throws java.io.IOException {
    if (showLayoutTypes) System.out.println("***BB LayoutType=" + layout.getClass().getName());

    if (dataType.getPrimitiveClassType() == byte.class || (dataType == DataType.CHAR)) {
      byte[] pa = (byte[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ByteBuffer bb = chunk.getByteBuffer();
        bb.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = bb.get();
      }
      //return (dataType == DataType.CHAR) ? convertByteToChar(pa) : pa;
      if (dataType == DataType.CHAR) return convertByteToChar(pa);
      else return pa;

    } else if (dataType.getPrimitiveClassType() == short.class) {
      short[] pa = (short[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ShortBuffer buff = chunk.getShortBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType.getPrimitiveClassType() == int.class) {
      int[] pa = (int[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        IntBuffer buff = chunk.getIntBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.FLOAT) {
      float[] pa = (float[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        FloatBuffer buff = chunk.getFloatBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.DOUBLE) {
      double[] pa = (double[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        DoubleBuffer buff = chunk.getDoubleBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType.getPrimitiveClassType() == long.class) {
      long[] pa = (long[]) arr;
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        LongBuffer buff = chunk.getLongBuffer();
        buff.position(chunk.getSrcElem());
        int pos = (int) chunk.getDestElem();
        for (int i = 0; i < chunk.getNelems(); i++)
          pa[pos++] = buff.get();
      }
      return pa;

    } else if (dataType == DataType.STRUCTURE) {
      byte[] pa = (byte[]) arr;
      int recsize = layout.getElemSize();
      while (layout.hasNext()) {
        LayoutBB.Chunk chunk = layout.next();
        ByteBuffer bb = chunk.getByteBuffer();
        bb.position(chunk.getSrcElem() * recsize);
        int pos = (int) chunk.getDestElem() * recsize;
        for (int i = 0; i < chunk.getNelems() * recsize; i++)
          pa[pos++] = bb.get();
      }
      return pa;
    }

    throw new IllegalStateException();
  }
Read data subset from ByteBuffer, place in given primitive array.
Reading is controlled by the LayoutBB object.

@param layout   handles skipping around in the file, privide ByteBuffer to read from
@param dataType dataType of the variable
@param arr      primitive array to read data into
@return the primitive array with data read in
@throws java.io.IOException on read error