Java RandomAccessFile.readFully方法代码示例

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
* Read Product Definition section from raf.
*
* @param raf RandomAccessFile, with pointer at start of section
* @throws java.io.IOException on I/O error
* @throws IllegalArgumentException if not a GRIB-2 record
*/
public Grib2SectionProductDefinition( RandomAccessFile raf) throws IOException {

  long startingPosition = raf.getFilePointer();

  // octets 1-4 (Length of GDS)
  int length = GribNumbers.int4(raf);

 // octet 5
  int section = raf.read();
  if (section != 4)
    throw new IllegalArgumentException("Not a GRIB-2 PDS section");

  // octets 8-9
  raf.skipBytes(2);
  templateNumber = GribNumbers.int2(raf);

  // read in whole GDS as byte[]
  rawData = new byte[length];
  raf.seek(startingPosition);
  raf.readFully(rawData);
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Grib2SectionLocalUse from raf.
 *
 * @param raf RandomAccessFile, with pointer at start od section
 * @throws java.io.IOException on I/O error
 */
public Grib2SectionLocalUse(RandomAccessFile raf) throws IOException {

  // octets 1-4 (Length of GDS)
  int length = GribNumbers.int4(raf);
  int section = raf.read();  // This is section 2

  if (section != 2) {  // no local use section
    length = 0;
    raf.skipBytes(-5);
    rawData = null;
    return;
  } else {
    rawData = new byte[length-5];
    raf.readFully(rawData);
  }
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Grib2SectionIndicator from raf.
 *
 * @param raf RandomAccessFile, with pointer at start (the "GRIB")
 * @throws java.io.IOException on I/O error
 * @throws IllegalArgumentException if not a GRIB-2 record
 */
public Grib2SectionIndicator(RandomAccessFile raf) throws IOException {
	startPos = raf.getFilePointer();
	byte[] b = new byte[4];
	raf.readFully(b);
	// 判断是不是GRIB
	for (int i = 0; i < b.length; i++) {
		if (b[i] != MAGIC[i])
			throw new IllegalArgumentException("Not a GRIB record");
	}

	raf.skipBytes(2);
	discipline = raf.read();
	int edition = raf.read();
	if (edition != 2)
		throw new IllegalArgumentException("Not a GRIB-2 record");

	messageLength = GribNumbers.int8(raf);
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Grib Definition section from raf.
 *
 * @param raf RandomAccessFile, with pointer at start of section
 * @throws java.io.IOException on I/O error
 * @throws IllegalArgumentException if not a GRIB-2 record
 */
public Grib2SectionGridDefinition(RandomAccessFile raf) throws IOException {

  startingPosition = raf.getFilePointer();

  // octets 1-4 (Length of GDS)
  int length = GribNumbers.int4(raf);

 // octet 5
  int section = raf.read();  // This is section 3
  if (section != 3)
    throw new IllegalArgumentException("Not a GRIB-2 GDS section");

  // octets 13-14
  raf.skipBytes(7);
  templateNumber = GribNumbers.uint2(raf);

  // read in whole GDS as byte[]
  rawData = new byte[length];
  raf.seek(startingPosition);
  raf.readFully(rawData);
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Grib Definition section from raf.
 *
 * @param raf RandomAccessFile, with pointer at start of section
 * @throws java.io.IOException      on I/O error
 * @throws IllegalArgumentException if not a GRIB-2 record
 */
public Grib1SectionGridDefinition(RandomAccessFile raf) throws IOException {

  startingPosition = raf.getFilePointer();

  // octets 1-3 (Length of GDS)
  int length = GribNumbers.int3(raf);

  // octet 6
  raf.skipBytes(2);
  gridTemplate = GribNumbers.uint(raf);

  // read in whole GDS as byte[]
  rawData = new byte[length];
  raf.seek(startingPosition);
  raf.readFully(rawData);

  predefinedGridDefinition = -1;
  predefinedGridDefinitionCenter = -1;
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read the bit map array.
 *
 * @param raf read from here
 * @return bit map as array of byte values
 * @throws java.io.IOException on read error
 */
public byte[] getBitmap(RandomAccessFile raf) throws IOException {
  // no bitMap
  if (bitMapIndicator == 255)
    return null;

  // LOOK: bitMapIndicator=254 == previously defined bitmap
  if (bitMapIndicator == 254)
  //  logger.debug("HEY bitMapIndicator=254 previously defined bitmap");

  if (bitMapIndicator != 0) {
    throw new UnsupportedOperationException("Grib2 Bit map section pre-defined (provided by center) = " + bitMapIndicator);
  }

  raf.seek(startingPosition);
  int length = GribNumbers.int4(raf);
  raf.skipBytes(2);

  byte[] data = new byte[length - 6];
  raf.readFully(data);

  return data;

  /* create new bit map when it is first asked for
  boolean[] bitmap = new boolean[numberOfPoints];
  int[] bitmask = {128, 64, 32, 16, 8, 4, 2, 1};
  for (int i = 0; i < bitmap.length; i++) {
    bitmap[i] = (data[i / 8] & bitmask[i % 8]) != 0;
  }
  return bitmap; */
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Grib2SectionIndicator from raf.
 *
 * @param raf RandomAccessFile, with pointer at start (the "GRIB")
 * @throws java.io.IOException on I/O error
 * @throws IllegalArgumentException if not a GRIB-2 record
 */
public Grib1SectionIndicator(RandomAccessFile raf) throws IOException {
  startPos = raf.getFilePointer();
  byte[] b = new byte[4];
  raf.readFully(b);
  for (int i = 0; i < b.length; i++)
    if (b[i] != MAGIC[i])
      throw new IllegalArgumentException("Not a GRIB record");

  messageLength = GribNumbers.uint3(raf);
  int edition = raf.read();
  if (edition != 1)
    throw new IllegalArgumentException("Not a GRIB-1 record");
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
public byte[] getBytes(RandomAccessFile raf) throws IOException {
  raf.seek(startingPosition); // go to the data section
  byte[] data = new byte[msgLength];
  raf.readFully(data);
  return data;
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
public float[] getData41(RandomAccessFile raf, Grib2Drs.Type0 gdrs) throws IOException {
    int nb = gdrs.numberOfBits;
    int D = gdrs.decimalScaleFactor;
    float DD = (float) java.lang.Math.pow((double) 10, (double) D);
    float R = gdrs.referenceValue;
    int E = gdrs.binaryScaleFactor;
    float EE = (float) java.lang.Math.pow( 2.0, (double) E);

    // LOOK: can # datapoints differ from bitmap and data ?
    // dataPoints are number of points encoded, it could be less than the
    // totalNPoints in the grid record if bitMap is used, otherwise equal
    float[] data = new float[totalNPoints];

    // no data to decode, set to reference value
    if (nb == 0) {
      Arrays.fill(data, R);
      return data;
    }

    //  Y * 10**D = R + (X1 + X2) * 2**E
    //   E = binary scale factor
    //   D = decimal scale factor
    //   R = reference value
    //   X1 = 0
    //   X2 = scaled encoded value
    //   data[ i ] = (R + ( X1 + X2) * EE)/DD ;

    byte[] buf = new byte[dataLength - 5];
    raf.readFully(buf);
    InputStream in = new ByteArrayInputStream(buf);
    BufferedImage image = ImageIO.read(in);

    if (nb != image.getColorModel().getPixelSize()){
    	//log.debug("PNG pixel size disagrees with grib number of bits: ",image.getColorModel().getPixelSize(), nb);
    }
      

    DataBuffer db = image.getRaster().getDataBuffer();
    if (bitmap == null) {
      for (int i = 0; i < dataNPoints; i++) {
//        data[i] = (R + imageData[i] * EE) / DD;
        data[i] = (R + db.getElem(i) * EE) / DD;
      }
    } else {
      for (int bitPt = 0, dataPt = 0; bitPt < totalNPoints; bitPt++) {
        if ((bitmap[bitPt / 8] & GribNumbers.bitmask[bitPt % 8]) != 0) {
//          data[i] = (R + imageData[i] * EE) / DD;
          data[bitPt] = (R + db.getElem(dataPt++) * EE) / DD;
        } else {
          data[bitPt] = staticMissingValue;
        }
      }
    }

    return data;
  }
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read the bitmap array when needed
 */
public byte[] getBitmap(RandomAccessFile raf) throws IOException {
  if (startingPosition <= 0) {
    throw new IllegalStateException("Grib1 Bit map has bad starting position");
  }

  raf.seek(startingPosition);

  // octet 1-3 (length of section)
  int length = GribNumbers.uint3(raf);

  // octet 4 unused bits
  raf.read();   // unused

  // octets 5-6
  int bm = raf.readShort();
  if (bm != 0) {
    //logger.warn("Grib1 Bit map section pre-defined (provided by center) bitmap number = {}", bm);
    return null;
  }

  // not sure if length is set correctly when pre-define bitmap is used, so  wait until that to test
  // seeing a -1, bail out
  if (length <= 6 || length > 10e6) {   // look max  ??
    return null;
  }

  // read the bits as integers
  int n = length - 6;
  byte[] data = new byte[n];
  raf.readFully(data);
  return data;

  // create new bit map, octet 4 contains number of unused bits at the end
  /* boolean[] bitmap = new boolean[n * 8 - unused];  // should be
  boolean[] bitmap = new boolean[n * 8];  //

  // fill bit map
  int count = 0;
  int[] bitmask = {128, 64, 32, 16, 8, 4, 2, 1};
  for (int i = 0; i < bitmap.length; i++) {
    bitmap[i] = (data[i / 8] & bitmask[i % 8]) != 0;
    if (bitmap[i]) count++;
  }
  float r = (float) count / 8 / n;
  System.out.printf("bitmap count = %d / %d (%f)%n", count, 8*n,  r);

  return bitmap;  */
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
public byte[] getBytes(RandomAccessFile raf) throws IOException {
  raf.seek(startingPosition); // go to the data section
  byte[] data = new byte[length];
  raf.readFully(data);
  return data;
}
 

import ucar.unidata.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Read Product Definition section from raf.
 *
 * @param raf RandomAccessFile, with pointer at start of section
 * @throws java.io.IOException      on I/O error
 * @throws IllegalArgumentException if not a GRIB-2 record
 */
public Grib1SectionProductDefinition(RandomAccessFile raf) throws IOException {
    int length = GribNumbers.uint3(raf);
    rawData = new byte[length];
    raf.skipBytes(-3);
    raf.readFully(rawData);
}