java.io.BufferedInputStream#skip ( )源码实例Demo

private void testNegative(final int readLimit) throws IOException {
    byte[] bytes = new byte[100];
    for (int i = 0; i < bytes.length; i++) {
        bytes[i] = (byte) i;
    }
    // buffer of 10 bytes
    BufferedInputStream bis =
            new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
    // skip 10 bytes
    bis.skip(10);
    bis.mark(readLimit);   // 1 byte short in buffer size
    // read 30 bytes in total, with internal buffer incread to 20
    bis.read(new byte[20]);
    try {
        bis.reset();
        fail();
    } catch (IOException ex) {
        assertEquals("Resetting to invalid mark", ex.getMessage());
    }
}
 

private void testPositive(final int readLimit) throws IOException {
    byte[] bytes = new byte[100];
    for (int i = 0; i < bytes.length; i++) {
        bytes[i] = (byte) i;
    }
    // buffer of 10 bytes
    BufferedInputStream bis =
            new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
    // skip 10 bytes
    bis.skip(10);
    bis.mark(readLimit);   // buffer size would increase up to readLimit
    // read 30 bytes in total, with internal buffer increased to 20
    bis.read(new byte[20]);
    bis.reset();
    assert (bis.read() == 10);
}
 

private void testNegative(final int readLimit) throws IOException {
    byte[] bytes = new byte[100];
    for (int i=0; i < bytes.length; i++)
        bytes[i] = (byte)i;
    // buffer of 10 bytes
    BufferedInputStream bis =
        new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
    // skip 10 bytes
    bis.skip(10);
    bis.mark(readLimit);   // 1 byte short in buffer size
    // read 30 bytes in total, with internal buffer incread to 20
    bis.read(new byte[20]);
    try {
        bis.reset();
        fail();
    } catch(IOException ex) {
        assertEquals("Resetting to invalid mark", ex.getMessage());
    }
}
 

public static void main(String[] args) throws Exception {
    byte[] buffer = new byte[100];
    ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
    BufferedInputStream bis = new BufferedInputStream(bais, 50);

    byte[] smallBuf = new byte[10];

    bis.read(smallBuf);
    long available = bis.available();
    int request = 50;
    long s = bis.skip(request);
    if (s < available && s < request) {
        System.out.println("Skipped fewer bytes than requested and fewer bytes than available");
        System.out.println("Available: " + available);
        System.out.println("Requested: " + request);
        System.out.println("Skipped: " + s);
    }
}
 

/**
 * Read the header from the Phoenix file.
 *
 * @param stream input stream
 * @return raw header data
 */
private String readHeaderString(BufferedInputStream stream) throws IOException
{
   int bufferSize = 100;
   stream.mark(bufferSize);
   byte[] buffer = new byte[bufferSize];
   stream.read(buffer);
   Charset charset = CharsetHelper.UTF8;
   String header = new String(buffer, charset);
   int prefixIndex = header.indexOf("PPX!!!!|");
   int suffixIndex = header.indexOf("|!!!!XPP");

   if (prefixIndex != 0 || suffixIndex == -1)
   {
      throw new IOException("File format not recognised");
   }

   int skip = suffixIndex + 9;
   stream.reset();
   stream.skip(skip);

   return header.substring(prefixIndex + 8, suffixIndex);
}
 

public byte[] readData(long position, int chunkSize) {
    try {
        if (sending) {
            ips = new FileInputStream(file);
            bufferIps = new BufferedInputStream(ips);
            if (position > 0) {
                long skipped = bufferIps.skip(position);
                LogUtil.i(TAG, "skipped length:" + skipped);
            }
        }

        byte[] data = new byte[chunkSize];
        int readSize = bufferIps.read(data, 0, chunkSize);

        LogUtil.i(TAG,
            "readSize:" + readSize + ",currProgress:" + getProgress() + ",fileLength:" + size);
        addProgress(position + readSize);
        bufferIps.close();
        ips.close();
        bufferIps = null;
        ips = null;
        return data;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}
 

public BOMDetector( BufferedInputStream in ) throws IOException {
  this.in = in;
  in.mark( 16 );
  readBOM();
  in.reset();
  in.skip( bomSize );
}
 

/**
 * Stores the given data for this Document
 */
private int store(InputStream stream) throws IOException {
    final int bigBlockSize = POIFSConstants.BIG_BLOCK_MINIMUM_DOCUMENT_SIZE;
    BufferedInputStream bis = new BufferedInputStream(stream, bigBlockSize+1);
    bis.mark(bigBlockSize);

    // Do we need to store as a mini stream or a full one?
    if(bis.skip(bigBlockSize) < bigBlockSize) {
       _stream = new NPOIFSStream(_filesystem.getMiniStore());
       _block_size = _filesystem.getMiniStore().getBlockStoreBlockSize();
    } else {
       _stream = new NPOIFSStream(_filesystem);
       _block_size = _filesystem.getBlockStoreBlockSize();
    }

    // start from the beginning 
    bis.reset();
    
    // Store it
    OutputStream os = _stream.getOutputStream();
    byte buf[] = new byte[1024];
    int length = 0;
    
    for (int readBytes; (readBytes = bis.read(buf)) != -1; length += readBytes) {
        os.write(buf, 0, readBytes);
    }
    
    // Pad to the end of the block with -1s
    int usedInBlock = length % _block_size;
    if (usedInBlock != 0 && usedInBlock != _block_size) {
        int toBlockEnd = _block_size - usedInBlock;
        byte[] padding = new byte[toBlockEnd];
        Arrays.fill(padding, (byte)0xFF);
        os.write(padding);
    }
    
    // Tidy and return the length
    os.close();
    return length;
}
 

private void testPositive(final int readLimit) throws IOException {
    byte[] bytes = new byte[100];
    for (int i=0; i < bytes.length; i++)
        bytes[i] = (byte)i;
    // buffer of 10 bytes
    BufferedInputStream bis =
        new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
    // skip 10 bytes
    bis.skip(10);
    bis.mark(readLimit);   // buffer size would increase up to readLimit
    // read 30 bytes in total, with internal buffer increased to 20
    bis.read(new byte[20]);
    bis.reset();
    assert(bis.read() == 10);
}
 

@NoWarning("SR_NOT_CHECKED")
void notBug2(BufferedInputStream any, long anyLong) throws IOException {
    while (anyLong > 0) {
        anyLong -= any.skip(anyLong);
    }

}
 

public void openForSending() throws IOException {
	fin = new FileInputStream(sinfile);
	bin = new BufferedInputStream(fin);
	bin.skip(getHeaderLength());
	totalread=getHeaderLength();
	partcount=0;
}
 

public BOMDetector( BufferedInputStream in ) throws IOException {
  this.in = in;
  in.mark( 16 );
  readBOM();
  in.reset();
  in.skip( bomSize );
}
 

/**
 * Send files.
 * */
private boolean writeToSocket(NSPElement nspElem, long start, long end){
    if (interrupt)
        return true;
    currSockPW.write(NETPacket.getCode206(nspElem.getSize(), start, end));
    currSockPW.flush();
    try{
        long count = end - start + 1;       // Meeh. Somehow it works

        InputStream elementIS = context.getContentResolver().openInputStream(nspElem.getUri());
        if (elementIS == null) {
            issueDescription = "NET Unable to obtain InputStream";
            return true;
        }

        BufferedInputStream bis = new BufferedInputStream(elementIS);

        int readPice = 8388608;                     // = 8Mb
        byte[] byteBuf;

        if (bis.skip(start) != start){
            issueDescription = "NET: Unable to skip requested range.";
            nspElem.setStatus(context.getResources().getString(R.string.status_failed_to_upload));
            return true;
        }
        long currentOffset = 0;
        while (currentOffset < count){
            if (interrupt)
                return true;
            if ((currentOffset+readPice) >= count){
                readPice = (int) (count - currentOffset);
            }
            byteBuf = new byte[readPice];

            if (bis.read(byteBuf) != readPice){
                issueDescription = "NET: Reading of nspElem stream suddenly ended.";
                return true;
            }
            currSockOS.write(byteBuf);

            currentOffset += readPice;

            updateProgressBar((int) ((currentOffset+1)/(count/100+1)));

        }
        currSockOS.flush();         // TODO: check if this really needed.
        bis.close();
        resetProgressBar();
    }
    catch (IOException ioe){
        issueDescription = "NET: File transmission failed. Returned: "+ioe.getMessage();
        nspElem.setStatus(context.getResources().getString(R.string.status_failed_to_upload));      // TODO: REDUNDANT?
        return true;
    }
    return false;
}
 

/**
 * NSPContent command handler
 * isItRawRequest - if True, just ask NS what's needed
 *                - if False, send ticket
 * */
private boolean handleNSPContent(PFSProvider pfsElement, boolean isItRawRequest){
    int requestedNcaID;

    if (isItRawRequest) {
        byte[] readByte = readUsb();
        if (readByte == null || readByte.length != 4) {
            issueDescription = "GL Handle 'Content' command: [Read requested ID]";
            return false;
        }
        requestedNcaID = ByteBuffer.wrap(readByte).order(ByteOrder.LITTLE_ENDIAN).getInt();
    }
    else {
        requestedNcaID = pfsElement.getNcaTicketID();
    }

    long realNcaOffset = pfsElement.getNca(requestedNcaID).getNcaOffset()+pfsElement.getBodySize();
    long realNcaSize = pfsElement.getNca(requestedNcaID).getNcaSize();

    long readFrom = 0;

    int readPice = 16384; // 8mb NOTE: consider switching to 1mb 1048576
    byte[] readBuf;

    try{
        BufferedInputStream bufferedInStream = new BufferedInputStream(context.getContentResolver().openInputStream(nspElements.get(0).getUri()));      // TODO: refactor?
        if (bufferedInStream.skip(realNcaOffset) != realNcaOffset) {
            issueDescription = "GL Failed to skip NCA offset";
            return false;
        }
        int updateProgressPeriods = 0;
        while (readFrom < realNcaSize){
            if (readPice > (realNcaSize - readFrom))
                readPice = (int)(realNcaSize - readFrom);    // TODO: Troubles could raise here
            readBuf = new byte[readPice];
            if (bufferedInStream.read(readBuf) != readPice) {
                issueDescription = "GL Failed to read data from file.";
                return false;
            }

            if (writeUsb(readBuf)) {
                issueDescription = "GL Failed to write data into NS.";
                return false;
            }

            readFrom += readPice;
            if (updateProgressPeriods++ % 1024 == 0) // Update progress bar after every 16mb goes to NS
                updateProgressBar((int) ((readFrom+1)/(realNcaSize/100+1)));
        }
        bufferedInStream.close();

        resetProgressBar();
    }
    catch (java.io.IOException ioe){
        issueDescription = "GL Failed to read NCA ID "+requestedNcaID+". IO Exception: "+ioe.getMessage();
        return false;
    }
    return true;
}
 

@ExpectWarning("SR_NOT_CHECKED")
void bug1(BufferedInputStream any, long anyLong) throws IOException {
    any.skip(anyLong);
}
 

@ExpectWarning("SR_NOT_CHECKED")
void bug2(BufferedInputStream any, long anyLong) throws IOException {
    any.skip(anyLong);
}
 

@NoWarning("SR_NOT_CHECKED")
long notBug(BufferedInputStream any, long anyLong) throws IOException {
    return any.skip(anyLong);
}
 

public CopybookRecordReader(FileSplit genericSplit, JobConf job)
    throws IOException {
  try {
    String cblPath = job.get(Const.COPYBOOK_INPUTFORMAT_CBL_HDFS_PATH_CONF);

    if (cblPath == null) {
      if (job != null) {
        MapWork mrwork = Utilities.getMapWork(job);

        if (mrwork == null) {
          System.out.println("When running a client side hive job you have to set \"copybook.inputformat.cbl.hdfs.path\" before executing the query." );
          System.out.println("When running a MR job we can get this from the hive TBLProperties" );
        }
        Map<String, PartitionDesc> map = mrwork.getPathToPartitionInfo();
        
        for (Map.Entry<String, PartitionDesc> pathsAndParts : map.entrySet()) {
          System.out.println("Hey");
          Properties props = pathsAndParts.getValue().getProperties();
          cblPath = props
              .getProperty(Const.COPYBOOK_INPUTFORMAT_CBL_HDFS_PATH_CONF);
          break;
        }
      }
    }

    FileSystem fs = FileSystem.get(job);
    BufferedInputStream inputStream = new BufferedInputStream(
        fs.open(new Path(cblPath)));
    CobolCopybookLoader copybookInt = new CobolCopybookLoader();
    externalRecord = copybookInt
        .loadCopyBook(inputStream, "RR", CopybookLoader.SPLIT_NONE, 0,
            "cp037", Convert.FMT_MAINFRAME, 0, null);

    int fileStructure = Constants.IO_FIXED_LENGTH;

    for (ExternalField field : externalRecord.getRecordFields()) {
      recordByteLength += field.getLen();
    }

    // jump to the point in the split that the first whole record of split
    // starts at
    FileSplit split = (FileSplit) genericSplit;

    start = split.getStart();
    end = start + split.getLength();
    final Path file = split.getPath();

    BufferedInputStream fileIn = new BufferedInputStream(fs.open(split
        .getPath()));

    if (start != 0) {
      pos = start - (start % recordByteLength) + recordByteLength;

      fileIn.skip(pos);
    }

    ret = LineIOProvider.getInstance().getLineReader(
        fileStructure,
        LineIOProvider.getInstance().getLineProvider(fileStructure));

    ret.open(fileIn, externalRecord);
  } catch (Exception e) {
    e.printStackTrace();
  } 

}
 

@Override
public void initialize(InputSplit split, TaskAttemptContext context)
    throws IOException, InterruptedException {

  String cblPath = context.getConfiguration().get(
      Const.COPYBOOK_INPUTFORMAT_CBL_HDFS_PATH_CONF);

  FileSystem fs = FileSystem.get(context.getConfiguration());

  BufferedInputStream inputStream = new BufferedInputStream(fs.open(new Path(
      cblPath)));

  CobolCopybookLoader copybookInt = new CobolCopybookLoader();
  try {
    externalRecord = copybookInt
        .loadCopyBook(inputStream, "RR", CopybookLoader.SPLIT_NONE, 0,
            "cp037", Convert.FMT_MAINFRAME, 0, null);

    int fileStructure = Constants.IO_FIXED_LENGTH;

    for (ExternalField field : externalRecord.getRecordFields()) {
      recordByteLength += field.getLen();
    }

    // jump to the point in the split that the first whole record of split
    // starts at
    FileSplit fileSplit = (FileSplit) split;

    start = fileSplit.getStart();
    end = start + fileSplit.getLength();
    final Path file = fileSplit.getPath();

    BufferedInputStream fileIn = new BufferedInputStream(fs.open(fileSplit
        .getPath()));

    if (start != 0) {
      pos = start - (start % recordByteLength) + recordByteLength;

      fileIn.skip(pos);
    }

    ret = LineIOProvider.getInstance().getLineReader(
        fileStructure,
        LineIOProvider.getInstance().getLineProvider(fileStructure));

    ret.open(fileIn, externalRecord);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}