Java Code Examples for java.io.FileInputStream#available()

private static String getRCEncoding(String fileName) {
	try {
		FileInputStream input = new FileInputStream(fileName);
		// read 4K bytes
		int read = 4096;
		if (input.available() < read){
			read = input.available();
		}
		byte[] bytes = new byte[read];
		input.read(bytes);
		input.close();
		String content = new String(bytes);

		if (content.indexOf("code_page(") != -1) { //$NON-NLS-1$
			String code = content.substring(content.indexOf("code_page(")+10); //$NON-NLS-1$
			code = code.substring(0,code.indexOf(")")); //$NON-NLS-1$
			return RTF2JavaEncoding(code);
		}
	} catch(Exception e) {
		return null;
	}
	return null;
}
 

protected Class findClass2(String name) throws ClassNotFoundException {
  print("Fetching the implementation of "+name);
  int old = _recur;
  try {
    FileInputStream fi = new FileInputStream(name+".impl2");
    byte result[] = new byte[fi.available()];
    fi.read(result);

    print("DefineClass1 on "+name);
    _recur++;
    Class clazz = defineClass(name, result, 0, result.length);
    _recur = old;
    print("Returning newly loaded class.");
    return clazz;
  } catch (Exception e) {
    _recur = old;
    print("Not found on disk.");
    // If we caught an exception, either the class was not found or
    // it was unreadable by our process.
    return null;
    //throw new ClassNotFoundException(e.toString());
  }
}
 

/**
 *  Skip toSkip number of bytes and return the remaining bytes of the file.
 */
private static long skipBytes(FileInputStream fis, int toSkip, long space)
        throws IOException {
    long skip = fis.skip(toSkip);
    if (skip != toSkip) {
        throw new RuntimeException("skip() returns " + skip
                                   + " but expected " + toSkip);
    }
    long newSpace = space - toSkip;
    long remaining = newSpace > 0 ? newSpace : 0;
    int avail = fis.available();
    if (avail != remaining) {
        throw new RuntimeException("available() returns " + avail
                                   + " but expected " + remaining);
    }

    System.out.println("Skipped " + skip + " bytes "
                       + " available() returns " + avail);
    return newSpace;
}
 

protected Class findClass2(String name) throws ClassNotFoundException {
  print("Fetching the implementation of "+name);
  int old = _recur;
  try {
    FileInputStream fi = new FileInputStream(name+".impl2");
    byte result[] = new byte[fi.available()];
    fi.read(result);

    print("DefineClass1 on "+name);
    _recur++;
    Class clazz = defineClass(name, result, 0, result.length);
    _recur = old;
    print("Returning newly loaded class.");
    return clazz;
  } catch (Exception e) {
    _recur = old;
    print("Not found on disk.");
    // If we caught an exception, either the class was not found or
    // it was unreadable by our process.
    return null;
    //throw new ClassNotFoundException(e.toString());
  }
}
 

/**
 * 加载本地资源
 *
 * @param response 返回的Response
 * @param path 资源路径
 * @param download 直接下载
 */
public static void loadResource(HttpServletResponse response, String path, boolean download) throws IOException {
    if (Checker.isNotEmpty(path)) {
        File file = new File(path);
        if (download) {
            setResponseFileName(response, file.getName());
        }
        FileInputStream in = new FileInputStream(file);
        ServletOutputStream os = response.getOutputStream();
        byte[] b;
        while (in.available() > 0) {
            b = in.available() > 1024 ? new byte[1024] : new byte[in.available()];
            in.read(b, 0, b.length);
            os.write(b, 0, b.length);
        }
        in.close();
        os.flush();
        os.close();
    } else {
        response.sendRedirect(DefaultValues.NOT_FOUND_PAGE);
    }
}
 

public static String readDataFromFile(String fileName) {
	String res = null;
	try {
		File f = new File(cachePath + fileName);
		if (!f.exists()) {
			return null;
		}
		FileInputStream fin = new FileInputStream(f);
		int length = fin.available();
		if (length > 0) {
			byte[] buffer = new byte[length];
			fin.read(buffer);
			res = new String(buffer, "utf-8");
		}
		fin.close();
	} catch (Exception e) {
		e.printStackTrace();
		LogUtils.PST(e);
	}
	return res;
}
 

protected Class findClass2(String name) throws ClassNotFoundException {
  print("Fetching the implementation of "+name);
  int old = _recur;
  try {
    FileInputStream fi = new FileInputStream(name+".impl2");
    byte result[] = new byte[fi.available()];
    fi.read(result);

    print("DefineClass1 on "+name);
    _recur++;
    Class clazz = defineClass(name, result, 0, result.length);
    _recur = old;
    print("Returning newly loaded class.");
    return clazz;
  } catch (Exception e) {
    _recur = old;
    print("Not found on disk.");
    // If we caught an exception, either the class was not found or
    // it was unreadable by our process.
    return null;
    //throw new ClassNotFoundException(e.toString());
  }
}
 

/**
 * 读取本地文件，传统IO
 * 
 * @param filePath
 *            文件路径
 * @throws FileNotFoundException
 * @throws IOException
 * @return
 */
public static byte[] read(String filePath) throws IOException,
		FileNotFoundException {
	if (filePath == null) {
		return null;
	}
	FileInputStream fis = new FileInputStream(new File(filePath));
	int size = fis.available();
	ByteArrayOutputStream baos = new ByteArrayOutputStream(size);
	byte[] data = null;
	if (size < BUFFER_SIZE) {
		data = new byte[size];
	} else {
		data = new byte[BUFFER_SIZE];
	}
	while (true) {
		int count = fis.read(data);
		if (count == -1) {
			break;
		}
		baos.write(data);
	}
	fis.close();
	return baos.toByteArray();
}
 

private static String getRCEncoding(String fileName) {
	try {
		FileInputStream input = new FileInputStream(fileName);
		// read 4K bytes
		int read = 4096;
		if (input.available() < read) {
			read = input.available();
		}
		byte[] bytes = new byte[read];
		input.read(bytes);
		input.close();
		String content = new String(bytes);

		if (content.indexOf("code_page(") != -1) { //$NON-NLS-1$
			String code = content.substring(content.indexOf("code_page(") + 10); //$NON-NLS-1$
			code = code.substring(0, code.indexOf(")")); //$NON-NLS-1$
			return RTF2JavaEncoding(code);
		}
	} catch (Exception e) {
		return null;
	}
	return null;
}
 

public byte[] loadNVM(String nvmFile) {
	try {
		FileInputStream in = context.openFileInput(nvmFile);
		byte[] nvm = new byte[in.available()];
		in.read(nvm);
		return nvm;
	}
	catch(Exception e) {
		if (e instanceof FileNotFoundException) {
			Log.d(TAG, "Unable to load NVM");
		}
		else {
			Log.d(TAG, "Unable to load NVM", e);
		}
		return null;
	}
}
 

private static PublicKey loadPublicKey(String fileName) throws Exception {
   FileInputStream fis = new FileInputStream(fileName);
   int numBtyes = fis.available();
   byte[] bytes = new byte[numBtyes];
   fis.read(bytes);
   fis.close();

   KeyFactory keyFactory = KeyFactory.getInstance("RSA");
   KeySpec keySpec = new X509EncodedKeySpec(bytes);
   PublicKey keyFromBytes = keyFactory.generatePublic(keySpec);
   return keyFromBytes;
}
 

private Document  getDocument(FileObject fo){
    Document result = null;
    if (documentPooling) {
        result = documentPool().get(fo);
    }
    if (result != null) return result;
    try {
        
        File file = FileUtil.toFile(fo);
        FileInputStream fis = new FileInputStream(file);
        byte buffer[] = new byte[fis.available()];
        result = new org.netbeans.editor.BaseDocument(
                org.netbeans.modules.xml.text.syntax.XMLKit.class, false);
        result.remove(0, result.getLength());
        fis.read(buffer);
        fis.close();
        String str = new String(buffer);
        result.insertString(0,str,null);
        
    } catch (Exception dObjEx) {
        return null;
    }
    if (documentPooling) {
        documentPool().put(fo, result);
    }
    return result;
}
 

@Override
public long open(DataSpec dataSpec) throws ContentDataSourceException {
  try {
    uri = dataSpec.uri;
    assetFileDescriptor = resolver.openAssetFileDescriptor(uri, "r");
    inputStream = new FileInputStream(assetFileDescriptor.getFileDescriptor());
    long skipped = inputStream.skip(dataSpec.position);
    if (skipped < dataSpec.position) {
      // We expect the skip to be satisfied in full. If it isn't then we're probably trying to
      // skip beyond the end of the data.
      throw new EOFException();
    }
    if (dataSpec.length != C.LENGTH_UNSET) {
      bytesRemaining = dataSpec.length;
    } else {
      bytesRemaining = inputStream.available();
      if (bytesRemaining == 0) {
        // FileInputStream.available() returns 0 if the remaining length cannot be determined, or
        // if it's greater than Integer.MAX_VALUE. We don't know the true length in either case,
        // so treat as unbounded.
        bytesRemaining = C.LENGTH_UNSET;
      }
    }
  } catch (IOException e) {
    throw new ContentDataSourceException(e);
  }

  opened = true;
  if (listener != null) {
    listener.onTransferStart(this, dataSpec);
  }

  return bytesRemaining;
}
 

private byte[] loadFromFile(String src) throws IOException {
	FileInputStream in = new FileInputStream(src);
	byte[] b = new byte[in.available()];
	in.read(b);
	in.close();
	return b;
}
 

/**
 * A convenience for {@link #openRead()} that also reads all of the
 * file contents into a byte array which is returned.
 */
public byte[] readFully() throws IOException {
    FileInputStream stream = openRead();
    try {
        int pos = 0;
        int avail = stream.available();
        byte[] data = new byte[avail];
        while (true) {
            int amt = stream.read(data, pos, data.length-pos);
            //Log.i("foo", "Read " + amt + " bytes at " + pos
            //        + " of avail " + data.length);
            if (amt <= 0) {
                //Log.i("foo", "**** FINISHED READING: pos=" + pos
                //        + " len=" + data.length);
                return data;
            }
            pos += amt;
            avail = stream.available();
            if (avail > data.length-pos) {
                byte[] newData = new byte[pos+avail];
                System.arraycopy(data, 0, newData, 0, pos);
                data = newData;
            }
        }
    } finally {
        stream.close();
    }
}
 

public static void main(String[] args) throws IOException {

        Scanner scan = new Scanner(System.in);
        String fileName1 = scan.nextLine();
        String fileName2 = scan.nextLine();
        String fileName3 = scan.nextLine();

        FileInputStream f1 = new FileInputStream(fileName1);
        FileOutputStream f2 = new FileOutputStream(fileName2);
        FileOutputStream f3 = new FileOutputStream(fileName3);

        int fileSize = f1.available();
        int part1Size = fileSize % 2 == 0 ? fileSize / 2 : fileSize / 2 + 1;

        while (f1.available() > 0) {
            byte[] buf1 = new byte [part1Size];
            byte[] buf2 = new byte [fileSize - part1Size];

            f1.read(buf1);
            f1.read(buf2);
            f2.write(buf1);
            f3.write(buf2);
        }
        f1.close ();
        f2.close ();
        f3.close ();
    }
 

/**
 * displays a web page describing the service
 */
public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws IOException, ServletException {
    response.setContentType("text/html");
    ServletOutputStream outStream = response.getOutputStream();
    String fileName = System.getenv("CATALINA_HOME") +
            "/webapps/resourceService/welcome.htm";

    // convert htm file to a byte array
    if (new File(fileName).exists()) {
        FileInputStream fStream = new FileInputStream(fileName);
        byte[] b = new byte[fStream.available()];
        fStream.read(b);
        fStream.close();

        // load the full welcome page if possible
        outStream.write(b);
    }
    else {
        // otherwise load a boring default
        StringBuilder output = new StringBuilder();
        output.append("<html><head><title>YAWL Resource Service</title>")
                .append("</head><body><H3>Welcome to the YAWL Resource Service")
                .append("</H3></body></html>");
        outStream.print(output.toString());
    }
    outStream.flush();
    outStream.close();
}
 

public static void main(String[] args) throws IOException {
    int countSpaces = 0;
    FileInputStream file = new FileInputStream(args[0]);
    int countChars = file.available();
    while (file.available() > 0) {
        if ((byte) file.read() == ' ')
            countSpaces++;
    }
    file.close();
    System.out.printf("%.2f", (double) countSpaces/countChars*100);
}
 

/**
 * This method opens the input and output files and kicks
 * off the processing.
 *
 * @param input Name of the input file
 * @param output Name of the output file
 * @throws Exception Thrown on file read errors
 */
private static void process(String input, String output) throws Exception
{
   FileInputStream is = new FileInputStream(input);
   PrintWriter pw = new PrintWriter(new FileWriter(output));

   byte[] buffer = new byte[is.available()];
   is.read(buffer);
   pw.println(ByteArrayHelper.hexdump(buffer, 0, buffer.length, true, 16, ""));

   is.close();
   pw.flush();
   pw.close();
}
 

public void fillVideoData () {
    Thread thread = new Thread(){
        public void run() {
            String strFile = "/sdcard/00Files/video.dat";
            try {
                File file = new File(strFile);
                FileInputStream input = new FileInputStream(file);
                int nFileSize = input.available();
                int nFilePos = 0;
                int nDataSize = 0;
                int nRC = 0;
                byte[]  byDataInfo = new byte[16];
                byte[]  byDataBuff = new byte[1024000];

                ByteBuffer byBuff = ByteBuffer.wrap(byDataInfo);

                while (nFilePos < nFileSize) {
                    input.read (byDataInfo, 0, 16);
                    nFilePos += 16;

                    nDataSize = byBuff.getInt(0);

                    input.read (byDataBuff, 0, nDataSize);
                    nFilePos += nDataSize;

                    nRC = -1;
                    while (nRC != 0) {
                        nRC = m_Player.SetParam(BasePlayer.QCPLAY_PID_EXT_SOURCE_INFO, 2, byDataInfo);
                    }
                    nRC = -1;
                    while (nRC != 0) {
                        nRC = m_Player.SetParam(BasePlayer.QCPLAY_PID_EXT_SOURCE_DATA, 2, byDataBuff);
                    }
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }
    };
    thread.start();
}