利用Java读取二进制文件实例详解

`-- networkProj
 |-- data
 |-- networkProj.iml
 |-- out
 `-- src

private static void convertFiles() {
 File folder = new File("data"); // data folder
 log("--------- Read little-endian data from bin file ---------");
 if (!folder.exists()) {
  log("folder is not exist!");
  return;
 }
 File outputFolder = new File(folder.getAbsolutePath() + File.separator + "output");
 if (!outputFolder.exists()) {
  boolean newOutput = outputFolder.mkdir();
  log("New output folder " + newOutput);
 }
 File[] files = folder.listFiles();
 if (files != null) {
  log("folder is " + folder.getAbsolutePath());
  for (File f : files) {
   log("\t" + f.getName());
  }
 } else {
  log("Nothing in this folder");
  return;
 }
 for (File currentFile : files) {
  if (!currentFile.isFile()) {
   return;
  }
  String fileName = currentFile.getName();
  fileName = fileName.substring(0, fileName.length() - 4); // delete suffix
  File csvFile = new File(outputFolder.getAbsolutePath() + File.separator + fileName + ".csv");
  if (csvFile.exists()) {
   boolean deRes = csvFile.delete();
   log("Delete old csv: " + deRes);
  }
  byte[] readBytes = new byte[512];
  try {
   boolean newCsv = csvFile.createNewFile();
   log(csvFile.getAbsolutePath() + " " + newCsv);
   FileOutputStream csvFos = new FileOutputStream(csvFile);
   InputStream in = new FileInputStream(currentFile);
   while (in.read(readBytes) != -1) {
    int[] csvData = convertBytesToInts(readBytes);
    for (int d : csvData) {
     csvFos.write(String.valueOf(d).getBytes());
     csvFos.write("\n".getBytes());
    }
   }
   csvFos.flush();
   csvFos.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}
// little-endian; 2 bytes -> 1 int
private static int[] convertBytesToInts(byte[] inputData) {
 int[] rawData = new int[inputData.length / 2];
 int rawIndex = 0;
 for (int i = 0; i < inputData.length; i += 2) {
  int raw = (0xff & inputData[i + 1]) * 256 + (0xff & inputData[i]);
  if (raw >= 32768) {
   raw -= 65536;
  }
  rawData[rawIndex] = raw;
  rawIndex++;
 }
 return rawData;
}
private static void log(String l) {
 System.out.println(l);
}

--------- Read little-endian data from bin file ---------
New output folder true
folder is G:\javaProj\networkProj\data
 data20170215_180621.bin
 output
G:\javaProj\networkProj\data\output\data20170215_180621.csv true