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POJava read binary file (unsigned long long)
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copied!<p>I want to convert a C code to Java. It reads a binary file:</p> <pre><code>int main(int argc, char**argv) { FILE *fd; unsigned long trameNumber = 0; unsigned long long INDEX; fd = fopen(argv[1],"rb"); if (fd == NULL) { printf("Usage %s [File]\n", argv[0]); exit(1); } fread(&INDEX, sizeof(INDEX),1, fd); printf("INDEX %llx\n",INDEX); trameNumber++; while (fread(&INDEX, sizeof(INDEX),1, fd) != 0) { printf("INDEX %llx\n",INDEX); trameNumber++; } fclose(fd); printf("%lu", trameNumber); return 0; } </code></pre> <p>The output with this code looks like:</p> <pre><code>INDEX 0 INDEX 9800000000000000 INDEX 1801000000000000 INDEX 5001000000000000 INDEX b801000000000000 </code></pre> <p>Here is my Java code. I've tried to do that with <code>BigInteger</code>:</p> <pre><code>public static final int DATA_BYTE_LENGHT = 8; public void readBinary(final String readFilePath) { // A 8 byte buffer = 64 bits ByteBuffer byteBuffer = ByteBuffer.allocate(DATA_BYTE_LENGHT); // Those channels will be used to read/write files FileChannel channelFileInput = null; BigInteger bigIndex = null; try { // File to read final File fileRead = new File(readFilePath); // Channel used to read the file. channelFileInput = new FileInputStream(fileRead).getChannel(); byteBuffer.put(new byte[DATA_BYTE_LENGHT]); byteBuffer.rewind(); // While the file has content while( channelFileInput.read(byteBuffer) != -1 ) { byteBuffer.rewind(); // Big integer positive bigIndex = new BigInteger(1, byteBuffer.array()); byteBuffer.rewind(); System.out.println("INDEX "+bigIndex.toString(16)); // Clear the buffer byteBuffer.put(new byte[DATA_BYTE_LENGHT]); byteBuffer.rewind(); } } catch(FileNotFoundException e) { System.err.println("The file cannot be read: "+e.getMessage()); } catch(Exception e) { System.err.println(e.getMessage()); } finally { // Close file connections IOUtils.closeQuietly(channelFileInput); } } </code></pre> <p>However, <code>read()</code> doesn't seem to read the file correctly. Because the output is:</p> <pre><code>INDEX 0 INDEX 98 INDEX 118 INDEX 150 INDEX 1b8 </code></pre> <p>Could it be an endianess problem? How to solve it?</p> <p>Thanks</p>

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