前言
此文主要给大伙介绍了关于Java读取二进制文件的相关内容,分享出来供大家参考学习,下面话不多说了,来一起看看详细的介绍吧。
读Hex写CSV
data目录下有little-endian bin文件,2个字节代表一个数字。
bin存储的数据格式可自己定义。相同的方法可以直接应用到Android中。
`-- networkProj
|-- data
|-- networkProj.iml
|-- out
`-- src
实现方法
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);
}
控制台输出
--------- 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
总结
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本文来源:http://rustfisher.github.io/2017/02/16/Java_note/Java_Read_Hex_write_csv/