十六进制转换成二进制

长串16进制数据字符串转换二级制

public static void main(String[] args) throws Exception {
    
    
        //  System.out.println(readTxt().replaceAll(" ", ""));
        String str = readTxt();
        int length = str.length() / 2;
        List list = new ArrayList();
        if (length * 2 < str.length()) {
    
    
            length++;
        }
        String[] strs = new String[length];
        int j = 0;
        for (int i = 0; i < str.length(); i++) {
    
    
            if (i % 2 == 0) {
    
    
                strs[j] = "" + str.charAt(i);
            } else {
    
    
                strs[j] = strs[j] + "" + str.charAt(i);
                j++;
            }
        }
        list.addAll(Arrays.asList(strs));
        OutputStream outputStream = new FileOutputStream(new File("d:/123.txt"));
        for (int i = 0; i < list.size(); i++) {
    
    
            int ii = Integer.valueOf(list.get(i).toString(), 16);//十六进制转换成十进制
            String bin = Integer.toBinaryString(ii);//十进制转换成二进制
            bin += " " + bin + " " + bin + "\n";//重复两遍数据
            byte[] bytes = bin.getBytes();
            for (int k = 0; k < bytes.length; k++) {
    
    
                outputStream.write(bytes[k]);
            }
        }
        outputStream.close();

    }
     private static String readTxt() throws Exception {
    
    
        Reader inputStream = new FileReader("d:/image.txt");
        BufferedReader reader = new BufferedReader(inputStream);
        String str = "";
        StringBuilder builder = new StringBuilder();

        while ((str = reader.readLine()) != null) {
    
    
            builder.append(str);
        }
        return builder.toString();
    }

image.txt中存放十六进制数据，先将十六进制数据读取成字符串，后将字符串以每两个隔开构成16进制数，后将十六进制数转换成十进制，再将十进制转换成二进制数据，这样就完成了十六进制转换成二进制。
因需要，后续将二进制数据重复两遍构成一行数据进行输出到txt文件中