从pdf读取字节，写入字符txt，然后以字节形式返回pdf

Question

我想阅读pdf文件，将其写入txt，然后阅读此txt并重新创建pdf文件。

  

PDF - 读取字节 - ＆gt;我 - 写字符 - ＆gt; TXT - 读取字符 - ＆gt; ME - 写字节 - ＆gt;的 PDF

我的目标是重新创建初始PDF。但在这个过程中，最终的PDF被破坏了。我无法打开它。

这是出于学习目的，因此无需工具重新编写。我正在努力做甚么可能吗？

谢谢你，我的代码如下。

public class ByteToChar {

    private static final int BUFFER_LENGTH = 8;
    private static final String BYTE_INPUT_FILE = "mypdf.pdf";
    private static final String CHAR_OUTPUT_FILE = "bytesOut.txt";
    private static final String BYTE_OUTPUT_FILE = "bytesPdf.pdf";


    public static void main(String[] args) throws IOException {
        // Reads pdf's bytes, and writes txt's chars
        byteToChar();

        // Reads previous txt's chars and writes pdf's bytes
        charToByte();
    }

    public static void byteToChar() throws IOException {
        byte[] buffer = new byte[BUFFER_LENGTH];
        try (InputStream in = new BufferedInputStream(new FileInputStream(BYTE_INPUT_FILE));
             FileWriter fileWriter = new FileWriter(CHAR_OUTPUT_FILE)) {
            while (in.read(buffer) != -1) {
                String decoded = new String(buffer, "UTF-8");
                fileWriter.write(decoded.toCharArray());
            }
        }
    }

    public static void charToByte() throws IOException {
        char[] buffer = new char[BUFFER_LENGTH];
        try (BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(CHAR_OUTPUT_FILE), "UTF-8"));
             OutputStream out = new FileOutputStream(BYTE_OUTPUT_FILE)) {
            String line;
            while ((line = in.readLine()) != null) {
                out.write(line.getBytes());
            }
        }
    }

}