Txt轉html，識別txt編碼

package org.x3.cloud.file.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;

/**
 * Created By Rock-Ayl on 2020-05-07
 * txt文本工具箱
 */
public class TxtUtils {

    protected static Logger logger = LoggerFactory.getLogger(TxtUtils.class);

    /**
     * txt轉html
     *
     * @param txtPath  源txt位置
     * @param htmlPath 輸出的html位置
     */
    public static boolean txtToHtml(String txtPath, String htmlPath) {
        //初始化成功失敗,缺省失敗
        boolean isSuccess = false;
        //檢測文件編碼
        String encoding = getFileCoding(txtPath);
        //獲取文件
        File file = new File(txtPath);
        //判斷文件是否存在
        if (file.exists() && file.isFile()) {
            try {
                //獲取文件內容
                InputStreamReader read = new InputStreamReader(new FileInputStream(file), encoding);
                //考慮到txt文本的編碼格式
                BufferedReader bufferedReader = new BufferedReader(read);
                //創建html對象
                FileOutputStream fos = new FileOutputStream(new File(htmlPath));
                //考慮到html的編碼
                OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");
                BufferedWriter bw = new BufferedWriter(osw);
                String lineTxt;
                //一行行讀
                while ((lineTxt = bufferedReader.readLine()) != null) {
                    //寫入
                    bw.write("&nbsp&nbsp&nbsp" + lineTxt + "</br>");
                }
                //清空
                bw.close();
                osw.close();
                fos.close();
                read.close();
                //操作成功
                isSuccess = true;
            } catch (IOException e) {
                logger.error("txt轉html出現異常:{}", e);
            }
        }
        return isSuccess;
    }

    /**
     * 判斷txt文本編碼格式方法
     *
     * @param path 文件path
     * @return 文件編碼 eg: UTF-8
     */
    private static String getFileCoding(String path) {
        //獲取文件
        File file = new File(path);
        //默認按照GBK來
        String charset = "GBK";
        //初始化前三個byte
        byte[] first3Bytes = new byte[3];
        try {
            boolean checked = false;
            //讀取文件流
            BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
            bis.mark(0);
            int read = bis.read(first3Bytes, 0, 3);
            if (read == -1) {
                //文件編碼爲 ANSI
                return charset;
            } else if (first3Bytes[0] == (byte) 0xFF
                    && first3Bytes[1] == (byte) 0xFE) {
                //文件編碼爲 Unicode
                charset = "UTF-16LE";
                checked = true;
            } else if (first3Bytes[0] == (byte) 0xFE
                    && first3Bytes[1] == (byte) 0xFF) {
                //文件編碼爲 Unicode big endian
                charset = "UTF-16BE";
                checked = true;
            } else if (first3Bytes[0] == (byte) 0xEF
                    && first3Bytes[1] == (byte) 0xBB
                    && first3Bytes[2] == (byte) 0xBF) {
                //文件編碼爲 UTF-8
                charset = "UTF-8";
                checked = true;
            }
            bis.reset();
            if (!checked) {
                while ((read = bis.read()) != -1) {
                    if (read >= 0xF0)
                        break;
                    // 單獨出現BF以下的，也算是GBK
                    if (0x80 <= read && read <= 0xBF)
                        break;
                    if (0xC0 <= read && read <= 0xDF) {
                        read = bis.read();
                        // 雙字節 (0xC0 - 0xDF)
                        if (0x80 <= read && read <= 0xBF)
                            // (0x80 - 0xBF),也可能在GB編碼內
                            continue;
                        else
                            break;
                    } else if (0xE0 <= read && read <= 0xEF) {
                        // 也有可能出錯，但是機率較小
                        read = bis.read();
                        if (0x80 <= read && read <= 0xBF) {
                            read = bis.read();
                            if (0x80 <= read && read <= 0xBF) {
                                charset = "UTF-8";
                                break;
                            } else
                                break;
                        } else
                            break;
                    }
                }
            }
            bis.close();
        } catch (IOException e) {
            logger.error("txt識別編碼錯誤:{}", e);
            return charset;
        }
        return charset;
    }

}