获取csv文件编码，解决csv读取中文乱码问题

咱们解析csv文件时最经常遇到的问题就是乱码，可能有朋友说了我在解析时直接设定编码类型为GBK，GB2312就可以解决中文乱码，如下

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public static List<List<String>> readTxtOrCsvFile(InputStream input) {     List<List<String>> data = Lists.newArrayList();     if (input == null) {         return data;     }     InputStreamReader read = null;     BufferedReader br = null;     try {         read = new InputStreamReader(input, "GB2312");         br = new BufferedReader(read);         String line;         while ((line = br.readLine()) != null) {             if (StringUtils.isNotBlank(line)) {                 List<String> dd = Arrays.asList(line.split(","));                 List<String> n = new ArrayList<>();                 for (int i = 0; i < dd.size(); i++) {                     String cellData = dd.get(i);                     n.add(buildText(cellData));                 }                 data.add(n);             }         }     } catch (Exception e) {         e.printStackTrace();     } finally {         try {             if (br != null) {                 br.close();             }             if (read != null) {                 read.close();             }             if (input != null) {                 input.close();             }         } catch (Exception e) {             e.printStackTrace();         }     }     return data; }

 这样可以解决部分用户的乱码，我想问下如果我的文件类型为UTF-8呢，这样解析出来的还是有乱码。如何做到完全解决呢。作者本人也遇到这种问题，想了许久，也在网上搜索很久，得到一个解决方案。

解决方案是：自己获取要解析文件编码，然后按照编码进行解析。如何才能获取编码，有如下步骤

1、从流中读取前三个字节到一个byte[3]数组中；
2、通过Integer.toHexString(byte[0] & 0xFF)，将byte[3]数组中的三个byte分别转换成16进制的字符表示；
3、根据对三个byte进行转换后得到的字符串，与UTF-8格式头EFBBBF进行比较即可知道是否UTF-8格式。

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/**  * 读取txt,csv文件  *  * @return  */ public static List<List<String>> readTxtOrCsvFile(InputStream input) {       List<List<String>> data = Lists.newArrayList();     if (input == null) {         return data;     }     InputStreamReader read = null;     BufferedReader br = null;     BufferedInputStream bb = null;     try {         bb = new BufferedInputStream(input);         read = new InputStreamReader(bb, getCharSet(bb));         br = new BufferedReader(read);         String line;         while ((line = br.readLine()) != null) {             if (StringUtils.isNotBlank(line)) {                 List<String> dd = Arrays.asList(line.split(","));                 List<String> n = new ArrayList<>();                 for (int i = 0; i < dd.size(); i++) {                     String cellData = dd.get(i);                     n.add(buildText(cellData));                 }                 data.add(n);             }         }     } catch (Exception e) {         e.printStackTrace();     } finally {         try {             if (br != null) {                 br.close();             }             if (read != null) {                 read.close();             }             if (bb != null) {                 bb.close();             }             if (input != null) {                 input.close();             }         } catch (Exception e) {             e.printStackTrace();         }     }     return data; }     /**  * 获取流对应的编码类型  * @param bb  * @return  * @throws Exception  */ private static String getCharSet(BufferedInputStream bb) throws Exception {       String charSet = null;     byte[] buffer = new byte[3];     //因流读取后再读取可能会缺少内容，此处需要先读，然后再还原     bb.mark(bb.available() + 1);     bb.read(buffer);     bb.reset();     String s = Integer.toHexString(buffer[0] & 0xFF) + Integer.toHexString(buffer[1] & 0xFF) + Integer.toHexString(buffer[2] & 0xFF);     switch (s) {         //GBK,GB2312对应均为d5cbba，统一当成GB2312解析         case "d5cbba":             charSet = "GB2312";             break;         case "efbbbf":             charSet = "UTF-8";             break;         default:             charSet = "GB2312";             break;     }       return charSet; }

 问题圆满解决