http://blog.163.com/wf_shunqiziran/blog/static/176307209201258102217810/

最近java讀取文件的時候，經(jīng)常碰到中文亂碼，特研究了一下java 的編碼格式，在java 中

java編碼與txt編碼對應(yīng)

java	txt
unicode	unicode big endian
utf-8	utf-8
utf-16	unicode
gb2312	ANSI

java 讀取txt如果編碼格式不對就會出現(xiàn)亂碼格式，通過下邊方法獲取文本文件編碼格式，然后以指定的編碼讀取文件，就不會出現(xiàn)亂碼(簡單測試了一下，但是也不保證100%)

private static String getFilecharset(File sourceFile) {
 String charset = "GBK";
 byte[] first3Bytes = new byte[3];
 try {
 boolean checked = false;
 BufferedInputStream bis = new BufferedInputStream(new FileInputStream(sourceFile));
   bis.mark(0);
 int read = bis.read(first3Bytes, 0, 3);
 if (read == -1) {
 return charset; //文件編碼為 ANSI
 } else if (first3Bytes[0] == (byte) 0xFF
 && first3Bytes[1] == (byte) 0xFE) {
    charset = "UTF-16LE"; //文件編碼為 Unicode
 checked = true;
 } else if (first3Bytes[0] == (byte) 0xFE
 && first3Bytes[1] == (byte) 0xFF) {
    charset = "UTF-16BE"; //文件編碼為 Unicode big endian
 checked = true;
 } else if (first3Bytes[0] == (byte) 0xEF
 && first3Bytes[1] == (byte) 0xBB
 && first3Bytes[2] == (byte) 0xBF) {
    charset = "UTF-8"; //文件編碼為 UTF-8
 checked = true;
 }
   bis.reset();
 if (!checked) {
 int loc = 0;
 while ((read = bis.read()) != -1) {
     loc++;
 if (read >= 0xF0)
 break;
 if (0x80 <= read && read <= 0xBF) // 單獨出現(xiàn)BF以下的，也算是GBK
 break;
 if (0xC0 <= read && read <= 0xDF) {
      read = bis.read();
 if (0x80 <= read && read <= 0xBF) // 雙字節(jié) (0xC0 - 0xDF)
 // (0x80
 // - 0xBF),也可能在GB編碼內(nèi)
 continue;
 else
 break;
 } else if (0xE0 <= read && read <= 0xEF) {// 也有可能出錯，但是幾率較小
      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 (Exception e) {
   e.printStackTrace();
 }
 return charset;
 }