修改版的java导入编码问题(方法)

/**
* 判断文件的编码格式
*
* @param sourceFile
* @return
*/
private static String getFilecharset(File sourceFile) {
String charset = "UTF-8";
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; // 文件编码为 ANSI
} else if (first3Bytes[0] == (byte) 0xFF
&& first3Bytes[1] == (byte) 0xFE) {
charset = "UTF-16LE"; // 文件编码为 Unicode
checked = true;
} else if (first3Bytes[0] == (byte) 0xFE
&& first3Bytes[1] == (byte) 0xFF) {
charset = "UTF-16BE"; // 文件编码为 Unicode big endian
checked = true;
} else if (first3Bytes[0] == 49 && first3Bytes[1] == -60
&& first3Bytes[2] == -29) {
charset = "gb2312"; // 文件编码为 ANSI
checked = true;
} else if (first3Bytes[0] == 49 && first3Bytes[1] == -95
&& first3Bytes[2] == -94) {
charset = "gb2312"; // 文件编码为 ANSI
checked = true;
} else if (first3Bytes[0] == -51 && first3Bytes[1] == -8
&& first3Bytes[2] == -62) {
charset = "gb2312"; // 文件编码为 ANSI
checked = true;
}
bis.reset();
if (!checked) {
int loc = 0;
while ((read = bis.read()) != -1) {
loc++;
if (read >= 0xF0)
break;
if (0x80 <= read && read <= 0xBF) // 单独出现BF以下的，也算是GBK
break;
if (0xC0 <= read && read <= 0xDF) {
read = bis.read();
if (0x80 <= read && read <= 0xBF) // 双字节 (0xC0 - 0xDF)
// (0x80
// - 0xBF),也可能在GB编码内
continue;
else
break;
} else if (0xE0 <= read && read <= 0xEF) {// 也有可能出错，但是几率较小
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;
}