GBK格式文本轉爲UTF-8格式

/**
 * gbk格式文本轉爲utf-8
 */
public class GBKToUTF8Util {
    private static String path1 = "C:\\Users\\Desktop\\temp1\\";
    private static String path2 = "C:\\Users\\Desktop\\temp2\\";

    public static void main(String[] args) throws IOException {
        BufferedReader reader = null;
        BufferedWriter writer = null;
        try {
            File file1 = new File(path1 + "Test.java");
            File file2 = new File(path2 + "Test.java");
            if (!file2.exists()) {
                file2.createNewFile();
            }
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(file1), Charset.forName("GBK")));
            writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file2), Charset.forName("UTF-8")));
            String str;
            while ((str = reader.readLine()) != null) {
                writer.write(str);
                writer.newLine();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (writer != null) {
                    writer.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * gbk轉utf-8
     *
     * @param gbkStr
     * @return
     */
    public static String getUTF8StringFromGBKString(String gbkStr) {
        try {
            return new String(getUTF8BytesFromGBKString(gbkStr), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static byte[] getUTF8BytesFromGBKString(String gbkStr) {
        int n = gbkStr.length();
        byte[] utfBytes = new byte[3 * n];
        int k = 0;
        for (int i = 0; i < n; i++) {
            int m = gbkStr.charAt(i);
            if (m < 128 && m >= 0) {
                utfBytes[k++] = (byte) m;
                continue;
            }
            utfBytes[k++] = (byte) (0xe0 | (m >> 12));
            utfBytes[k++] = (byte) (0x80 | ((m >> 6) & 0x3f));
            utfBytes[k++] = (byte) (0x80 | (m & 0x3f));
        }
        if (k < utfBytes.length) {
            byte[] tmp = new byte[k];
            System.arraycopy(utfBytes, 0, tmp, 0, k);
            return tmp;
        }
        return utfBytes;
    }
}