convert VNI to Unicode vietnamese charaters

Convert.java

/*
javac convert.java
java convert file1.txt file2.txt

 */
import java.io.*;
import java.nio.charset.StandardCharsets;

public class convert {

    public static void main(String[] args) {

        System.out.println("Hello World");
        if (args.length == 2) {
            conFiles(new File(args[0]), new File(args[1]));
            System.out.println("DONE");
        } else {
            System.out.println("command <File1> <file2>");
        }
    }

    private static String convertVni2Unicode(String str) {
        final String[] VNI_char = {"O\u00C2", "o\u00E2", "y\u00F5", "Y\u00D5", "y\u00FB", "Y\u00DB",
            "y\u00F8", "Y\u00D8", "\u00F6\u00EF", "\u00D6\u00CF", "\u00F6\u00F5", "\u00D6\u00D5",
            "\u00F6\u00FB", "\u00D6\u00DB", "\u00F6\u00F8", "\u00D6\u00D8", "\u00F6\u00F9",
            "\u00D6\u00D9", "u\u00FB", "U\u00DB", "u\u00EF", "U\u00CF", "\u00F4\u00EF", "\u00D4\u00CF",
            "\u00F4\u00F5", "\u00D4\u00D5", "\u00F4\u00FB", "\u00D4\u00DB", "\u00F4\u00F8",
            "\u00D4\u00D8", "\u00F4\u00F9", "\u00D4\u00D9", "o\u00E4", "O\u00C4", "o\u00E3", "O\u00C3",
            "o\u00E5", "O\u00C5", "o\u00E0", "O\u00C0", "o\u00E1", "O\u00C1", "o\u00FB", "O\u00DB",
            "o\u00EF", "O\u00CF", "e\u00E4", "E\u00C4", "e\u00E3", "E\u00C3", "e\u00E5", "E\u00C5",
            "e\u00E0", "E\u00C0", "e\u00E1", "E\u00C1", "e\u00F5", "E\u00D5", "e\u00FB", "E\u00DB",
            "e\u00EF", "E\u00CF", "a\u00EB", "A\u00CB", "a\u00FC", "A\u00DC", "a\u00FA", "A\u00DA",
            "a\u00E8", "A\u00C8", "a\u00E9", "A\u00C9", "a\u00E4", "A\u00C4", "a\u00E3", "A\u00C3",
            "a\u00E5", "A\u00C5", "a\u00E0", "A\u00C0", "a\u00E1", "A\u00C1", "a\u00FB", "A\u00DB",
            "a\u00EF", "A\u00CF", "u\u00F5", "U\u00D5", "a\u00EA", "A\u00CA", "y\u00F9", "u\u00F9",
            "u\u00F8", "o\u00F5", "o\u00F9", "o\u00F8", "e\u00E2", "e\u00F9", "e\u00F8", "a\u00F5",
            "a\u00E2", "a\u00F9", "a\u00F8", "Y\u00D9", "U\u00D9", "U\u00D8", "O\u00D5", "O\u00D9",
            "O\u00D8", "E\u00C2", "E\u00D9", "E\u00D8", "A\u00D5", "A\u00C2", "A\u00D9", "A\u00D8"};
        final String[] Unicode_char = {"\u00C6", "\u00E6", "\u1EF9", "\u1EF8", "\u1EF7", "\u1EF6",
            "\u1EF3", "\u1EF2", "\u1EF1", "\u1EF0", "\u1EEF", "\u1EEE", "\u1EED", "\u1EEC", "\u1EEB",
            "\u1EEA", "\u1EE9", "\u1EE8", "\u1EE7", "\u1EE6", "\u1EE5", "\u1EE4", "\u1EE3", "\u1EE2",
            "\u1EE1", "\u1EE0", "\u1EDF", "\u1EDE", "\u1EDD", "\u1EDC", "\u1EDB", "\u1EDA", "\u1ED9",
            "\u1ED8", "\u1ED7", "\u1ED6", "\u1ED5", "\u1ED4", "\u1ED3", "\u1ED2", "\u1ED1", "\u1ED0",
            "\u1ECF", "\u1ECE", "\u1ECD", "\u1ECC", "\u1EC7", "\u1EC6", "\u1EC5", "\u1EC4", "\u1EC3",
            "\u1EC2", "\u1EC1", "\u1EC0", "\u1EBF", "\u1EBE", "\u1EBD", "\u1EBC", "\u1EBB", "\u1EBA",
            "\u1EB9", "\u1EB8", "\u1EB7", "\u1EB6", "\u1EB5", "\u1EB4", "\u1EB3", "\u1EB2", "\u1EB1",
            "\u1EB0", "\u1EAF", "\u1EAE", "\u1EAD", "\u1EAC", "\u1EAB", "\u1EAA", "\u1EA9", "\u1EA8",
            "\u1EA7", "\u1EA6", "\u1EA5", "\u1EA4", "\u1EA3", "\u1EA2", "\u1EA1", "\u1EA0", "\u0169",
            "\u0168", "\u0103", "\u0102", "\u00FD", "\u00FA", "\u00F9", "\u00F5", "\u00F3", "\u00F2",
            "\u00EA", "\u00E9", "\u00E8", "\u00E3", "\u00E2", "\u00E1", "\u00E0", "\u00DD", "\u00DA",
            "\u00D9", "\u00D5", "\u00D3", "\u00D2", "\u00CA", "\u00C9", "\u00C8", "\u00C3", "\u00C2",
            "\u00C1", "\u00C0"};

        // Part 1
        str = str.replace('\u00D1', '\u0110') // DD
                .replace('\u00F1', '\u0111') // dd
                .replace('\u00D3', '\u0128') // I~
                .replace('\u00F3', '\u0129') // i~
                .replace('\u00D2', '\u1ECA') // I.
                .replace('\u00F2', '\u1ECB') // i.
                .replace('\u00C6', '\u1EC8') // I?
                .replace('\u00E6', '\u1EC9') // i?
                .replace('\u00CE', '\u1EF4') // Y.
                .replace('\u00EE', '\u1EF5'); // y.

        // Part 2
        // Transform "O\u00C2" -> "\u00C6" to later transform back to "\u00D4" in Part 3
        str = replaceString(str, VNI_char, Unicode_char);

        // Part 3
        str = str.replace('\u00D4', '\u01A0') // O+
                .replace('\u00F4', '\u01A1') // o+
                .replace('\u00D6', '\u01AF') // U+
                .replace('\u00F6', '\u01B0') // u+
                .replace('\u00C6', '\u00D4') // O^
                .replace('\u00E6', '\u00F4'); // o^

        return str;

    }

    static String replaceString(String text, final String[] pattern, final String[] replace) {
        int startIndex;
        int foundIndex;
        StringBuilder result = new StringBuilder();

        for (int i = 0; i < pattern.length; i++) {
            startIndex = 0;
            // Clear the buffer
            result.setLength(0);

            // Look for a pattern to replace
            while ((foundIndex = text.indexOf(pattern[i], startIndex)) >= 0) {
                result.append(text.substring(startIndex, foundIndex));
                result.append(replace[i]);
                startIndex = foundIndex + pattern[i].length();
            }
            result.append(text.substring(startIndex));
            text = result.toString();
        }
        return text;
    }

    static String replaceString(String text, final String pattern, final String replace) {
        int startIndex = 0;
        int foundIndex;
        StringBuilder result = new StringBuilder();

        // Look for a pattern to replace
        while ((foundIndex = text.indexOf(pattern, startIndex)) >= 0) {
            result.append(text.substring(startIndex, foundIndex));
            result.append(replace);
            startIndex = foundIndex + pattern.length();
        }
        result.append(text.substring(startIndex));

        return result.toString();
    }

    private static void conFiles(File infile, File outfile) {
        /*
		FileInputStream inputStream = null;
		java.util.Scanner sc = null;
		try {
			inputStream = new FileInputStream(infile);
			sc = new java.util.Scanner(inputStream, "UTF-16");
			
			Writer out = new OutputStreamWriter(new FileOutputStream(outfile), "UTF-8");
			
			while (sc.hasNextLine()) {
				String line = sc.nextLine();
				System.out.println(line);
				out.write (line);
				out.write ("\n");
			}
			out.close();
			
			// note that Scanner suppresses exceptions
			if (sc.ioException() != null) {
				throw sc.ioException();
			}
		}catch(Exception ex){
			ex.printStackTrace();
		} finally {
			if (inputStream != null) {
				try{
				inputStream.close();
				}catch(Exception ex){}
			}
			
			if (sc != null) {
				sc.close();
			}
		}
         */

        try {
            
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(infile) , "UTF-16"));
            PrintWriter out2 = new PrintWriter(new OutputStreamWriter(new FileOutputStream(outfile), StandardCharsets.UTF_8));
            
            String line = reader.readLine();
            String lineU16;
            while(line!=null){
                lineU16 = convertVni2Unicode(line);
                out2.println(lineU16);
                line = reader.readLine();
            }
            
            /*
            Reader in = new InputStreamReader(new FileInputStream(infile), "UTF-16");

            
            Writer out = new OutputStreamWriter(new FileOutputStream("~outfile.txt"), "UTF-8");

            char cbuf[] = new char[2048];
            int len;
            while ((len = in.read(cbuf, 0, cbuf.length)) != -1) {
                out.write(cbuf, 0, len);
            }
            out.close();
            in.close();
            */
            out2.close();
            reader.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }
}