// 例 5.4.5 GbToBig5.java
import java.io.*;
import java.util.*;
public class GbToBig5
{
	static int iCharNum=0;  // 用來統計讀取的字符個數
	static String readInput(String strInFile) 
	{
		StringBuffer buffer = new StringBuffer();
		try 
		{
			FileInputStream fis = new FileInputStream(strInFile);
            // 以指定的編碼來創建字節流到字符流的轉換流
			InputStreamReader isr = new InputStreamReader(fis, "GB2312");
			Reader in = new BufferedReader(isr);
			int ch;
			while ((ch = in.read()) > -1) 
			{
				iCharNum += 1;   // 統計讀取了多少字符
				buffer.append((char)ch);
			}
			in.close();
			return buffer.toString(); // 將讀取的字符串對象返回
		}catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}
	static void writeOutput(String str, String strOutFile)
	{
		try 
		{
			FileOutputStream fos = new FileOutputStream(strOutFile);
            // 以指定的編碼來創建字符流到字節流的轉換流

			Writer out = new OutputStreamWriter(fos, "Big5");
			out.write(str);  // 將字符串的內容以指定的編碼寫入目標文件
			out.close();
		}catch (IOException e) {
			e.printStackTrace();
			e.printStackTrace();
		}
	}
	public static void main(String[] args) 
	{
		System.out.println("Input GB2312 file, Output Big5 file.");
		if (args.length!=2) 
		{
			System.err.println("Usage: java GbToBig5 gbfile big5file");
			System.exit(1);
		}
		String inputString = readInput(args[0]);
		writeOutput(inputString,args[1]);
		System.out.println("Number of Characters in file: "+iCharNum+".");
	}
}