package com.test;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.URLDecoder;
import java.net.URLEncoder;

public class Transcoding {
 private BytesEncodingDetect encode = new BytesEncodingDetect();
 public Transcoding() {
 }

 /**
  * 編碼轉換
  * @param toCharset 要轉換的編碼
  * @param path 要轉換的文件路徑
  * @return
  * @throws Exception
  */
 public String encoding(String toCharset, String path) throws Exception{
  File srcFile = new File(path);
  int index = encode.detectEncoding(srcFile);
  String charset = BytesEncodingDetect.javaname[index];
  // 編碼相同，無需轉碼
  if (charset.equalsIgnoreCase(toCharset)) {
   return "編碼一樣，無需轉換";
  }

  InputStream in = new FileInputStream(path);

  BufferedReader br = new BufferedReader(
    new InputStreamReader(in, charset));

  StringBuffer sb = new StringBuffer();
  String s1;
  while ((s1=br.readLine())!=null) {
   String s = URLEncoder.encode(s1, toCharset);
   sb.append(s+"/r/n");//一行+回車
  }

  br.close();
  srcFile.delete();//刪除原來文件
  //重新以新編碼寫入文件并返回值
  File newfile = new File(path);//重新建原來的文件
  newfile.createNewFile();
  OutputStream out = new FileOutputStream(newfile);
  OutputStreamWriter  writer = new OutputStreamWriter(out, toCharset);
  BufferedWriter bw = new BufferedWriter(writer);
  bw.write(URLDecoder.decode(sb.toString(), toCharset));
  String result = URLDecoder.decode(sb.toString(), toCharset);
  bw.flush();//刷到文件中
  bw.close();
  return result;
 }

}