java实现文件编码格式的转化

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.util.Vector;

public class AnsiToUtf8
{

public static void main(String[] args) throws UnsupportedEncodingException,
IOException
{

ReadFileName tmp = new ReadFileName();
Vector<String> vec = tmp.FileNameOftype("file\\comments", ".txt");
int size = vec.size();
System.out.println(size);
for (int i = 0; i < size; i++)
{
change(vec.get(i));
System.out.println(vec.get(i) + "  " + i);
}

}

public static void change(String filepath)
throws UnsupportedEncodingException, IOException
{
BufferedReader buf = null;
OutputStreamWriter pw = null;
String str = null;
String allstr = "";

// 用于输入换行符的字节码
byte[] c = new byte[2];
c[0] = 0x0d;
c[1] = 0x0a;
String t = new String(c);

buf = new BufferedReader(new InputStreamReader(new FileInputStream(
filepath), "gb2312"));			//gb2312转成其他的编码

/*	GBK转成其体的编码
buf = new BufferedReader(new InputStreamReader(new FileInputStream(
filepath), "GBK"));*/

while ((str = buf.readLine()) != null)
{
allstr = allstr + str + t;
}

buf.close();

pw = new OutputStreamWriter(new FileOutputStream(filepath), "UTF-8");		//最终要转换成的文件的编码格式是utf-8
pw.write(allstr);
pw.close();
}

}

class ReadFileName
{

// 存储遍历获取的所有文件名
private Vector<String> filelist = new Vector<String>();

// 遍历指定路径下的所有文件
// 以ArrayList存储于filelist中
private void RefreshFileList(String strpath)
{
File dir = new File(strpath);
File[] files = dir.listFiles();

if (files == null)
return;
for (int i = 0; i < files.length; i++)
{
if (files[i].isDirectory())
{
RefreshFileList(files[i].getAbsolutePath());
} else
{
filelist.add(files[i].getAbsolutePath());
}
}
}

//过滤当前目录下的指定后缀名的文件
//返回Vector
public Vector<String> FileNameOftype(String strpath2, String filetype)
{
String strfilename = new String();
Vector<String> filelistofType = new Vector<String>();

//读取指定路径下的所有文件
RefreshFileList(strpath2);

for (int i = 0; i < filelist.size(); i++)
{
strfilename = filelist.get(i).toString();
strfilename = strfilename.substring(strfilename.length() - 4,
strfilename.length());

if (strfilename.equals(filetype))
{
filelistofType.add(filelist.get(i));
}
}
return filelistofType;
}

}