java中gbk转utf-8

public class GbkToUtf8 {public static void main(String[] args) throws IOException {File filein = new File("G:/test.txt");File fileout = new File("G:/result1.txt");BufferedReader br = new BufferedReader(new FileReader(filein));BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileout, true), "utf-8"));String line = null;StringBuilder content = new StringBuilder();while((line = br.readLine())!=null){String iso = new String(line.getBytes("utf-8"),"iso-8859-1");String utf8 = new String(iso.getBytes("iso-8859-1"),"utf-8");content.append(utf8);}bw.write(content.toString());br.close();bw.close();}}