Java解决读写本地文件中文乱码的问题

public static String readFile(String fileName) {
    String fileCOntent= "";
    try {
      File f = new File(fileName);
      if (f.isFile() && f.exists()) {
        InputStreamReader read = new InputStreamReader(
            new FileInputStream(f), "gbk");
        BufferedReader reader = new BufferedReader(read);
        String line;
        while ((line = reader.readLine()) != null) {
          fileContent += line+"\n";
        }
        read.close();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    return fileContent;
  }

public static void writeFile(String fileName, String fileContent) {
    try {
      File f = new File(fileName);
      if (!f.exists()) {
        f.createNewFile();
      }
      OutputStreamWriter write = new OutputStreamWriter(
          new FileOutputStream(f), "gbk");
      BufferedWriter writer = new BufferedWriter(write);
      writer.write(fileContent);
      writer.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }