java io流清空txt文件内容及填充文件内容

File file = new File(this.getClass().getResource("").getPath());
System.out.println(file.getPath());
String path=file.getPath();
String filename="test1.txt";
//path=path.substring(0,path.indexOf("WEB-INF"))+"upload\\Excel"+"\\"+"import.txt";  //服务器专用
      username= DesUtil.encrypt(username);
      password=DesUtil.encrypt(password);
      ip=DesUtil.encrypt(ip);
      DatabaseName=DesUtil.encrypt(DatabaseName);
path=path.substring(0,path.indexOf("target"))+"src\\main\\webapp\\upload\\Excel"+"\\"+"import.txt";
clearInfoForFile(path);
try {
      FileWriter fileWriter =new FileWriter(path, true);
      String info="";
      info=info+ip+"\n"+DatabaseName+"\n"+username+"\n"+password;
      fileWriter.write(info);
      fileWriter.flush();
      fileWriter.close();
}catch (IOException e){

}
InputStream is = new FileInputStream(path);
String line; // 用来保存每行读取的内容
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
line = reader.readLine(); // 读取第一行
int t=0;
if (line==null){

}else {
   t=1;
}
reader.close();
is.close();

//清空文件内容
public  void clearInfoForFile(String fileName) {
   File file =new File(fileName);
   try {
      if(!file.exists()) {
         file.createNewFile();
      }
      FileWriter fileWriter =new FileWriter(file);
      fileWriter.write("");
      fileWriter.flush();
      fileWriter.close();
   } catch (IOException e) {
      e.printStackTrace();
   }
}