文件存储 类

public class FileUtil {
    private static String path=Environment.getExternalStorageDirectory().getAbsolutePath()+"/1";

    //存储数据到文件中
    public static void saveFile(String string,String fileName){

       try {
           File file=new File(path,fileName);
           Log.d("log", "saveFile: "+Environment.getExternalStorageDirectory().getAbsolutePath());

           if(file.exists()){
               file.delete();
           }
           file.createNewFile();
           FileOutputStream outputStream=new FileOutputStream(file);
           OutputStreamWriter outputStreamWriter=new OutputStreamWriter(outputStream);
           BufferedWriter bufferedWriter=new BufferedWriter(outputStreamWriter);
           bufferedWriter.write(string);
           bufferedWriter.close();
           outputStream.close();
       }catch (IOException e){
           e.printStackTrace();
       }
    }

    //读取文件内容
    public static String loadFile(String fileName){

        StringBuilder stringBuilder=new StringBuilder();
        try{

        File file=new File(path,fileName);
        if(file.exists()){


        FileInputStream fileInputStream=new FileInputStream(file);
            InputStreamReader inputStreamReader=new InputStreamReader(fileInputStream);
            BufferedReader bufferedReader=new BufferedReader(inputStreamReader);

            String line="";
            while ((line=bufferedReader.readLine())!=null){
                stringBuilder.append(line);
                stringBuilder.append("\n");
            }
            bufferedReader.close();
            fileInputStream.close();
        }
    }catch(IOException e){
            e.printStackTrace();
            return "无文件";
        }

        if(stringBuilder.toString()==""){
            return "无文件";
        }else{
            return stringBuilder.toString();
        }


    }

     //获取目录下的txt文件
    public static String[] getFileNames()
    {
       // List<String> names=new ArrayList<>();
        int i=0;
        String [] names=new String[100];
        File filePath=new File(path);
        File[] files=filePath.listFiles();
       if(files!=null){
           for (File file: files) {
               if(file.isDirectory()){
                   Log.d("log", "getFileNames: ");
               }else{
                   String fileName=file.getName();
                   if(fileName.endsWith(".txt")){
                       Log.d("log", "getFileNames: "+fileName.toString());

                       String s=fileName.substring(0,fileName.lastIndexOf(".")).toString();
                       names[i]=s;
                       i++;
                   }
               }
           }
       }else{
           Log.d("log", "getFileNames: 无文件");
       }
        return names;
    }
}