android 文件操作

• 没做容错。只是简单学习

删除 date/date/包名/files文件目录下所有文件

public static void CleanCache(){
       File file = KapApplication.getContext().getFilesDir();
        File[] childrenFiles = file.listFiles();
        for (File childrenFile : childrenFiles){
            if (!childrenFile.isFile()) continue;
            boolean success = childrenFile.delete();
        }
    }

获取 date/date/包名/files文件目录下指定文件

private static String LoadCache(Context context,String fileNameString){
        FileInputStream inputStream;
        BufferedReader reader = null;
        StringBuilder builder = new StringBuilder();
        try{
            inputStream = context.openFileInput(fileNameString);
            reader = new BufferedReader(new InputStreamReader(inputStream));
            String line;
            while((line = reader.readLine()) != null){
                builder.append(line);
            }
        }catch(IOException e){
            e.printStackTrace();
        }finally{
            if(reader != null){
                try{
                    reader.close();
                }catch(IOException e){
                    e.printStackTrace();
                }
            }
        }
        return builder.toString();
    }

保存 文件至date/date/包名/files文件目录下

// 存数据
    private static void SaveCache(Context context, String contentString, String fileNameString) {
        FileOutputStream outputStream;
        BufferedWriter writer = null;
        try {
            outputStream = context.openFileOutput(fileNameString, Context.MODE_PRIVATE);
            writer = new BufferedWriter(new OutputStreamWriter(outputStream));
            writer.write(contentString);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

判断文件存在

    public static boolean FileIsExists(String filePath){
        try {
            File f=new File(filePath);
            if(!f.exists()) return false;
        }
        catch (Exception e) {
            return false;
        }
        return true;
    }