function readfile(path)

      local file = io.open(path, "r")

      if file then

        local content = file:read("*a")

        io.close(file)

        return content

      end

      return nil

end

function writefile(path, content, mode)

      mode = mode or "w+b"

      local file = io.open(path, mode)

      if file then

        if file:write(content) == nil then return false end

        io.close(file)

        return true

      else

        return false

      end

end

--文件读写测试

local a = {x=,y=,z=}

local str = json.encode(a)                --将lua表编码为json格式字符串

local path = cc.FileUtils:getInstance():getWritablePath()

    path = path..filename                 --得到可读写文件的路径

    writefile(path,str,r)                 --将数据写入文件

local b = readfile(path)                  --从文件中读取数据

    printf(b)

end

2. 文件操作示例代码
local path = cc.FileUtils:getInstance():getWritablePath()
cc.FileUtils:getInstance():writeToFile({key="value"}, paht.."filename")     --读取数据的方式
print(ret.key) 
lcoal ret = cc.FileUtils:getInstance():getValueMapFromFile(Path.."filename")  --读取数据的方式2
print(str)
local str = cc.FileUtils:getInstance():getStringFromFile(path.."filename")