用于存储来自文件输入Java的动态大小块的最佳数据结构

I'm working on a Java program where I'm reading from a file in dynamic, unknown blocks. That is, each block of data will not always be the same size and the size is determined as data is being read. For I/O I'm using a MappedByteBuffer (the file inputs are on the order of MB).I'm working on a Java program where I'm reading