Java binary files writeUTF... explain specifications

I'm studying Java on my own. One of the exercises is the following, however I do not really understand what it is asking to.... any smart java gurus out there that could explain this in more detail and simple words? Thanks

Suppose that you have a binary file that contains numbers whos type is either int or double. You dont know the order of the numbers in the file, but their order is recorded in a string at the begining of the file. The string is composed of the letters i for int, and d for double, in the order of the types of the subsequent numbers. The string is written using the method writeUTF.

For example the string "iddiiddd" indicated th开发者_开发知识库at the file contains eight values, as follows: one integer, followed by two doubles, followed by two integers, followed by three doubles.

Read this binary file and create a new text file of the values written one to a line.

---

writeUTF is a method on DataOutputStream, and you can read in the corresponding data using the readUTF method on DataInputStream. Therefore the steps to reading the binary file are:

• Open a new DataInputStream
• Read in the string using readUTF
• Loop through the characters of the string one at a time.
• If the character is an 'i', use readInt() to read in an int.
• If the character is a 'd', use readDouble() to read in the double.
• Close the DataInputStream.

You will also have to write these out to a text file, for which you can use a FileWriter.