Complex Stream from a File

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In this lab, you will write a program that processes a file using Java stream processing. The file is a text file containing lines of the form:

$271\mathrm{.}72296\mathrm{.}3347\mathrm{.}70231\mathrm{.}61$

That is$,$ each line of the file contains four positive double values. Unfortunately, mistakes in the collection and production of the file are possible: their may be non$-$positive values in the file and the file may contain values that are not numeric.

Step $1$: Create a stream that contain

Use the Files.lines$()$ and Paths.get$()$ to open and read the file to a stream. $$S

Use the Stream.map$()$ method to spit the lines into an array of four strings containing the values.

Use the Stream.filter$()$ method to pass only arrays that only have strings that represent double values $($use the String.matches$()$ method in the filter.

Use the Stream.map$()$ method to convert each array of string into an array of Doubles.

Use the Stream.filter$()$ method to pass only arrays that have all positive values.

Use the Steam.collect$()$ method to collect the arrays into a list. The Collectors.toList$()$ can do this.

After the stream has produced the list, display it$.$ Use Arrays.toString$()$ to display each array:

List contains: $[271\mathrm{.}72,296\mathrm{.}33,47\mathrm{.}7,231\mathrm{.}61][84\mathrm{.}85,208\mathrm{.}83,77\mathrm{.}3,259\mathrm{.}89]...$

Submit your code to pass the first test.

Step $2$: Now write the stream processing code that takes your List and produces an List that contains the integral average of each of the arrays of Double. $$To compute the integral average, the doubles values are truncated to integers $($cast the double values as integers$),$ and divided by the number of values to produce an integer.

Use the $.$stream$()$ method to turn the List into a stream.

Use the Stream.map$()$ method to calculate the average of each array in the stream.

Use the Stream.collect$()$ method to collect the averages into a list.

After the Stream has produces the list, display it $($use System.out.printf$(\%$d$\%$n$",$ a$))$:

List contains the averages

$211157250160...$

Submit your code to pass the second test.

Step $3)$ Write a stream that produces the overall integral average from your List.

Use the stream$()$ method to create the stream from your List.

Use the reduce$()$ method to accumulate the sum of your values. Use the reduce$($T identity, BinaryOperator$)$ overloading.

Use the stream$()$ method to create a second stream from your List and use the Stream.count$()$ method to count the number of elements in the stream.

Divide the sum from $2.$ by the count from $3.$ to get the overall average. Display the overall average using System.out.printf$("\%$d$\%$n$",$ a$)$

Overall average: $198$

Submit your code to pass the third test.

Step $4)$ Now that you have a List of averages and the overall average, write a last stream that produces only the averages fro your List that more than $25\%$ above the overall average. Collect these averages in another List Display this the highest averages using System.out.printf$("\%$d$\%$n$",$ a$)$:

Highest averages: $250$

$294256261...$

Submit your code to pass the fourth test.