I have an array of type Point, and it is already sorted. I need to create a meth

Question

I have an array of type Point, and it is already sorted.

I need to create a method that does the following:

Furthermore, the second scenario

Do the method in java and post the code here.

Name the output file sortedPoints.txt.

The method writePointsToFile ) in the AbstractSorter class writes the sorted points (in order of increasing index) from the array points to a file with provided name, under certain format that is decided by the sorting order indicated by the value of the instance variable sortByAngle in AbstractSorter. In the output file, adjacent coordinates must have at least one blank space in between. The format is detailed below (a) If sortByAngle false, every line displays the r-and y-coordinates of a single point. This format will allow Mathematica to generate a monotonic polyline

Explanation / Answer

import java.io.*;

import java.util.*;

//Abstract class AbstractSorter definition

abstract class AbstractSorter

{

//To store boolean value true or false

boolean sortByAngle;

//To store points

String points[];

//Method to write points to specified file

abstract void writePointsToFile();

}//End of class

//Class AbstractSorterDemo derived from AbstractSorter class

public class AbstractSorterDemo extends AbstractSorter  

{

//Creates points and assigns value to it

String points1[] = {"-10 0", "-7 -10", "-7 - 10", "-6 3", "-3 -9", "-2 1", "-1 -6", "0 -10", "0 0", "0 8", "3 3", "5 -2", "5 5", "7 3", "8 4"};

String points2[] = {"-7 -10", "-7 -10", "0 - 10", "-3 -9", "-1 -6", "5 -2", "10 5", "10 5", "7 3", "8 4", "5 5", "3 3", "0 0", "-2 1", "0 8", "-6 3", "-10 0"};

//PrintWriter object initialized to null

PrintWriter pw = null;

//File class object declared

File file;

//Overrides method to write onto the file

void writePointsToFile()

{

//Checks if sortByAngle value is false

if(sortByAngle == false)

{

//Assigns points1 data to points of abstract class instance variable

points = points1;

//File class object created to open sortedPoints.txt file for writing

file = new File ("sortedPoints.txt");

//Try block begins

try

{

//PrintWriter object created to write onto the file name specified with file object

pw = new PrintWriter (file);

//Writes heading to the file

pw.printf("Sort by angle is false");

//Loops till end of points

for(int counter = 0; counter < points.length; counter++)

{

//For new line

pw.println();

//Writes data to file

pw.printf("%s", points[counter]);

}//End of for loop

}//End of try block

//Catch to handle file not found exception

catch (FileNotFoundException e)

{

e.printStackTrace();

}//End of catch

//Close printWriter

pw.close();

}//End of if

//Otherwise sortByAngle value is true

else

{

//Assigns points2 data to points of abstract class instance variable

points = points2;

//File class object created to open sortedPoints.txt file for writing

file = new File ("sortedPoints.txt");

//Try block begins

try

{

//PrintWriter object created to write onto the file name specified with file object

pw = new PrintWriter (file);

//Writes heading to the file

pw.printf("Sort by angle is true");

//For new line

pw.println();

//Writes the zero position value to the file

pw.printf("%s", points[0]);

//Loops till end of points

for(int counter = 1; counter < points.length; counter++)

{

//For new line

pw.println();

//Writes data to file

pw.printf("%s %s %s", points[counter], points[0], points[counter]);

}//End of for loop

}//End of try block

//Catch to handle file not found exception

catch (FileNotFoundException e)

{

e.printStackTrace();

}//End of catch

//Close printWriter

pw.close();

}//End of else

}//End of class

//main method definition

public static void main(String[] args)

{

//To store user choice

int ch;

//Scanner class object created

Scanner sc = new Scanner(System.in);

//AbstractSorterDemo class object created

AbstractSorterDemo asd = new AbstractSorterDemo();

//Displays the menu

System.out.println("1: Sort by angle");

System.out.println("2: Do not sort by angle");

//Accepts user choice

System.out.println(" Enter your choice: ");

ch = sc.nextInt();

//Checks if user choice is one

if(ch == 1)

//Set the sortByAngle value to true

asd.sortByAngle = true;

//Checks if user choice is two

else if(ch == 2)

//Set the sortByAngle value to false

asd.sortByAngle = false;

//Otherwise

else

{

System.out.println(" Error: Wrong choice ");

System.exit(0);

}//End of else

//Calls the method to write data to file

asd.writePointsToFile();

}//End of main method

}//End of class AbstractSorterDemo

Sample Run 1:

1: Sort by angle
2: Do not sort by angle

Enter your choice: 3

Error: Wrong choice

Sample Run 2:

1: Sort by angle
2: Do not sort by angle

Enter your choice: 1

File sortedPoints.txt contents

Sort by angle is true
-7 -10
-7 -10 -7 -10 -7 -10
0 - 10 -7 -10 0 - 10
-3 -9 -7 -10 -3 -9
-1 -6 -7 -10 -1 -6
5 -2 -7 -10 5 -2
10 5 -7 -10 10 5
10 5 -7 -10 10 5
7 3 -7 -10 7 3
8 4 -7 -10 8 4
5 5 -7 -10 5 5
3 3 -7 -10 3 3
0 0 -7 -10 0 0
-2 1 -7 -10 -2 1
0 8 -7 -10 0 8
-6 3 -7 -10 -6 3
-10 0 -7 -10 -10 0

Sample Run 3:

1: Sort by angle
2: Do not sort by angle

Enter your choice: 23

File sortedPoints.txt contents

Sort by angle is false
-10 0
-7 -10
-7 - 10
-6 3
-3 -9
-2 1
-1 -6
0 -10
0 0
0 8
3 3
5 -2
5 5
7 3
8 4

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