Need help filling in the areas, unsure of how to do the code, JAVA. I've highlited what needs completing. 

/** LineNumberer is the first example program in Chapter 11. It reads a file and prepends each line with a line number. For example, if the following is the input file: Mary had a little lamb whose fleece was white as snow. Every where that Mary went, the lamb was sure to go. Then the following is the output file (ignoring the // comment symbols) */ // /* 1 */ Mary had a little lamb // /* 2 */ whose fleece was white as snow. // /* 3 */ Every where that Mary went, // /* 4 */ the lamb was sure to go. import java.io.File ; import java.io.FileNotFoundException ; import java.io.PrintWriter ; import java.util.Scanner ; public class LineNumberer {  //-----------Start below here. To do: approximate lines of code = 1 // 1. public static void main( ... so that file IO is possible without catching a possible FileNotFoundException  //-----------------End here. Please do not remove this comment. Reminder: no changes outside the todo regions. { File infile = null ; //-----------Start below here. To do: approximate lines of code = 1 // 2. set infile to the file input1 //-----------------End here. Please do not remove this comment. Reminder: no changes outside the todo regions. Scanner scanner = new Scanner(infile) ; PrintWriter pw = new PrintWriter("output1") ; int lineNumber = 1 ; //-----------Start below here. To do: approximate lines of code = 4 // 3-6. Write the while loop that goes through the input file and prints the output file line by line with the commented line numbers. //-----------------End here. Please do not remove this comment. Reminder: no changes outside the todo regions. long length1 = infile.length() ; pw.close() ; scanner.close() ; //This next part is just to show what is in the output file infile = new File("output1") ; scanner = new Scanner(infile) ; while (scanner.hasNextLine()) { System.out.println(scanner.nextLine()) ; } long length2 = infile.length() ; if (length2 <= length1) System.out.println("Error: You have to print to the given output file.") ; } }