Merge pull request #348 from habibasorour/issue_334_comment

Issue 334: 8.3 add comments to code

Author: pearcej

source/ch8_filehandling.ptx

@@ -166,11 +166,11 @@ public class CreateFile {
             Let’s take a look at how we can use Python to understand how read file contents in Java. In order to read files generally you iterate through each line in the file and read the line's content. In Java, you read files in a very similar way, however in Java we will use the <c>Scanner</c> class in order to iterate through the lines.
         </p>
         <p>
-            Consider <xref ref="file-read-python" text="type-global"/> that reads each line of <xref ref="myfile-read" text="type-global"/> and prints it to the console.
+            Consider <xref ref="file-read-python" text="type-global"/> that reads each line of <xref ref="listing-myfile-read" text="type-global"/> and prints it to the console.
         </p>
-        <data xml:id="myfile-read">
+        <data xml:id="listing-myfile-read">
             <title>Data file for reading example</title>
-        <datafile label="myfile-read" filename="myfile.txt" editable="no">
+        <datafile xml:id= "myfile-read" label="myfile-read" filename="myfile.txt" editable="no">
                 <pre>
                     1
                     2
@@ -208,18 +208,18 @@ public class CreateFile {
         <program interactive="activecode"  language="java" add-files= "myfile-read">
             <code>
             import java.io.File;
-            import java.io.FileNotFoundException;
+            import java.io.FileNotFoundException; // This import is necessary to handle the exception if the file is not found
             import java.util.Scanner;
             public class ReadFile {
                 public static void main (String[] args) {
                     String filename = "myfile.txt";
-                    try (Scanner fileReader = new Scanner(new File(filename))) {
-                        while (fileReader.hasNextLine()) {
+                    try (Scanner fileReader = new Scanner(new File(filename))) { // try to open the file and create a Scanner object
+                        while (fileReader.hasNextLine()) { // while there is a next line in the file
                             String data = fileReader.nextLine();
                             System.out.println(data);
                         }
                     } 
-                    catch (FileNotFoundException e) {
+                    catch (FileNotFoundException e) { // and catch the exception if the file is not found
                         System.out.println("Error: The file '" + filename + "' was not found.");
                     }
                 }