Replaced read methods with wrappers for opencsv code.

pom.xml

@@ -3,6 +3,10 @@
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
 
     <groupId>edu.unl.cse.csv_io</groupId>
     <artifactId>csv_io</artifactId>
@@ -41,6 +45,11 @@
             <version>4.12</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.opencsv</groupId>
+            <artifactId>opencsv</artifactId>
+            <version>5.0</version>
+        </dependency>
     </dependencies>
 
 </project>

src/main/java/edu/unl/cse/csv_io/CSVReaderWriter.java

@@ -2,18 +2,57 @@
  * CSV Reader/Writer, copyright (c) 2019 Christopher A. Bohn, bohn@unl.edu.
  */
 
-
 package edu.unl.cse.csv_io;
 
+import com.opencsv.CSVReaderHeaderAware;
+import com.opencsv.CSVReaderHeaderAwareBuilder;
+import com.opencsv.exceptions.CsvValidationException;
+
 import java.io.*;
 import java.net.URL;
 import java.util.*;
 
 public class CSVReaderWriter {
-    // this does not (yet) handle data elements that include commas and/or are surrounded by quotation marks
-    private static final String DELIMTER = ",";
-    private static final char BYTE_ORDER_MARK = '\ufeff';
+    @SuppressWarnings("WeakerAccess")
+    public static Set<Map<String, String>> readCSVasSet(String filename) {
+        Set<Map<String, String>> csvSet = null;
+        try (InputStreamReader inputStreamReader = new InputStreamReader(Objects.requireNonNull(
+                CSVReaderWriter.class.getClassLoader().getResourceAsStream("csv/" + filename)))) {
+            csvSet = (Set<Map<String, String>>) parseCSV(inputStreamReader, new HashSet<>());
+        } catch (NullPointerException nullPointerException) {
+            System.err.println("Check spelling of file " + filename + ".");
+            System.exit(1);
+        } catch (IOException ioException) {
+            System.err.println("Error loading " + filename + ".  " + ioException);
+            System.exit(1);
+        } catch (CsvValidationException csvValidationException) {
+            System.err.println("Could not validate a line in " + filename + ".  " + csvValidationException);
+            System.exit(1);
+        }
+        return csvSet;
+    }
 
+    private static Collection<Map<String, String>> parseCSV(InputStreamReader inputStreamReader,
+                                                            Collection<Map<String, String>> destination)
+            throws IOException, CsvValidationException {
+        Map<String, String> line;
+        try {
+            CSVReaderHeaderAware csvReader = new CSVReaderHeaderAwareBuilder(inputStreamReader).build();
+            while ((line = csvReader.readMap()) != null) {
+                destination.add(line);
+            }
+        } catch (NullPointerException ignored) {
+            // CSVReaderHeaderAwareBuilder.build() throws NullPointerException if inputStreamReader is empty
+        }
+        return destination;
+    }
+
+    /* LEGACY METHODS */
+    @SuppressWarnings("WeakerAccess")
+    public static Set<Map<String, String>> readCSV(String filename) {
+        return readCSVasSet(filename);
+    }
+/*
     public static Set<Map<String, String>> readCSV(String filename) {
         Set<Map<String, String>> csvSet = null;
         ClassLoader classLoader = CSVReaderWriter.class.getClassLoader();
@@ -24,6 +63,7 @@ public class CSVReaderWriter {
         }
         return csvSet;
     }
+*/
 
     public static boolean writeCSV(String filename, Set<Map<String, String>> data) {
         boolean wroteFile = true;
@@ -47,6 +87,16 @@ public class CSVReaderWriter {
         return wroteFile;
     }
 
+
+    static Set<Map<String, String>> parseCSV(InputStream inputStream) throws IOException {
+        try {
+            return (Set<Map<String, String>>) parseCSV(new InputStreamReader(inputStream), new HashSet<>());
+        } catch (CsvValidationException csvValidationException) {
+            csvValidationException.printStackTrace();
+            return null;
+        }
+    }
+/*
     static Set<Map<String, String>> parseCSV(InputStream inputStream) throws IOException {
         Set<Map<String, String>> csvSet = new HashSet<>();
         BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
@@ -57,7 +107,8 @@ public class CSVReaderWriter {
             String[] elements = line.split(DELIMTER);
             if (header) {
                 if (elements[0].charAt(0) == BYTE_ORDER_MARK) {
-                    elements[0] = elements[0].substring(1);     // remove text-encoding character sometimes added by Excel
+                    elements[0] = elements[0].substring(1);     // remove text-encoding character sometimes added by
+                    // Excel
                 }
                 fieldNames.addAll(Arrays.asList(elements));
                 header = false;
@@ -72,6 +123,7 @@ public class CSVReaderWriter {
         }
         return csvSet;
     }
+*/
 
     static void placeCSVonStream(Set<Map<String, String>> data, OutputStream outputStream) {
         PrintStream writer = new PrintStream(outputStream);
@@ -103,4 +155,34 @@ public class CSVReaderWriter {
             System.out.println(success ? "Wrote file!" : "Didn't write file");
         }
     */
+/*
+    public static void main(String[] args) {
+        Set<Map<String,String>> students = readCSV("students.csv");
+        for (Map<String,String> student: students) {
+            System.out.println(student.get("Name"));
+        }
+    }
+*//*
+    public static void main(String[] args) {
+        Set<Map<String, String>> courses = readCSV("courses.csv");
+        for (Map<String, String> course : courses) {
+            String foo = course.get("URL");
+            if (foo == null) {
+                foo = "Null object";
+            } else if (foo.equals("")) foo = "Empty String";
+            System.out.println(course.get("CourseID") + " " + course.get("Section") + " " + foo + " " + course.get(
+                    "Prerequisite1"));
+        }
+    }*/
+    public static void main(String[] args) {
+        Set<Map<String, String>> courses = readCSV("empty.csv");
+        for (Map<String, String> course : courses) {
+            String foo = course.get("URL");
+            if (foo == null) {
+                foo = "Null object";
+            } else if (foo.equals("")) foo = "Empty String";
+            System.out.println(course.get("CourseID") + " " + course.get("Section") + " " + foo + " " + course.get(
+                    "Prerequisite1"));
+        }
+    }
 }

src/test/java/edu/unl/cse/csv_io/CSVReaderWriterTest.java

@@ -10,6 +10,7 @@ import java.util.*;
 import static org.junit.Assert.*;
 import static org.hamcrest.CoreMatchers.*;
 
+@SuppressWarnings("unchecked") // pee-yew!
 public class CSVReaderWriterTest {
     private static InputStream inputStream;
     private static OutputStream outputStream;
@@ -62,6 +63,7 @@ public class CSVReaderWriterTest {
             expectedRow.put(headers[i], row[i]);
         }
         // Compare
+       assertNotNull(result);
         Map<String, String> aRow = (Map<String, String>) result.toArray()[0];
         assertEquals(expectedKeys, aRow.keySet());
         assertTrue(result.contains(expectedRow));
@@ -86,12 +88,13 @@ public class CSVReaderWriterTest {
         // Oracle -- Rows
         Map<String, String>[] expectedRows = new Map[2];
         for (int i = 0; i < expectedRows.length; i++) {
-            expectedRows[i] = new HashMap<String, String>();
+            expectedRows[i] = new HashMap<>();
             for (int j = 0; j < headers.length; j++) {
                 expectedRows[i].put(headers[j], rows[i][j]);
             }
         }
         // Compare
+        assertNotNull(result);
         Map<String, String> aRow = (Map<String, String>) result.toArray()[0];
         assertEquals(expectedKeys, aRow.keySet());
         for (Map<String, String> expectedRow : expectedRows) {
@@ -100,7 +103,7 @@ public class CSVReaderWriterTest {
     }
 
     @Test
-    public void testParsingCSVwithOnlyHeaderRow() {
+    public void testParsingCSVWithOnlyHeaderRow() {
         // Input
         String[] headers = {"header1", "header2"};
         String[][] data = {headers};