BAEL-2236: Reading a CSV file into a array

core-java-io/pom.xml

@@ -154,6 +154,12 @@
             <artifactId>async-http-client</artifactId>
             <version>${async-http-client.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.opencsv</groupId>
+            <artifactId>opencsv</artifactId>
+            <version>${opencsv.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -247,7 +253,7 @@
         <protonpack.version>1.13</protonpack.version>
         <streamex.version>0.6.5</streamex.version>
         <vavr.version>0.9.0</vavr.version>
-
+        <opencsv.version>4.1</opencsv.version>
         <!-- testing -->
         <assertj.version>3.6.1</assertj.version>
         <avaitility.version>1.7.0</avaitility.version>

core-java-io/src/test/java/com/baeldung/csv/ReadCSVInArrayUnitTest.java

@@ -0,0 +1,106 @@
+package com.baeldung.csv;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Scanner;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.opencsv.CSVReader;
+
+public class ReadCSVInArrayUnitTest {
+    public static final String COMMA_DELIMITER = ",";
+    public static final String CSV_FILE = "src/test/resources/book.csv";
+    public static final List<List<String>> EXPECTED_ARRAY = Collections.unmodifiableList(new ArrayList<List<String>>() {
+        {
+            add(new ArrayList<String>() {
+                {
+                    add("Mary Kom");
+                    add("Unbreakable");
+                }
+            });
+            add(new ArrayList<String>() {
+                {
+                    add("Kapil Isapuari");
+                    add("Farishta");
+                }
+            });
+        }
+    });
+
+    @Test
+    public void givenCSVFile_whenBufferedReader_thenContentsAsExpected() throws IOException {
+        List<List<String>> records = new ArrayList<List<String>>();
+        try (BufferedReader br = new BufferedReader(new FileReader(CSV_FILE))) {
+            String line = "";
+            while ((line = br.readLine()) != null) {
+                String[] values = line.split(COMMA_DELIMITER);
+                records.add(Arrays.asList(values));
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
+            Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
+                .toArray(),
+                records.get(i)
+                    .toArray());
+        }
+    }
+
+    @Test
+    public void givenCSVFile_whenScanner_thenContentsAsExpected() throws IOException {
+        List<List<String>> records = new ArrayList<List<String>>();
+        try (Scanner scanner = new Scanner(new File(CSV_FILE));) {
+            while (scanner.hasNextLine()) {
+                records.add(getRecordFromLine(scanner.nextLine()));
+            }
+        } catch (FileNotFoundException e) {
+            e.printStackTrace();
+        }
+        for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
+            Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
+                .toArray(),
+                records.get(i)
+                    .toArray());
+        }
+    }
+
+    private List<String> getRecordFromLine(String line) {
+        List<String> values = new ArrayList<String>();
+        try (Scanner rowScanner = new Scanner(line)) {
+            rowScanner.useDelimiter(COMMA_DELIMITER);
+            while (rowScanner.hasNext()) {
+                values.add(rowScanner.next());
+            }
+        }
+        return values;
+    }
+
+    @Test
+    public void givenCSVFile_whenOpencsv_thenContentsAsExpected() throws IOException {
+        List<List<String>> records = new ArrayList<List<String>>();
+        try (CSVReader csvReader = new CSVReader(new FileReader(CSV_FILE));) {
+            String[] values = null;
+            while ((values = csvReader.readNext()) != null) {
+                records.add(Arrays.asList(values));
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
+            Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
+                .toArray(),
+                records.get(i)
+                    .toArray());
+        }
+    }
+}

core-java-io/src/test/resources/book.csv

@@ -0,0 +1,2 @@
+Mary Kom,Unbreakable
+Kapil Isapuari,Farishta