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Deepak-VohraDeepak-Vohra
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BAEL-9289 Update article "Reading a CSV File into an Array" (#18508)
* Create book-2.csv * Create ReadCSVInArrayUnitTest2.java * Update ReadCSVInArrayUnitTest2.java * Update book-2.csv * Update ReadCSVInArrayUnitTest2.java * Create book-3.csv * Update book-3.csv * Update ReadCSVInArrayUnitTest2.java * Delete core-java-modules/core-java-io-conversions/src/test/resources/book-3.csv * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest2.java * Update ReadCSVInArrayUnitTest2.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Delete core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/csv/ReadCSVInArrayUnitTest2.java * Update ReadCSVInArrayUnitTest.java * Rename book-2.csv to book2.csv * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update book2.csv * Update book2.csv * Update ReadCSVInArrayUnitTest.java * Update book2.csv * Update book2.csv * Update book2.csv * Update ReadCSVInArrayUnitTest.java * Update book2.csv * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Create ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVInArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update pom.xml * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Create book3.csv * Create ReadCSVWithCommaInValuesUsingOpenCSVIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Delete core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/csv/ReadCSVWithCommaInValuesUsingOpenCSVIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Create ReadCSVWithCommaInValuesUsingOpenCSVIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Delete core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/csv/ReadCSVWithCommaInValuesUsingOpenCSVIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update book2.csv * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Update ReadCSVWithCommaInValuesIntoArrayUnitTest.java * Create CustomCSVParserUnitTest.java * Update CustomCSVParserUnitTest.java * Update CustomCSVParserUnitTest.java
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6 files changed

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‎core-java-modules/core-java-io-conversions/pom.xml

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@@ -38,7 +38,7 @@
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</build>
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<properties>
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<opencsv.version>5.8</opencsv.version>
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<opencsv.version>5.9</opencsv.version>
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</properties>
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</project>
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</project>

‎core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/csv/CustomCSVParserUnitTest.java

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package com.baeldung.csv;
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import java.io.BufferedReader;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.io.FileReader;
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import java.io.IOException;
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import java.nio.file.Files;
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import java.nio.file.Paths;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.List;
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import org.junit.Assert;
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import org.junit.Test;
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public class CustomCSVParserUnitTest {
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public static final String COMMA_DELIMITER = ",";
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public static final String CSV_FILE = "src/test/resources/book3.csv";
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public static final List<List<String>> EXPECTED_ARRAY = Collections.unmodifiableList(new ArrayList<List<String>>() {
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{
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add(new ArrayList<String>() {
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{
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add("Kom, Mary");
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add("Unbreakable");
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}
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});
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add(new ArrayList<String>() {
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{
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add("Isapuari, Kapil");
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add("Farishta");
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}
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});
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}
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});
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@Test
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public void givenCSVFileWithCommaInValues_whenCustomCSVParser_thenContentsAsExpected() throws IOException {
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List<List<String>> records = new ArrayList<List<String>>();
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try (BufferedReader br = new BufferedReader(new FileReader(CSV_FILE))) {
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String line = "";
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while ((line = br.readLine()) != null) {
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records.add(parseLine(line));
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}
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} catch (Exception e) {
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e.printStackTrace();
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}
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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private static List<String> parseLine(String line) {
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List<String> values = new ArrayList<>();
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boolean inQuotes = false;
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StringBuilder currentValue = new StringBuilder();
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for (char c : line.toCharArray()) {
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if (c == '"') {
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inQuotes = !inQuotes;
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} else if (c == ',' && !inQuotes) {
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values.add(currentValue.toString());
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currentValue = new StringBuilder();
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} else {
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currentValue.append(c);
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}
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}
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values.add(currentValue.toString());
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return values;
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}
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}

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

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@@ -40,6 +40,7 @@ public class ReadCSVInArrayUnitTest {
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}
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});
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@Test
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public void givenCSVFile_whenBufferedReader_thenContentsAsExpected() throws IOException {
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List<List<String>> records = new ArrayList<List<String>>();

‎core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/csv/ReadCSVWithCommaInValuesIntoArrayUnitTest.java

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package com.baeldung.csv;
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import java.io.BufferedReader;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.io.FileReader;
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import java.io.IOException;
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import java.nio.file.Files;
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import java.nio.file.Paths;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.List;
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import java.util.Scanner;
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import java.util.stream.Collectors;
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import java.util.stream.Stream;
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import org.junit.Assert;
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import org.junit.Test;
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import com.opencsv.CSVReader;
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public class ReadCSVWithCommaInValuesIntoArrayUnitTest {
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public static final String COMMA_DELIMITER = "\\|";
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public static final String CSV_FILE = "src/test/resources/book2.csv";
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public static final String CSV_FILE_OpenCSV = "src/test/resources/book3.csv";
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public static final List<List<String>> EXPECTED_ARRAY = Collections.unmodifiableList(new ArrayList<List<String>>() {
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{
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add(new ArrayList<String>() {
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{
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add("\"Kom, Mary\"");
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add("Unbreakable");
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}
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});
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add(new ArrayList<String>() {
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{
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add("\"Isapuari, Kapil\"");
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add("Farishta");
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}
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});
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}
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});
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public static final List<List<String>> EXPECTED_ARRAY_OpenCSV = Collections.unmodifiableList(new ArrayList<List<String>>() {
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{
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add(new ArrayList<String>() {
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{
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add("Kom, Mary");
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add("Unbreakable");
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}
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});
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add(new ArrayList<String>() {
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{
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add("Isapuari, Kapil");
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add("Farishta");
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}
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});
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}
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});
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@Test
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public void givenCSVFileWithCommaInValues_whenOpencsv_thenContentsAsExpected() throws IOException {
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List<List<String>> records = new ArrayList<List<String>>();
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try (CSVReader csvReader = new CSVReader(new FileReader(CSV_FILE_OpenCSV));) {
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String[] values = null;
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while ((values = csvReader.readNext()) != null) {
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records.add(Arrays.asList(values));
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}
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} catch (Exception e) {
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e.printStackTrace();
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}
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for (int i = 0; i < EXPECTED_ARRAY_OpenCSV.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY_OpenCSV.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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@Test
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public void givenCSVFileWithCommaInValues_whenBufferedReader_thenContentsAsExpected() throws IOException {
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List<List<String>> records = new ArrayList<List<String>>();
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try (BufferedReader br = new BufferedReader(new FileReader(CSV_FILE))) {
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String line = "";
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while ((line = br.readLine()) != null) {
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String[] values = line.split(COMMA_DELIMITER);
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records.add(Arrays.asList(values));
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}
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} catch (Exception e) {
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e.printStackTrace();
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}
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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@Test
103+
public void givenCSVFileWithCommaInValues_whenScanner_thenContentsAsExpected() throws IOException {
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List<List<String>> records = new ArrayList<List<String>>();
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try (Scanner scanner = new Scanner(new File(CSV_FILE));) {
106+
while (scanner.hasNextLine()) {
107+
records.add(getRecordFromLine(scanner.nextLine()));
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}
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} catch (FileNotFoundException e) {
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e.printStackTrace();
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}
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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private List<String> getRecordFromLine(String line) {
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List<String> values = new ArrayList<String>();
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try (Scanner rowScanner = new Scanner(line)) {
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rowScanner.useDelimiter(COMMA_DELIMITER);
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while (rowScanner.hasNext()) {
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values.add(rowScanner.next());
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}
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}
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return values;
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}
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@Test
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public void givenCSVFileWithCommaInValues_whenUsingFilesReadAllLinesMethod_thenContentsAsExpected() throws IOException {
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List<List<String>> records = Files.readAllLines(Paths.get(CSV_FILE))
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.stream()
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.map(line -> Arrays.asList(line.split(COMMA_DELIMITER)))
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.collect(Collectors.toList());
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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@Test
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public void givenCSVFileWithCommaInValues_whenUsingFilesNewBufferedReaderMethod_thenContentsAsExpected() throws IOException {
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try (BufferedReader reader = Files.newBufferedReader(Paths.get(CSV_FILE))) {
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List<List<String>> records = reader.lines()
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.map(line -> Arrays.asList(line.split(COMMA_DELIMITER)))
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.collect(Collectors.toList());
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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}
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@Test
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public void givenCSVFileWithCommaInValues_whenUsingFilesLinesMethod_thenContentsAsExpected() throws IOException {
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try (Stream<String> lines = Files.lines(Paths.get(CSV_FILE))) {
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List<List<String>> records = lines.map(line -> Arrays.asList(line.split(COMMA_DELIMITER)))
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.collect(Collectors.toList());
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for (int i = 0; i < EXPECTED_ARRAY.size(); i++) {
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Assert.assertArrayEquals(EXPECTED_ARRAY.get(i)
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.toArray(),
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records.get(i)
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.toArray());
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}
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}
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}
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}

‎core-java-modules/core-java-io-conversions/src/test/resources/book2.csv

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"Kom, Mary"|Unbreakable
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"Isapuari, Kapil"|Farishta

‎core-java-modules/core-java-io-conversions/src/test/resources/book3.csv

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"Kom, Mary",Unbreakable
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"Isapuari, Kapil",Farishta

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