Turn CSVRecord into a List

CSVRecord implements get(int) and size() methods so it’s already pretty
much a list.  However, because it does not implement the List interface,
users cannot take advantage of convenience methods such as subList nor
can they pass records around to methods accepting lists.

Make CSVRecord extend AbstractList so that it implements List interface.

Because AbstractList pravides iterator() implementation, this allows us
to delete said method (alongside toList() method) reducing amount of
code.

Author: mina86

src/changes/changes.xml

@@ -42,6 +42,7 @@
       <action issue="CSV-233" type="add" dev="ggregory" due-to="Gary Gregory">Add predefined CSVFormats for printing MongoDB CSV and TSV.</action>
       <action issue="CSV-208" type="fix" dev="ggregory" due-to="Jurrie Overgoor">Fix escape character for POSTGRESQL_TEXT and POSTGRESQL_CSV formats.</action>
       <action issue="CSV-232" type="fix" dev="ggregory" due-to="Jurrie Overgoor, Gary Gregory">Site link "Source Repository" does not work.</action>
+      <action type="add" dev="mina86" due-to="Michal Nazarewicz">Turn CSVRecord into a List.</action>
     </release>
     <release version="1.6" date="2018-09-22" description="Feature and bug fix release">
       <action issue="CSV-231" type="update" dev="britter">Add more documentation to CSVPrinter.</action>

src/main/java/org/apache/commons/csv/CSVRecord.java

@@ -18,6 +18,7 @@
 package org.apache.commons.csv;
 
 import java.io.Serializable;
+import java.util.AbstractList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -28,7 +29,7 @@
 /**
  * A CSV record parsed from a CSV file.
  */
-public final class CSVRecord implements Serializable, Iterable<String> {
+public final class CSVRecord extends AbstractList<String> implements Serializable {
 
     private static final String[] EMPTY_STRING_ARRAY = new String[0];
 
@@ -75,6 +76,7 @@ public String get(final Enum<?> e) {
      *            a column index (0-based)
      * @return the String at the given index
      */
+    @Override
     public String get(final int i) {
         return values[i];
     }
@@ -197,16 +199,6 @@ public boolean isSet(final String name) {
         return isMapped(name) && mapping.get(name).intValue() < values.length;
     }
 
-    /**
-     * Returns an iterator over the values of this record.
-     *
-     * @return an iterator over the values of this record.
-     */
-    @Override
-    public Iterator<String> iterator() {
-        return toList().iterator();
-    }
-
     /**
      * Puts all values of this record into the given Map.
      *
@@ -232,21 +224,11 @@ <M extends Map<String, String>> M putIn(final M map) {
      *
      * @return the number of values.
      */
+    @Override
     public int size() {
         return values.length;
     }
 
-    /**
-     * Converts the values to a List.
-     *
-     * TODO: Maybe make this public?
-     *
-     * @return a new List
-     */
-    private List<String> toList() {
-        return Arrays.asList(values);
-    }
-
     /**
      * Copies this record into a new Map. The new map is not connect
      *

src/test/java/org/apache/commons/csv/CSVRecordTest.java

@@ -36,7 +36,7 @@
 
 public class CSVRecordTest {
 
-    private enum EnumFixture { UNKNOWN_COLUMN }
+    private enum EnumFixture { first, second, third, UNKNOWN_COLUMN }
 
     private String[] values;
     private CSVRecord record, recordWithHeader;
@@ -67,6 +67,13 @@ public void testGetString() {
         assertEquals(values[2], recordWithHeader.get("third"));
     }
 
+    @Test
+    public void testGetEnum() {
+        assertEquals(values[0], recordWithHeader.get(EnumFixture.first));
+        assertEquals(values[1], recordWithHeader.get(EnumFixture.second));
+        assertEquals(values[2], recordWithHeader.get(EnumFixture.third));
+    }
+
     @Test(expected = IllegalArgumentException.class)
     public void testGetStringInconsistentRecord() {
         header.put("fourth", Integer.valueOf(4));
@@ -193,4 +200,8 @@ private void validateMap(final Map<String, String> map, final boolean allowsNull
         assertEquals(null, map.get("fourth"));
     }
 
+    @Test
+    public void testToString() {
+        assertEquals("CSVRecord [comment=null, mapping=null, recordNumber=0, values=[A, B, C]]", record.toString());
+    }
 }