Fix for "The header contains duplicate names: " +

tuxBurner · tuxBurner · commit 4b900bd0ced3 · 2014-05-20T11:58:06.000+02:00
Arrays.toString(header) is thrown when the header column is an empty String.
diff --git a/src/main/java/org/apache/commons/csv/CSVParser.java b/src/main/java/org/apache/commons/csv/CSVParser.java
@@ -17,8 +17,6 @@
 
 package org.apache.commons.csv;
 
-import static org.apache.commons.csv.Token.Type.TOKEN;
-
 import java.io.Closeable;
 import java.io.File;
 import java.io.FileReader;
@@ -37,6 +35,8 @@
 import java.util.Map;
 import java.util.NoSuchElementException;
 
+import static org.apache.commons.csv.Token.Type.TOKEN;
+
 /**
  * Parses CSV files according to the specified format.
  *
@@ -377,6 +377,10 @@ private Map<String, Integer> initializeHeader() throws IOException {
             // build the name to index mappings
             if (header != null) {
                 for (int i = 0; i < header.length; i++) {
+                    // skip the header when it is empty
+                    if(header[i] == null || "".equals(header[i])) {
+                      continue;
+                    }
                     if (hdrMap.containsKey(header[i])) {
                         throw new IllegalArgumentException("The header contains duplicate names: " +
                                 Arrays.toString(header));
diff --git a/src/test/java/org/apache/commons/csv/CSVParserTest.java b/src/test/java/org/apache/commons/csv/CSVParserTest.java
@@ -17,16 +17,10 @@
 
 package org.apache.commons.csv;
 
-import static org.apache.commons.csv.Constants.CR;
-import static org.apache.commons.csv.Constants.CRLF;
-import static org.apache.commons.csv.Constants.LF;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import org.apache.commons.io.input.BOMInputStream;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
 
 import java.io.File;
 import java.io.IOException;
@@ -45,10 +39,8 @@
 import java.util.Map;
 import java.util.NoSuchElementException;
 
-import org.apache.commons.io.input.BOMInputStream;
-import org.junit.Assert;
-import org.junit.Ignore;
-import org.junit.Test;
+import static org.apache.commons.csv.Constants.*;
+import static org.junit.Assert.*;
 
 /**
  * CSVParserTest
@@ -497,6 +489,11 @@ public void testDuplicateHeaderEntries() throws Exception {
         CSVParser.parse("a,b,a\n1,2,3\nx,y,z", CSVFormat.DEFAULT.withHeader(new String[]{}));
     }
 
+  @Test()
+  public void testDuplicateHeaderEntriesWithEmptyHeaders() throws Exception {
+    CSVParser.parse("a,,c,d,,\n1,2,3,4,5,6\nx,y,z,v,u,w", CSVFormat.DEFAULT.withHeader(new String[]{}));
+  }
+
     @Test
     public void testGetLine() throws IOException {
         final CSVParser parser = CSVParser.parse(CSV_INPUT, CSVFormat.DEFAULT.withIgnoreSurroundingSpaces(true));
