Fixed #204

csv/src/main/java/com/fasterxml/jackson/dataformat/csv/CsvParser.java

@@ -763,7 +763,6 @@ protected void _readHeaderLine() throws IOException {
  while ((name = _reader.nextString()) != null) {
  // one more thing: always trim names, regardless of config settings
  name = name.trim();
-
  // See if "old" schema defined type; if so, use that type...
  CsvSchema.Column prev = _schema.column(name);
  if (prev != null) {
@@ -776,6 +775,11 @@ protected void _readHeaderLine() throws IOException {
  }
  }
 
+ // [dataformats-text#204]: Drop trailing empty name if so instructed
+ if (CsvParser.Feature.ALLOW_TRAILING_COMMA.enabledIn(_formatFeatures)) {
+ builder.dropLastColumnIfEmpty();
+ }
+
  // Ok: did we get any columns?
  CsvSchema newSchema = builder.build();
  int size = newSchema.size();
@@ -1002,6 +1006,7 @@ protected JsonToken _handleExtraColumn(String value) throws IOException
  if (next == null) { // should end of record or input
  return _handleObjectRowEnd();
  }
+ System.err.println("... yet we did NOT skip");
  }
  }
  // 21-May-2015, tatu: Need to enter recovery mode, to skip remainder of the line

csv/src/main/java/com/fasterxml/jackson/dataformat/csv/CsvSchema.java

@@ -558,6 +558,22 @@ public Builder renameColumn(int index, String newName) {
  return this;
  }
 
+ /**
+ * Helper method called to drop the last collected column name if
+ * it is empty: called if {link CsvParser.Feature#ALLOW_TRAILING_COMMA}
+ * enabled to remove the last entry after being added initially.
+ *
+ * @since 2.11.2
+ */
+ public void dropLastColumnIfEmpty() {
+ final int ix = _columns.size() - 1;
+ if (ix >= 0) {
+ if (_columns.get(ix).getName().isEmpty()) {
+ _columns.remove(ix);
+ }
+ }
+ }
+
  public Builder setColumnType(int index, ColumnType type) {
  _checkIndex(index);
  _columns.set(index, _columns.get(index).withType(type));
@@ -795,7 +811,7 @@ public Builder setNullValue(char[] nvl) {
  _nullValue = nvl;
  return this;
  }
- 
+
  public CsvSchema build()
  {
  Column[] cols = _columns.toArray(new Column[_columns.size()]);
@@ -817,7 +833,7 @@ protected void _checkIndex(int index) {
  /* Configuration, construction
  /**********************************************************************
  */
- 
+
  /**
  * Column definitions, needed for optional header and/or mapping
  * of field names to column positions.

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/TrailingCommaTest.java → csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/TrailingCommaCSVTest.java

@@ -1,5 +1,7 @@
 package com.fasterxml.jackson.dataformat.csv.deser;
 
+import java.util.List;
+
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.MappingIterator;
@@ -8,14 +10,20 @@
 import com.fasterxml.jackson.dataformat.csv.CsvSchema;
 import com.fasterxml.jackson.dataformat.csv.ModuleTestBase;
 
-public class TrailingCommaTest extends ModuleTestBase {
- final CsvMapper MAPPER = mapperForCsv();
-
+public class TrailingCommaCSVTest extends ModuleTestBase
+{
  @JsonPropertyOrder({ "a", "b" })
  static class StringPair {
  public String a, b;
  }
 
+ static class Person {
+ public String name;
+ public int age;
+ } 
+
+ private final CsvMapper MAPPER = mapperForCsv();
+
  public void testDisallowTrailingComma() throws Exception
  {
  final String INPUT = "s,t\nd,e,\n";
@@ -36,4 +44,32 @@ public void testDisallowTrailingComma() throws Exception
 
  it.close();
  }
+
+ // [dataformats-text#204]: should also work for header line
+
+ public void testWithTrailingHeaderComma() throws Exception
+ {
+ final String INPUT = "name,age,\n" + 
+ "Roger,27,\n" + 
+ "Chris,53,\n";
+ final CsvSchema schema = CsvSchema.emptySchema().withHeader();
+
+ MappingIterator<Person> persons = MAPPER
+ .enable(CsvParser.Feature.ALLOW_TRAILING_COMMA)
+ .readerFor(Person.class)
+ .with(schema)
+ .<Person> readValues(INPUT);
+ assertTrue(persons.hasNextValue());
+ Person p = persons.nextValue();
+ assertNotNull(p);
+ assertEquals("Roger", p.name);
+
+ assertTrue(persons.hasNextValue());
+ p = persons.nextValue();
+ assertNotNull(p);
+ assertEquals(53, p.age);
+
+ assertFalse(persons.hasNextValue());
+ persons.close();
+ }
 }

release-notes/CREDITS-2.x

@@ -137,3 +137,7 @@ Francesco Tumanischvili (frantuma@github)
 * Contibuted fix for #201: (yaml) Improve `MINIMIZE_QUOTES` handling to avoid quoting
  for some uses of `#` and `:`
  (2.11.1)
+
+Björn Michael (bjmi@github)
+* Reported #204: `CsvParser.Feature.ALLOW_TRAILING_COMMA` doesn't work with header columns
+ (2.11.2)

release-notes/VERSION-2.x

@@ -8,6 +8,11 @@ Project: jackson-datatypes-text
 === Releases ===
 ------------------------------------------------------------------------
 
+2.11.2 (not yet released)
+
+#204: `CsvParser.Feature.ALLOW_TRAILING_COMMA` doesn't work with header columns
+ (reported by Björn M)
+
 2.11.1 (25-Jun-2020)
 
 #51: (yaml) `YAMLParser._locationFor()` does not use index available from `Mark`