fixes #15 SKIP_EMPTY_LINES feature for csv parser

csv/README.md

@@ -236,8 +236,8 @@ Jackson supports the following extension or variations:
     * Linefeed character: when generating content, the default linefeed String used is "`\n`" but this may be changed
 * Null value: by default, null values are serialized as empty Strings (""), but any other String value be configured to be used instead (for example, "null", "N/A" etc)
 * Use of first row as a set of column names: as explained earlier, it is possible to configure `CsvSchema` to indicate that the contents of the first (non-comment) document row is taken to mean the set of column names to use
-* Comments
-    * When enabled (via `CsvSchema`, or enabling `JsonParser.Feature.ALLOW_YAML_COMMENTS`), if a row starts with a `#` character, it will be considered a comment and skipped
+* Comments: when enabled (via `CsvSchema`, or enabling `CsvParser.Feature.ALLOW_COMMENTS`), if a row starts with a `#` character, it will be considered a comment and skipped
+* Blank lines: when enabled (using `CsvParser.Feature.SKIP_BLANK_LINES`) rows that are empty or composed only of whitespaces are skipped 
 
 # Limitations
 

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

@@ -1,9 +1,5 @@
 package com.fasterxml.jackson.dataformat.csv;
 
-import java.io.*;
-import java.math.BigDecimal;
-import java.math.BigInteger;
-
 import com.fasterxml.jackson.core.*;
 import com.fasterxml.jackson.core.base.ParserMinimalBase;
 import com.fasterxml.jackson.core.json.DupDetector;
@@ -13,6 +9,12 @@
 import com.fasterxml.jackson.dataformat.csv.impl.CsvIOContext;
 import com.fasterxml.jackson.dataformat.csv.impl.TextBuffer;
 
+import java.io.IOException;
+import java.io.Reader;
+import java.io.Writer;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+
 /**
  * {@link JsonParser} implementation used to expose CSV documents
  * in form that allows other Jackson functionality to deal
@@ -71,11 +73,13 @@ public enum Feature
         IGNORE_TRAILING_UNMAPPABLE(false),
 
         /**
-         * Feature that allows skipping input lines that are completely empty, instead
-         * of being decoded as lines of just a single column with empty String value (or,
+         * Feature that allows skipping input lines that are completely empty or blank (composed only of whitespace),
+         * instead of being decoded as lines of just a single column with an empty/blank String value (or,
          * depending on binding, `null`).
          *<p>
          * Feature is disabled by default.
+         *
+         * @since 2.10
          */
         SKIP_EMPTY_LINES(false),
 
@@ -744,17 +748,18 @@ protected void _readHeaderLine() throws IOException {
      */
     protected JsonToken _handleStartDoc() throws IOException
     {
-        // also, if comments enabled, may need to skip leading ones
-        _reader.skipLeadingComments();
+        // also, if comments enabled, or skip empty lines, may need to skip leading ones
+        _reader.skipLinesWhenNeeded();
+
         // First things first: are we expecting header line? If so, read, process
         if (_schema.usesHeader()) {
             _readHeaderLine();
-            _reader.skipLeadingComments();
+            _reader.skipLinesWhenNeeded();
         }
         // and if we are to skip the first data line, skip it
         if (_schema.skipsFirstDataRow()) {
             _reader.skipLine();
-            _reader.skipLeadingComments();
+            _reader.skipLinesWhenNeeded();
         }
 
         // Only one real complication, actually; empty documents (zero bytes).