Added basic csv parser

src/main/java/net/fortuna/ical4j/extensions/data/CalendarCSVParser.java

@@ -0,0 +1,46 @@
+package net.fortuna.ical4j.extensions.data;
+
+import net.fortuna.ical4j.data.CalendarParser;
+import net.fortuna.ical4j.data.ContentHandler;
+import net.fortuna.ical4j.data.ParserException;
+
+import java.io.*;
+
+/**
+ * Support parsing CSV files to produce {@link net.fortuna.ical4j.model.Calendar} objects.
+ */
+public class CalendarCSVParser implements CalendarParser {
+
+    private final String componentName;
+
+    public CalendarCSVParser(String componentName) {
+        this.componentName = componentName;
+    }
+
+    @Override
+    public void parse(InputStream inputStream, ContentHandler contentHandler) throws IOException, ParserException {
+        parse(new InputStreamReader(inputStream), contentHandler);
+    }
+
+    @Override
+    public void parse(Reader reader, ContentHandler contentHandler) throws IOException, ParserException {
+        try (BufferedReader in = new BufferedReader(reader)) {
+            contentHandler.startCalendar();
+
+            String[] properties = in.readLine().split(",");
+            String line;
+            while ((line = in.readLine()) != null) {
+                contentHandler.startComponent(componentName);
+                String[] values = line.split(",");
+                for (int i = 0; i < properties.length; i++) {
+                    contentHandler.startProperty(properties[i]);
+                    contentHandler.propertyValue(values[i]);
+                    contentHandler.endProperty(properties[i]);
+                }
+                contentHandler.endComponent(componentName);
+            }
+
+            contentHandler.endCalendar();
+        }
+    }
+}

src/test/groovy/net/fortuna/ical4j/extensions/data/CalendarCSVParserTest.groovy

@@ -0,0 +1,38 @@
+package net.fortuna.ical4j.extensions.data
+
+import net.fortuna.ical4j.data.DefaultContentHandler
+import net.fortuna.ical4j.model.TimeZoneRegistryFactory
+import spock.lang.Specification
+
+class CalendarCSVParserTest extends Specification {
+
+    def 'test parsing csv'() {
+        given: 'a csv string'
+        def csv = '''summary,dtstart
+summary 1,20030808
+summary 2,20030809
+summary 3,20030810
+'''
+        when: 'string is parsed'
+        def calendar = null
+        def contentHandler = new DefaultContentHandler((it) -> calendar = it,
+                TimeZoneRegistryFactory.instance.createRegistry())
+        new CalendarCSVParser('vevent').parse(new StringReader(csv), contentHandler)
+
+        then: 'result matched expected'
+        calendar as String == '''BEGIN:VCALENDAR\r
+BEGIN:VEVENT\r
+SUMMARY:summary 1\r
+DTSTART:20030808\r
+END:VEVENT\r
+BEGIN:VEVENT\r
+SUMMARY:summary 2\r
+DTSTART:20030809\r
+END:VEVENT\r
+BEGIN:VEVENT\r
+SUMMARY:summary 3\r
+DTSTART:20030810\r
+END:VEVENT\r
+END:VCALENDAR\r\n'''
+    }
+}