From 31f27e33efb329ded37f1120c8caf1a8f60babc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=CC=88rg=20Prante?= <joergprante@gmail.com>
Date: Mon, 30 May 2022 17:20:31 +0200
Subject: [PATCH] fix CSV generation

---
 .../xbib/datastructures/csv/Generator.java    | 17 ++++++------
 .../csv/test/GeneratorTest.java               | 27 ++++++++++++++++++-
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/datastructures-csv/src/main/java/org/xbib/datastructures/csv/Generator.java b/datastructures-csv/src/main/java/org/xbib/datastructures/csv/Generator.java
index 47ed313..f9df05f 100644
--- a/datastructures-csv/src/main/java/org/xbib/datastructures/csv/Generator.java
+++ b/datastructures-csv/src/main/java/org/xbib/datastructures/csv/Generator.java
@@ -37,19 +37,20 @@ public class Generator implements Constants, Closeable, Flushable {
         return this;
     }
 
-    public void write(String value) throws IOException {
-        if (col > 0) {
-            writer.write(COMMA);
+    public synchronized void write(String value) throws IOException {
+        if (col >= keys.size()) {
+            writer.write(LF);
+            row++;
+            col = 0;
+        } else {
+            if (col > 0) {
+                writer.write(COMMA);
+            }
         }
         if (value != null) {
             writer.write(escape(value));
         }
         col++;
-        if (col > keys.size()) {
-            writer.write(LF);
-            row++;
-            col = 0;
-        }
     }
 
     public int getColumn() {
diff --git a/datastructures-csv/src/test/java/org/xbib/datastructures/csv/test/GeneratorTest.java b/datastructures-csv/src/test/java/org/xbib/datastructures/csv/test/GeneratorTest.java
index 67f71a8..2dd3894 100644
--- a/datastructures-csv/src/test/java/org/xbib/datastructures/csv/test/GeneratorTest.java
+++ b/datastructures-csv/src/test/java/org/xbib/datastructures/csv/test/GeneratorTest.java
@@ -10,7 +10,32 @@ import java.util.Arrays;
 public class GeneratorTest {
 
     @Test
-    public void test() throws IOException {
+    public void testOneColumn() throws IOException {
+        StringWriter writer = new StringWriter();
+        Generator gen = new Generator(writer);
+        gen.keys(Arrays.asList("a"));
+        for (int i = 0; i < 2; i++) {
+            gen.write("val" + i);
+        }
+        gen.close();
+        assertEquals("val0\nval1", writer.toString());
+    }
+
+    @Test
+    public void testTwoColumns() throws IOException {
+        StringWriter writer = new StringWriter();
+        Generator gen = new Generator(writer);
+        gen.keys(Arrays.asList("a", "b"));
+        for (int i = 0; i < 2; i++) {
+            gen.write("val" + i);
+            gen.write("val" + i);
+        }
+        gen.close();
+        assertEquals("val0,val0\nval1,val1", writer.toString());
+    }
+
+    @Test
+    public void testThreeColumns() throws IOException {
         StringWriter writer = new StringWriter();
         Generator gen = new Generator(writer);
         gen.keys(Arrays.asList("a", "b", "c"));