Fix #87

pom.xml

@@ -24,7 +24,7 @@ abstractions.
 
   <properties>
     <jackson.version.annotations>2.6.0</jackson.version.annotations>
-    <jackson.version.core>2.6.0-rc4</jackson.version.core>
+    <jackson.version.core>2.6.1-SNAPSHOT</jackson.version.core>
     <!-- Generate PackageVersion.java into this directory. -->
     <packageVersion.dir>com/fasterxml/jackson/dataformat/csv</packageVersion.dir>
     <packageVersion.package>${project.groupId}.csv</packageVersion.package>

release-notes/VERSION

@@ -4,6 +4,11 @@ Project: jackson-dataformat-csv
 === Releases ===
 ------------------------------------------------------------------------
 
+2.6.1 (not yet released)
+
+#87: Serialization of single Float or Double value leads to incorrect CSV when schema is used
+ (reported by sothmann@github)
+
 2.6.0 (20-Jul-2015)
 
 #72: Recognize the configured "null value" (String) also in reader-infrastructure.

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

@@ -326,10 +326,44 @@ protected CsvSchema _schemaFor(JavaType pojoType, LRUMap<JavaType,CsvSchema> sch
         return result;
     }
 
+    protected boolean _nonPojoType(JavaType t)
+    {
+        if (t.isPrimitive() || t.isEnumType()) {
+            return true;
+        }
+        Class<?> raw = t.getRawClass();
+        // Wrapper types for numbers
+        if (Number.class.isAssignableFrom(raw)) {
+            if ((raw == Byte.class)
+                || (raw == Short.class)
+                || (raw == Character.class)
+                || (raw == Integer.class)
+                || (raw == Long.class)
+                || (raw == Float.class)
+                || (raw == Double.class)
+                ) {
+                return true;
+            }
+        }
+        // Some other well-known non-POJO types
+        if ((raw == Boolean.class)
+                || (raw == String.class)
+                ) {
+            return true;
+        }
+        return false;
+    }
+
     protected void _addSchemaProperties(CsvSchema.Builder builder, AnnotationIntrospector intr,
             boolean typed,
             JavaType pojoType, NameTransformer unwrapper)
     {
+        // 09-Aug-2015, tatu: From [dataformat-csv#87], realized that one can not have
+        //    real schemas for primitive/wrapper
+        if (_nonPojoType(pojoType)) {
+            return;
+        }
+
         BeanDescription beanDesc = getSerializationConfig().introspect(pojoType);
         for (BeanPropertyDefinition prop : beanDesc.findProperties()) {
             // ignore setter-only properties:

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

@@ -1126,7 +1126,7 @@ public String toString()
         sb.append(']');
         sb.append(", header? ").append(usesHeader());
         sb.append(", skipFirst? ").append(skipsFirstDataRow());
-        sb.append(", comments?? ").append(allowsComments());
+        sb.append(", comments? ").append(allowsComments());
 
         sb.append(']');
         return sb.toString();

src/test/java/com/fasterxml/jackson/dataformat/csv/ser/TestGenerator.java

@@ -4,6 +4,7 @@
 import com.fasterxml.jackson.core.JsonGenerationException;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.fasterxml.jackson.dataformat.csv.CsvFactory;
 import com.fasterxml.jackson.dataformat.csv.CsvGenerator;
@@ -243,6 +244,31 @@ public void testRawWrites() throws Exception
         assertEquals("a,b,foobar\n", w.toString());
     }
 
+    // for [dataformat-csv#87]
+    public void testSerializationOfPrimitivesToCsv() throws Exception
+    {
+        CsvMapper mapper = new CsvMapper();
+        /*
+        testSerializationOfPrimitiveToCsv(mapper, String.class, "hello world", "\"hello world\"\n");
+        testSerializationOfPrimitiveToCsv(mapper, Boolean.class, true, "true\n");
+        testSerializationOfPrimitiveToCsv(mapper, Integer.class, 42, "42\n");
+        testSerializationOfPrimitiveToCsv(mapper, Long.class, 42L, "42\n");
+        */
+        testSerializationOfPrimitiveToCsv(mapper, Short.class, (short)42, "42\n");
+        testSerializationOfPrimitiveToCsv(mapper, Double.class, 42.33d, "42.33\n");
+        testSerializationOfPrimitiveToCsv(mapper, Float.class, 42.33f, "42.33\n");
+    }
+
+    private <T> void testSerializationOfPrimitiveToCsv(final CsvMapper mapper,
+            final Class<T> type, final T value, final String expectedCsv) throws Exception
+    {
+        CsvSchema schema = mapper.schemaFor(type);
+System.err.println("Schema for "+type+" == "+schema);       
+        ObjectWriter writer = mapper.writer(schema);
+        String csv = writer.writeValueAsString(value);
+        assertEquals(expectedCsv, csv);
+    }    
+
     /*
     /**********************************************************************
     /* Secondary test methods