Fix bug in batch parameter handling

build.xml

@@ -10,7 +10,7 @@
     <property name="lib" value="${basedir}/lib" />
     <property name="test-lib" value="${basedir}/lib-test" />
 
-    <property name="version" value="0.9.3" />
+    <property name="version" value="0.9.4" />
 
   	<property name="product-jar" value="${basedir}/${ant.project.name}-${version}.jar" />
   </target>

src/org/dt/japper/ParameterParser.java

@@ -310,7 +310,7 @@ private boolean handleParamName(int ch) {
 
   private void addParamRef() {
     String name = paramName.toString().toLowerCase();
-    if (parsingForBatch) {
+    if (parsingForBatch && !paramValueMap.containsKey(name)) {
       paramValueMap.put(name, new ParameterValue(name, null));
     }
 

test-src/org/dt/japper/BatchParameterReuseTest.java

@@ -0,0 +1,41 @@
+package org.dt.japper;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.sql.Connection;
+
+import static org.dt.japper.Japper.paramLists;
+import static org.dt.japper.Japper.params;
+import static org.junit.Assert.assertEquals;
+
+public class BatchParameterReuseTest {
+
+    private static TestData testData;
+
+    @BeforeClass
+    public static void setupDB() throws Exception {
+        testData = new TestData();
+        testData.create();
+    }
+
+    @Test
+    public void insertBatch() throws Exception {
+        String sql =
+                " insert into part(partno, description, part_type, dyn_field) " +
+                        " values(:PARTNO, :DESCRIPTION, :PARTNO, :DYN_FIELD) "
+                ;
+
+        Connection conn = testData.connect();
+        try {
+            int rowsAffected = Japper.executeBatch(conn, sql, paramLists(
+                    params("PARTNO", "ZZ1", "DESCRIPTION", "Batch part 1", "PART_TYPE", "FAB", "DYN_FIELD", "C:30")
+                    , params("PARTNO", "ZZ2", "PART_TYPE", "BUY", "DESCRIPTION", "Batch part 2")
+            ));
+            assertEquals(2, rowsAffected);
+        }
+        finally {
+            try { conn.close(); } catch (Exception ignored) {}
+        }
+    }
+}