Fix duplicate key exception for class path catalog loader.

catalog-core/src/main/java/uk/gov/justice/schema/catalog/ClasspathCatalogLoader.java

@@ -12,6 +12,7 @@
 import java.net.URL;
 import java.util.List;
 import java.util.Map;
+import java.util.function.BinaryOperator;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 
@@ -43,8 +44,9 @@ public ClasspathCatalogLoader(final ObjectMapper objectMapper,
      * @return All found {@link Catalog}s mapped by their URIs
      */
     public Map<URI, Catalog> getCatalogs() {
+        final BinaryOperator<Catalog> duplicateKeyMapper = (c1, c2) -> c1;
         return listAllCatalogsFromClasspath().stream()
-                .collect(toMap(urlConverter::toUri, this::loadCatalog));
+                .collect(toMap(urlConverter::toUri, this::loadCatalog, duplicateKeyMapper));
     }
 
     private Catalog loadCatalog(final URL catalogUrl) {

catalog-core/src/test/java/uk/gov/justice/schema/catalog/ClasspathCatalogLoaderTest.java

@@ -1,10 +1,12 @@
 package uk.gov.justice.schema.catalog;
 
+import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.startsWith;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import uk.gov.justice.schema.catalog.domain.Catalog;
@@ -49,7 +51,7 @@ public void shouldThrowExceptionIfLoadingFileThrowsIOException() throws Exceptio
         final URL url = new URL("file://src/code/my-file.txt");
         final URI uri = url.toURI();
 
-        when(classpathResourceLoader.getResources( "META-INF/schema_catalog.json")).thenReturn(singletonList(url));
+        when(classpathResourceLoader.getResources("META-INF/schema_catalog.json")).thenReturn(singletonList(url));
         when(urlConverter.toUri(url)).thenReturn(uri);
         when(objectMapper.readValue(url, Catalog.class)).thenThrow(ioException);
 
@@ -78,4 +80,22 @@ public void shouldThrowExceptionIfLoadingResourcesThrowsIOException() throws Exc
 
         }
     }
+
+    @Test
+    public void shouldNotThrowExceptionIfDuplicateKeyAdded() throws Exception {
+
+        final URL url = new URL("file://src/code/my-file.txt");
+        final URI uri = url.toURI();
+
+        when(classpathResourceLoader.getResources("META-INF/schema_catalog.json")).thenReturn(asList(url, url));
+        when(urlConverter.toUri(url)).thenReturn(uri);
+        when(objectMapper.readValue(url, Catalog.class)).thenReturn(mock(Catalog.class));
+
+        try {
+            classpathCatalogLoader.getCatalogs();
+        } catch (final Exception notExpected) {
+            fail("Should not have thrown any exception");
+        }
+
+    }
 }