[OLINGO-1568] Add handling of special case precision/scale

lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientPrimitiveValueImpl.java

@@ -206,12 +206,16 @@ public class ClientPrimitiveValueImpl extends AbstractClientValue implements Cli
       return value.toString();
     } else {
       try {
-        // TODO: set facets
         Integer precision = Constants.DEFAULT_PRECISION;
         Integer scale = Constants.DEFAULT_SCALE;
         if (typeKind.equals(EdmPrimitiveTypeKind.Decimal) && value instanceof BigDecimal) {
             precision = ((BigDecimal) value).precision();
             scale = ((BigDecimal) value).scale();
+            if (precision == 0) {
+              precision = null;
+            } else if (scale > precision) {
+              precision = scale;
+            }
         }
         return type.valueToString(value, null, null, precision, scale, null);
       } catch (EdmPrimitiveTypeException e) {

lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonSerializer.java

@@ -296,16 +296,20 @@ public class JsonSerializer implements ODataSerializer {
         jgen.writeString(value.toString()); // This might not be valid OData.
       }
     } else {
-      // TODO: add facets
+      Integer precision = Constants.DEFAULT_PRECISION;
-      Integer precesion = Constants.DEFAULT_PRECISION;
       Integer scale = Constants.DEFAULT_SCALE;
       if(kind == EdmPrimitiveTypeKind.Decimal && value instanceof BigDecimal){
           BigDecimal bigDecimal = (BigDecimal)value;
-          precesion = bigDecimal.precision();
+          precision = bigDecimal.precision();
           scale = bigDecimal.scale();
+          if (precision == 0) {
+            precision = null;
+          } else if (scale > precision) {
+            precision = scale;
+          }
       }
       final String serialized = EdmPrimitiveTypeFactory.getInstance(kind)
-          .valueToString(value, null, null, precesion, scale, null);
+          .valueToString(value, null, null, precision, scale, null);
 
       if (isIEEE754Compatible && (kind == EdmPrimitiveTypeKind.Int64 || kind == EdmPrimitiveTypeKind.Decimal)
           || !NUMBER_TYPES.contains(kind)) {

lib/client-core/src/test/java/org/apache/olingo/client/core/PrimitiveValueTest.java

@@ -20,6 +20,7 @@ package org.apache.olingo.client.core;
 
 import static org.junit.Assert.assertEquals;
 
+import java.math.BigDecimal;
 import java.util.Calendar;
 
 import org.apache.olingo.client.api.domain.ClientValue;
@@ -64,4 +65,16 @@ public class PrimitiveValueTest extends AbstractTest {
 
     assertEquals("2013-01-10", value.asPrimitive().toString());
   }
+
+  @Test
+  public void testBigDecimalToStringConversion() throws EdmPrimitiveTypeException {
+    final ClientValue leadingZerosDecimalValue = client.getObjectFactory().newPrimitiveValueBuilder()
+            .setType(EdmPrimitiveTypeKind.Decimal).setValue(new BigDecimal("0.01")).build();
+    final ClientValue arbitraryPrecisionDecimalValue = client.getObjectFactory().newPrimitiveValueBuilder()
+            .setType(EdmPrimitiveTypeKind.Decimal).setValue(new BigDecimal(0.01)).build();
+
+    assertEquals("0.01", leadingZerosDecimalValue.asPrimitive().toString());
+    assertEquals("0.01000000000000000020816681711721685132943093776702880859375",
+        arbitraryPrecisionDecimalValue.asPrimitive().toString());
+  }
 }

lib/client-core/src/test/java/org/apache/olingo/client/core/serialization/JsonSerializerTest.java

@@ -19,6 +19,7 @@ import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
 
 import java.io.StringWriter;
+import java.math.BigDecimal;
 
 import org.apache.olingo.client.api.ODataClient;
 import org.apache.olingo.client.api.domain.ClientEntity;
@@ -66,6 +67,33 @@ public class JsonSerializerTest {
 
     JsonSerializer jsonSerializer = new JsonSerializer(false, ContentType.JSON_FULL_METADATA);
 
+    StringWriter writer = new StringWriter();
+    jsonSerializer.write(writer, odataClient.getBinder().getEntity(clientEntity));
+    assertThat(writer.toString(), is(expectedJson));
+  }
+  @Test
+  public void testClientEntityJSONWithBigDecimal() throws ODataSerializerException {
+    String expectedJson = "{\"@odata.type\":\"#test.testClientEntity\","
+            + "\"testLeadingZerosDecimal@odata.type\":\"Decimal\","
+            + "\"testLeadingZerosDecimal\":0.01,"
+            + "\"testArbitraryPrecisionDecimal@odata.type\":\"Decimal\","
+            + "\"testArbitraryPrecisionDecimal\":0.01000000000000000020816681711721685132943093776702880859375}";
+
+    ODataClient odataClient = ODataClientFactory.getClient();
+    ClientObjectFactory objFactory = odataClient.getObjectFactory();
+    ClientEntity clientEntity = objFactory.newEntity(new FullQualifiedName("test", "testClientEntity"));
+
+    clientEntity.getProperties().add(
+            objFactory.newPrimitiveProperty(
+                    "testLeadingZerosDecimal",
+                    objFactory.newPrimitiveValueBuilder().buildDecimal(new BigDecimal("0.01"))));
+    clientEntity.getProperties().add(
+            objFactory.newPrimitiveProperty(
+                    "testArbitraryPrecisionDecimal",
+                    objFactory.newPrimitiveValueBuilder().buildDecimal(new BigDecimal(0.01))));
+
+    JsonSerializer jsonSerializer = new JsonSerializer(false, ContentType.JSON_FULL_METADATA);
+
     StringWriter writer = new StringWriter();
     jsonSerializer.write(writer, odataClient.getBinder().getEntity(clientEntity));
     assertThat(writer.toString(), is(expectedJson));