BUG-37449 create a type return can be improved to return better json

typesystem/src/main/java/org/apache/hadoop/metadata/typesystem/types/DataTypes.java

@@ -22,6 +22,7 @@ import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.hadoop.metadata.MetadataException;
 import org.apache.hadoop.metadata.typesystem.IReferenceableInstance;
 import org.apache.hadoop.metadata.typesystem.persistence.Id;
@@ -455,7 +456,7 @@ public class DataTypes {
 
         @Override
         public String convert(Object val, Multiplicity m) throws MetadataException {
-            if (val != null) {
+            if (StringUtils.isNotBlank((CharSequence) val)) {
                 return val.toString();
             }
             return convertNull(m);

webapp/src/test/java/org/apache/hadoop/metadata/web/resources/EntityJerseyResourceIT.java

@@ -51,6 +51,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.testng.Assert;
 import org.testng.annotations.BeforeClass;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 import javax.ws.rs.HttpMethod;
@@ -95,6 +96,26 @@ public class EntityJerseyResourceIT extends BaseResourceIT {
         }
     }
 
+    @DataProvider
+    public Object[][] invalidAttrValues() {
+        return new Object[][]{
+                {null}, {""}, {" "}};
+    }
+
+    @Test(dataProvider = "invalidAttrValues")
+    public void testEntityInvalidValue(String value) throws Exception {
+        Referenceable databaseInstance = new Referenceable(DATABASE_TYPE);
+        databaseInstance.set("name", randomString());
+        databaseInstance.set("description", value);
+
+        try {
+            createInstance(databaseInstance);
+            Assert.fail("Exptected MetadataServiceException");
+        } catch(MetadataServiceException e) {
+            Assert.assertEquals(e.getStatus(), ClientResponse.Status.BAD_REQUEST);
+        }
+    }
+
     @Test
     public void testSubmitEntityWithBadDateFormat() throws Exception {