DATAMONGO-693 - More robust handling of host and replica set config in MongoFactoryBean.

MongoFactoryBean now considers empty strings for the replicaPair property as not set at all. The ServerAdressPropertyEditor also returns null as value for empty text strings. Deprecated setter for replica pair on MongoFactoryBean.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/ServerAddressPropertyEditor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 the original author or authors.
+ * Copyright 2011-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import com.mongodb.ServerAddress;
  * 
  * @author Mark Pollack
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public class ServerAddressPropertyEditor extends PropertyEditorSupport {
 
@@ -43,6 +44,11 @@ public class ServerAddressPropertyEditor extends PropertyEditorSupport {
 	@Override
 	public void setAsText(String replicaSetString) {
 
+		if (!StringUtils.hasText(replicaSetString)) {
+			setValue(null);
+			return;
+		}
+
 		String[] replicaSetStringArray = StringUtils.commaDelimitedListToStringArray(replicaSetString);
 		Set<ServerAddress> serverAddresses = new HashSet<ServerAddress>(replicaSetStringArray.length);
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoFactoryBean.java

@@ -15,7 +15,9 @@
  */
 package org.springframework.data.mongodb.core;
 
-import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import org.springframework.beans.factory.DisposableBean;
@@ -24,6 +26,7 @@ import org.springframework.beans.factory.InitializingBean;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.CannotGetMongoDbConnectionException;
+import org.springframework.util.StringUtils;
 
 import com.mongodb.Mongo;
 import com.mongodb.MongoOptions;
@@ -36,6 +39,7 @@ import com.mongodb.WriteConcern;
  * @author Thomas Risberg
  * @author Graeme Rocher
  * @author Oliver Gierke
+ * @author Thomas Darimont
  * @since 1.0
  */
 public class MongoFactoryBean implements FactoryBean<Mongo>, InitializingBean, DisposableBean,
@@ -57,11 +61,38 @@ public class MongoFactoryBean implements FactoryBean<Mongo>, InitializingBean, D
 	}
 
 	public void setReplicaSetSeeds(ServerAddress[] replicaSetSeeds) {
-		this.replicaSetSeeds = Arrays.asList(replicaSetSeeds);
+		this.replicaSetSeeds = filterNonNullElementsAsList(replicaSetSeeds);
 	}
 
+	/**
+	 * @deprecated use {@link #setReplicaSetSeeds(ServerAddress[])} instead
+	 * 
+	 * @param replicaPair
+	 */
+	@Deprecated
 	public void setReplicaPair(ServerAddress[] replicaPair) {
-		this.replicaPair = Arrays.asList(replicaPair);
+		this.replicaPair = filterNonNullElementsAsList(replicaPair);
+	}
+
+	/**
+	 * @param elements the elements to filter <T>
+	 * @return a new unmodifiable {@link List#} from the given elements without nulls
+	 */
+	private <T> List<T> filterNonNullElementsAsList(T[] elements) {
+
+		if (elements == null) {
+			return Collections.emptyList();
+		}
+
+		List<T> candidateElements = new ArrayList<T>();
+
+		for (T element : elements) {
+			if (element != null) {
+				candidateElements.add(element);
+			}
+		}
+
+		return Collections.unmodifiableList(candidateElements);
 	}
 
 	public void setHost(String host) {
@@ -126,15 +157,15 @@ public class MongoFactoryBean implements FactoryBean<Mongo>, InitializingBean, D
 			mongoOptions = new MongoOptions();
 		}
 
-		if (replicaPair != null) {
+		if (!isNullOrEmpty(replicaPair)) {
 			if (replicaPair.size() < 2) {
 				throw new CannotGetMongoDbConnectionException("A replica pair must have two server entries");
 			}
 			mongo = new Mongo(replicaPair.get(0), replicaPair.get(1), mongoOptions);
-		} else if (replicaSetSeeds != null) {
+		} else if (!isNullOrEmpty(replicaSetSeeds)) {
 			mongo = new Mongo(replicaSetSeeds, mongoOptions);
 		} else {
-			String mongoHost = host != null ? host : defaultOptions.getHost();
+			String mongoHost = StringUtils.hasText(host) ? host : defaultOptions.getHost();
 			mongo = port != null ? new Mongo(new ServerAddress(mongoHost, port), mongoOptions) : new Mongo(mongoHost,
 					mongoOptions);
 		}
@@ -146,6 +177,10 @@ public class MongoFactoryBean implements FactoryBean<Mongo>, InitializingBean, D
 		this.mongo = mongo;
 	}
 
+	private boolean isNullOrEmpty(Collection<?> elements) {
+		return elements == null || elements.isEmpty();
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.DisposableBean#destroy()

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/config/ServerAddressPropertyEditorUnitTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import com.mongodb.ServerAddress;
  * Unit tests for {@link ServerAddressPropertyEditor}.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public class ServerAddressPropertyEditorUnitTests {
 
@@ -70,6 +71,16 @@ public class ServerAddressPropertyEditorUnitTests {
 		assertSingleAddressOfLocalhost(editor.getValue());
 	}
 
+	/**
+	 * @see DATAMONGO-693
+	 */
+	@Test
+	public void interpretEmptyStringAsNull() {
+
+		editor.setAsText("");
+		assertNull(editor.getValue());
+	}
+
 	private static void assertSingleAddressOfLocalhost(Object result) throws UnknownHostException {
 
 		assertThat(result, is(instanceOf(ServerAddress[].class)));

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/MongoFactoryBeanIntegrationTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,15 +21,19 @@ import static org.junit.Assert.*;
 import org.junit.Test;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.data.mongodb.config.ServerAddressPropertyEditor;
 import org.springframework.data.mongodb.config.WriteConcernPropertyEditor;
 import org.springframework.test.util.ReflectionTestUtils;
 
+import com.mongodb.Mongo;
+import com.mongodb.ServerAddress;
 import com.mongodb.WriteConcern;
 
 /**
  * Integration tests for {@link MongoFactoryBean}.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 public class MongoFactoryBeanIntegrationTest {
 
@@ -49,4 +53,22 @@ public class MongoFactoryBeanIntegrationTest {
 		MongoFactoryBean bean = factory.getBean("&factory", MongoFactoryBean.class);
 		assertThat(ReflectionTestUtils.getField(bean, "writeConcern"), is((Object) WriteConcern.SAFE));
 	}
+
+	/**
+	 * @see DATAMONGO-693
+	 */
+	@Test
+	public void createMongoInstanceWithHostAndEmptyReplicaSets() {
+
+		RootBeanDefinition definition = new RootBeanDefinition(MongoFactoryBean.class);
+		definition.getPropertyValues().addPropertyValue("host", "localhost");
+		definition.getPropertyValues().addPropertyValue("replicaPair", "");
+
+		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
+		factory.registerCustomEditor(ServerAddress.class, ServerAddressPropertyEditor.class);
+		factory.registerBeanDefinition("factory", definition);
+
+		Mongo mongo = factory.getBean(Mongo.class);
+		assertNotNull(mongo);
+	}
 }