Minor cleanup with tests

Added converter on saving in db user

spring-data-mongodb/src/main/java/org/baeldung/annotation/CascadeSave.java

@@ -0,0 +1,12 @@
+package org.baeldung.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface CascadeSave {
+
+}

spring-data-mongodb/src/main/java/org/baeldung/config/MongoConfig.java

@@ -1,9 +1,16 @@
 package org.baeldung.config;
 
+import java.util.ArrayList;
+import java.util.List;
+
+
+import org.baeldung.converter.UserWriterConverter;
 import org.baeldung.event.CascadingMongoEventListener;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.config.AbstractMongoConfiguration;
+import org.springframework.data.mongodb.core.convert.CustomConversions;
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
 
 import com.mongodb.Mongo;
@@ -13,6 +20,8 @@ import com.mongodb.MongoClient;
 @EnableMongoRepositories(basePackages = "org.baeldung.repository")
 public class MongoConfig extends AbstractMongoConfiguration {
 
+    private List<Converter<?,?>> converters = new ArrayList<Converter<?,?>>();
+
     @Override
     protected String getDatabaseName() {
         return "test";
@@ -32,4 +41,10 @@ public class MongoConfig extends AbstractMongoConfiguration {
     public CascadingMongoEventListener cascadingMongoEventListener(){
         return new CascadingMongoEventListener();
     }
+    
+    @Override
+    public CustomConversions customConversions() {
+       converters.add(new UserWriterConverter());
+       return new CustomConversions(converters);
+    }
 }

spring-data-mongodb/src/main/java/org/baeldung/converter/UserWriterConverter.java

@@ -0,0 +1,25 @@
+package org.baeldung.converter;
+
+import org.springframework.stereotype.Component;
+import org.baeldung.model.User;
+import org.springframework.core.convert.converter.Converter;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBObject;
+
+@Component
+public class UserWriterConverter implements Converter<User, DBObject> {
+    @Override
+    public DBObject convert(User user) {
+        DBObject dbObject = new BasicDBObject();
+        dbObject.put("name", user.getName());
+        dbObject.put("age", user.getAge());
+        if (user.getEmailAddress() != null) {
+            DBObject emailDbObject = new BasicDBObject();
+            emailDbObject.put("value", user.getEmailAddress().getValue());
+            dbObject.put("email", emailDbObject);
+        }
+        dbObject.removeField("_class");
+        return dbObject;
+    }
+}

spring-data-mongodb/src/main/java/org/baeldung/event/CascadingMongoEventListener.java

@@ -0,0 +1,37 @@
+package org.baeldung.event;
+
+import org.baeldung.annotation.CascadeSave;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.mongodb.core.MongoOperations;
+import org.springframework.data.mongodb.core.mapping.DBRef;
+import org.springframework.data.mongodb.core.mapping.event.AbstractMongoEventListener;
+import org.springframework.util.ReflectionUtils;
+
+import java.lang.reflect.Field;
+
+public class CascadingMongoEventListener extends AbstractMongoEventListener<Object> {
+    @Autowired
+    private MongoOperations mongoOperations;
+
+    @Override
+    public void onBeforeConvert(final Object source) {
+        ReflectionUtils.doWithFields(source.getClass(), new ReflectionUtils.FieldCallback() {
+
+            public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
+                ReflectionUtils.makeAccessible(field);
+
+                if (field.isAnnotationPresent(DBRef.class) && field.isAnnotationPresent(CascadeSave.class)) {
+                    final Object fieldValue = field.get(source);
+
+                    if (fieldValue != null) {
+                        DbRefFieldCallback callback = new DbRefFieldCallback();
+
+                        ReflectionUtils.doWithFields(fieldValue.getClass(), callback);
+
+                        mongoOperations.save(fieldValue);
+                    }
+                }
+            }
+        });
+    }
+}

spring-data-mongodb/src/main/java/org/baeldung/event/DbRefFieldCallback.java

@@ -0,0 +1,22 @@
+package org.baeldung.event;
+
+import java.lang.reflect.Field;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.util.ReflectionUtils;
+
+public class DbRefFieldCallback implements ReflectionUtils.FieldCallback {
+    private boolean idFound;
+
+    public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
+        ReflectionUtils.makeAccessible(field);
+
+        if (field.isAnnotationPresent(Id.class)) {
+            idFound = true;
+        }
+    }
+
+    public boolean isIdFound() {
+        return idFound;
+    }
+}

spring-data-mongodb/src/main/java/org/baeldung/model/EmailAddress.java

@@ -0,0 +1,34 @@
+package org.baeldung.model;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Document
+public class EmailAddress {
+    @Id
+    private String id;
+    private String value;
+    
+    public EmailAddress(){
+    }
+    
+    public EmailAddress(String value) {
+        this.value =  value;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+}

spring-data-mongodb/src/main/java/org/baeldung/model/User.java

@@ -20,11 +20,21 @@ public class User {
     private String name;
 
     private Integer age;
+    
     @DBRef
     @Field("email")
     @CascadeSave
-
     private EmailAddress emailAddress;
+    
+    public User(){
+    }
+
+    
+    public User(String name, Integer age, String value){
+        this.name = name;
+        this.age = age;
+        this.emailAddress = new EmailAddress(value);
+    }
 
     public String getId() {
         return id;

spring-data-mongodb/src/test/java/org/baeldung/mongotemplate/MongoTemplateQueryIntegrationTest.java

@@ -34,7 +34,9 @@ public class MongoTemplateQueryIntegrationTest {
 
     @Before
     public void testSetup() {
-        mongoTemplate.createCollection(User.class);
+        if (!mongoTemplate.collectionExists(User.class)) {
+            mongoTemplate.createCollection(User.class);
+        }
     }
 
     @After
@@ -148,7 +150,7 @@ public class MongoTemplateQueryIntegrationTest {
     }
 
     @Test
-    public void givenExisted() {
+    public void whenSavingUserWithEmailAddress_thenUserandEmailAddressSaved() {
         User user = new User();
         user.setName("Brendan");
         EmailAddress emailAddress = new EmailAddress();

spring-data-mongodb/src/test/java/org/baeldung/repository/BaseQueryIntegrationTest.java

@@ -17,7 +17,9 @@ public class BaseQueryIntegrationTest {
 
     @Before
     public void testSetup() {
-        mongoOps.createCollection(User.class);
+        if (!mongoOps.collectionExists(User.class)) {
+            mongoOps.createCollection(User.class);
+        }
     }
 
     @After

spring-data-mongodb/src/test/java/org/baeldung/repository/UserRepositoryIntegrationTest.java

@@ -34,7 +34,9 @@ public class UserRepositoryIntegrationTest {
 
     @Before
     public void testSetup() {
-        mongoOps.createCollection(User.class);
+        if (!mongoOps.collectionExists(User.class)) {
+            mongoOps.createCollection(User.class);
+        }
     }
 
     @After
@@ -67,12 +69,11 @@ public class UserRepositoryIntegrationTest {
         mongoOps.insert(user);
 
         user = mongoOps.findOne(Query.query(Criteria.where("name").is("Jack")), User.class);
-        final String id = user.getId();
 
         user.setName("Jim");
         userRepository.save(user);
 
-        assertThat(mongoOps.findOne(Query.query(Criteria.where("id").is(id)), User.class).getName(), is("Jim"));
+        assertThat(mongoOps.findAll(User.class).size(), is(2));
     }
 
     @Test