Working on a SpringBoot application using MongoDB as a persistent store.
Using spring data and MongoRepository to access MongoDB.
Using Javers to provide auditting.
If I use mongoRepository.insert(document) followed later by a mongoRepository.save(document) and then use javers to query the changes to that document, javers does not detect the differences between the object inserted and the object saved. It reports only a single change as if the save call was the original object persisted.
If I replace the insert call with a save and let spring data handle whether or not to insert or update, javers reports the expected change.
Example:
Consider the following:
#JaversSpringDataAuditable
public interface SomeDocumentRepository extends MongoRepository<SomeDocument, String> {
}
#Builder
#Data
#Document(collection = "someDocuments")
public class SomeDocument {
#Id
private String id;
private String status;
}
#Service
public class SomeDocumentService {
#Autowired
private SomeDocumentRepository someDocumentRepository;
public SomeDocument insert(SomeDocument doc) {
return someDocumentRepository.insert(doc);
}
public SomeDocument save(SomeDocument doc) {
return someDocumentRepository.save(doc);
}
}
#Service
public class AuditService {
#Autowired
private Javers javers;
public List<Change> getStatusChangesById(String documentId) {
JqlQuery query = QueryBuilder
.byInstanceId(documentId, SomeDocument.class)
.withChangedProperty("status")
.build();
return javers.findChanges(query);
}
}
If I call my service as follows:
var doc = SomeDocument.builder().status("new").build();
doc = someDocumentService.insert(doc);
doc.setStatus("change1");
doc = someDocumentService.save(doc);
and then call the audit service to get the changes:
auditService.getStatusChangesById(doc.getId());
I get a single change with "left" set to a blank and "right" set to "change1".
If I call "save" instead of "insert" like:
var doc = SomeDocument.builder().status("new").build();
doc = someDocumentService.save(doc);
doc.setStatus("change1");
doc = someDocumentService.save(doc);
and then call the audit service to get the changes I get 2 changes, the first being the most recent change with "left" set to "new", and "right" set to "change1" and a second change with "left" set to "" and "right" set to "new".
Is this a bug?
That's a good point. In case of Mongo, Javers covers only the methods from the CrudRepository interface. See https://github.com/javers/javers/blob/master/javers-spring/src/main/java/org/javers/spring/auditable/aspect/springdata/JaversSpringDataAuditableRepositoryAspect.java
Looks like MongoRepository#insert() should be also covered by the aspect.
Feel free to contribute a PR to javers, I will merge it. If you want to discuss the design first - please create a discussion here https://github.com/javers/javers/discussions
Related
I have entity Article I'm trying to retrieve one random record from database collection.
This is entity Article:
#Data
#Document(value = "article")
public class Article {
#Id
private String articleId;
private String title;
private String description;
private String fullArticle;
This is service to save it:
#Override
public Article save(Article article) {
return articleRepository.save(article);
}
And repository:
#Repository
public interface ArticleRepository extends MongoRepository<Article, String> {
}
So, now I'm trying to create a method that will get me one random record from my collection Article also, I want to create a controller so when I go to some endpoint and submit some get method to retrieve one record from the collection and so I can check it in postman or with Swagger. I find some answers to similar question to mine but no one solved my problem, I want to have API for something like that.
You can use $sample in an aggregation query to get a random document:
db.collection.aggregate([
{
"$sample": {
"size": 1
}
}
])
Example here
I've tested the code and it works as expected.
You can create add this method into repository:
#Aggregation(pipeline={"{$sample:{size:1}}"})
AggregationResults<Article> random();
And call from service like this:
#Override
public Article random(){
return articleRepository.random().getMappedResults().stream().findFirst().orElse(null);
// also you can use .orElseThrow() or whatever you want
}
I am using Spring Data JDBC.
I have an entity that has fields annotated with #CreatedDate and #LastModifiedDate.
However, in some cases I want to set these two fields manually.
Is there a way to bypass #CreatedDate and #LastModifiedDate in some cases without removing the annotations from the entity? Or is there a callback that I can add before the entity gets saved?
Populating the auditing information is done by the RelationalAuditingCallback and IsNewAwareAuditingHandler.
The first one basically is the adapter to the module specific part (Spring Data Relational in this case) while the second modifies the entity.
You can implement your own variant of the IsNewAwareAuditingHandler stuff it in a RelationalAuditingCallback and register it as a bean. I did something similar a short time ago in this project on GitHub:
#Bean
RelationalAuditingCallback isNewAwareAuditingHandler(JdbcMappingContext context) {
return new RelationalAuditingCallback(new CustomAuditingHandler(context));
}
private static class CustomAuditingHandler extends IsNewAwareAuditingHandler {
public CustomAuditingHandler(JdbcMappingContext context) {
super(PersistentEntities.of(context));
}
#Override
public Object markAudited(Object source) {
if (!(source instanceof Product)) {
return source;
}
Product product = (Product) source;
if (product.createdDate == null) {
product.createdDate = Instant.now();
}
return source;
}
}
Please consider the logic in the CustomAuditingHandler a place holder. There you should plugin your way to determine if you set the value manually. Maybe your entity implements an interface that offers that information as a transient field, or you store that information in a thread local variable.
if u use above solution on spring boot, it ok. but in use #EnableJdbcAuditing, u should remove #EnableJdbcAuditing.
if it use that, RelationalAuditionCallback is dupulicated on ApplicationContext.
Here's a test based on #Jens Schauder's idea.
https://github.com/yangwansu/try-spring-data-jdbc/blob/main/src/test/java/masil/example/springdata/jdbc/ch9_14_1/ManuallySetupTest.java
There is a replicated mongodb (mongodb-1 - primary, mongodb-2 - secondary, mongodb-3 - secondary).
The app runs through spring-boot-starter-data-mongodb.
Service:
public class FooBarService {
private FooBarRepository repository;
public FooBar method1() {
return repository.someQuery();
}
public FooBar method2() {
return repository.someQuery();
}
}
Repository:
public interface FooBarRepository extends MongoRepository<FooBar, String> {
FooBar someQuery();
}
My question is, how nice to make it so that method1 reads from the primary participant in the mongo replica set, and method2 reads from the secondary participant in the mongo replica set?
Would like to find some way to manage this at the service level (Something like #Transactional, but to select a mongo replica set member).
Can you advise me on any solutions in this regard?
Solution 1: #Meta Annotation
If you want to continue using Repository Interfaces, you can annotate the query method definition with the #Meta annotation which lets you pass flags to indicate to read from a secondary mongodb member.
public interface FooBarRepository extends MongoRepository<FooBar, String> {
#Query("{}")
#Meta(flags = Meta.CursorOption.SECONDARY_READS)
FooBar someQuery();
}
But you cannot control this flag from the service level. You would have to create 2 query methods: One with the flag and one without it. Like someQueryFromSecondary() and someQueryFromPrimary().
Solution 2: Using MongoTemplate
Another option would be to use MongoTemplate directly and set the flag on the Query.
public void someQuery(boolean readFromSecondary) {
var query = Query.query(Criteria.where("someKey").is("1"));
if (readFromSecondary) {
query.allowSecondaryReads();
}
return mongoTemplate.findOne(query, FooBar.class);
}
Regardless which solution you choose: be aware of that reading from secondary members can lead to retrieving stale data. Consider taking a look at the mongodb docs.
I'm using Spring Data MongoDB and Spring Data Rest to create a REST API which allows GET, POST, PUT and DELETE operations on my MongoDB database and it's all working fine except for the update operations (PUT). It only works if I send the full object in the request body.
For example I have the following entity:
#Document
public class User {
#Id
private String id;
private String email;
private String lastName;
private String firstName;
private String password;
...
}
To update the lastName field, I have to send all of the user object, including the password ! which is obviously very wrong.
If I only send the field to update, all the others are set to null in my database. I even tried to add a #NotNull constraints on those fields and now the update won't even happens unless I send all of the user object's fields.
I tried searching for a solution here but I only found the following post but with no solution: How to update particular field in mongo db by using MongoRepository Interface?
Is there a way to implement this ?
Spring Data Rest uses Spring Data repositories to automatically retrieve and manipulate persistent data using Rest calls (check out https://docs.spring.io/spring-data/rest/docs/current/reference/html/#reference).
When using Spring Data MongoDB, you have the MongoOperations interface which is used as a repository for your Rest endpoints.
However MongoOperations currently does not supports specific fields updates !
PS: It will be awesome if they add this feature like #DynamicUpdate in Spring Data JPA
But this doesn't mean it can be done, here's the workaround I did when I had this issue.
Firstly let me explain what we're going to do:
We will create a controller which will override all the PUT operations so that we can implement our own update method.
Inside that update method, we will use MongoTemplate which do have the ability to update specific fields.
N.B. We don't want to re-do these steps for each model in our application, so we will retrieve which model to update dynamically. In order to do that we will create a utility class. [This is optional]
Let's start by adding the org.reflections api to our project dependency which allows us to get all the classes which have a specific annotation (#Document in our case):
<dependency>
<groupId>org.reflections</groupId>
<artifactId>reflections</artifactId>
<version>0.9.12</version>
</dependency>
Then create a new class, called UpdateUtility and add the following methods and also replace the MODEL_PACKAGE attribute with your own package containing your entities:
public class UpdateUtility {
private static final String MODEL_PACKAGE = "com.mycompany.myproject.models";
private static boolean initialized = false;
private static HashMap<String, Class> classContext = new HashMap<>();
private static void init() {
if(!initialized) {
Reflections reflections = new Reflections(MODEL_PACKAGE);
Set<Class<?>> classes = reflections.getTypesAnnotatedWith(Document.class); // Get all the classes annotated with #Document in the specified package
for(Class<?> model : classes) {
classContext.put(model.getSimpleName().toLowerCase(), model);
}
initialized = true;
}
}
public static Class getClassFromType(String type) throws Exception{
init();
if(classContext.containsKey(type)) {
return classContext.get(type);
}
else {
throw new Exception("Type " + type + " does not exists !");
}
}
}
Using this utility class we can retreive the model class to update from it's type.
E.g: UpdateUtility.getClassFromType() will returns User.class
Now let's create our controller:
public class UpdateController {
#Autowired
private MongoTemplate mongoTemplate;
#PutMapping("/{type}/{id}")
public Object update(#RequestBody HashMap<String, Object> fields,
#PathVariable(name = "type") String type,
#PathVariable(name = "id") String id) {
try {
Class classType = UpdatorUtility.getClassFromType(type); // Get the domain class from the type in the request
Query query = new Query(Criteria.where("id").is(id)); // Update the document with the given ID
Update update = new Update();
// Iterate over the send fields and add them to the update object
Iterator iterator = fields.entrySet().iterator();
while(iterator.hasNext()) {
HashMap.Entry entry = (HashMap.Entry) iterator.next();
String key = (String) entry.getKey();
Object value = entry.getValue();
update.set(key, value);
}
mongoTemplate.updateFirst(query, update, classType); // Do the update
return mongoTemplate.findById(id, classType); // Return the updated document
} catch (Exception e) {
// Handle your exception
}
}
}
Now we're able to update the specified fields without changing the calls.
So in your case, the call would be:
PUT http://MY-DOMAIN/user/MY-USER-ID { lastName: "My new last name" }
PS: You can improve it by adding the possibility to update specific field in a nested objects...
Now, I have the next entity. This one is the m1 table of my database.
#Entity(name = "m1")
#Data
public class Information {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private int id;
private String date;
private Double weight_1;
private Double weight_2;
private Double weight_3;
private Double weight_4;
private int working;
}
So, when I do some call to the APIRest it returns me the information corresponding to the m1 table. The controller that I have is the next (simple controller that returns all the information):
#Controller
#RequestMapping(path = "/information")
public class InformationController {
#Autowired
private InformationRepository repository;
#GetMapping(path="/all")
public #ResponseBody List<Information> getAllInformations() {
// This returns a JSON or XML with the users
return repository.findAll();
}
}
The question is: There is any way to change the name of the m1 on runtime. For example can I put the name of the table in the call path and in the API Rest take it?
Maybe this is impossible and I am doing it the bad way I do not know.
EDIT: I mean, can I change the table that the API Rest is taking the data by putting the table that I want in the url/path that I call. For example: in my case the default table/entity that the APIRest take the data is m1, so can I call http://localhost:8080/information/especifictable/all/ where especific table is the table that I want the recieve the data of the database and in the API Rest take that url parameter and change the default m1 with the especifictable.
I do not know if I have explained it well, I do not know how to explain it well.
Such a design would only make sense, if there are two tables in DB, which look the same. if that is the case there is something wrong with your DB design.
Basically it is not possible, to the best of my knowledge.