Why #Autowired not working all the time? - mongodb

Question

Im trying to setup mongodb with SpringBoot and im not using context.xml but trying to configure with configuration class and annotations.
package com.configuration;
import com.mongodb.Mongo;
import com.mongodb.MongoClient;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoConfiguration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
#Configuration
#EnableMongoRepositories(basePackages = "com.mongo")
public class MongoConfig extends AbstractMongoConfiguration {
#Override
protected String getDatabaseName() {
return "mongodbname";
}
#Override
public Mongo mongo() throws Exception {
return new MongoClient("127.0.0.1", 27017);
}
#Override
protected String getMappingBasePackage() {
return "com.mongo";
}
}
My repository looks like this :
package com.mongo.repositories;
import com.mongo.documents.Sequence;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.stereotype.Repository;
import java.util.List;
#Repository("sequenceRepository")
public class SequenceRepository{
#Autowired
private MongoTemplate mongoTemplate;
public Sequence findOne(Query query){
return this.mongoTemplate.findOne(query,Sequence.class);
}
public List<Sequence> find(Query query){
return this.mongoTemplate.find(query,Sequence.class);
}
public void save(Sequence object){
this.mongoTemplate.save(object);
}
public void delete(Sequence object){
this.mongoTemplate.remove(object);
}
}
If i use like this in the rest controller it is working properly :
package com.controllers;
import com.mongo.documents.Sequence;
import com.mongo.repositories.SequenceRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class IndexController {
#Autowired
private SequenceRepository sequenceRepository;
#RequestMapping("/")
public String index(){
Sequence sequence = new Sequence();
sequence.setClassName("class.Test");
sequence.setActual(1);
sequenceRepository.save(sequence);
return "index";
}
}
But if i want to use the SequenceRepository inside the Sequence document like this :
package com.mongo.documents;
import com.mongo.repositories.SequenceRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
#Document
public class Sequence {
#Autowired
private SequenceRepository sequenceRepository;
#Id
private String id;
private String className;
private int actual;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
public int getActual() {
return actual;
}
public void setActual(int actual) {
this.actual = actual;
}
public void save(){
this.sequenceRepository.save(this);
}
public void delete(){
this.sequenceRepository.delete(this);
}
}
After that I change the code in the controller to :
package com.controllers;
import com.mongo.documents.Sequence;
import com.mongo.repositories.SequenceRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class IndexController {
#Autowired
private SequenceRepository sequenceRepository;
#RequestMapping("/")
public String index(){
Sequence sequence = new Sequence();
sequence.setClassName("class.Test");
sequence.setActual(1);
sequence.save();
return "index";
}
}
I got a nullPointerExceeption at this point in the save() method.

Answer 1

There is no need to inject your Repository inside your Domain object Sequence as it is really bad design to have a dependency between the domain objects and your repository classes.
To follow some good practices, your Service classes or if you don't need a Service layer, your Controller classes should inject your Repository beans.
In your last code snippet your are already doing it, but the .save() method should be called on your repository SequenceRepository and not on the domain object Sequence.
An example could be the following:
#RestController
public class IndexController {
#Autowired
private SequenceRepository sequenceRepository;
#RequestMapping("/")
public String index(){
Sequence sequence = new Sequence();
sequence.setClassName("class.Test");
sequence.setActual(1);
// now let's save it
sequenceRepository.save(sequence);
return "index";
}
}

Answer 2

You can only autowire Spring-managed components into other Spring-managed components. Your sequence object is not a component (not annotated with #Component, #Service, #Repository or #Controller etc.)
I suggest you follow rieckpil's advice.