I have the following Dao class defined:
#Repository
public class MyDao {
private JdbcTemplate jdbcTemplate;
private String myString;
#Autowired
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
I'm using component scanning over the package where MyDao is defined so I do not have a bean definition for MyDao in my Spring configuration file. Is there a way to inject a String into myString without using autowiring? What are my alternatives for this?
Spring comes with the #Value annotation that you can use to inject a string.
http://static.springsource.org/spring/docs/3.0.x/javadoc-api/org/springframework/beans/factory/annotation/Value.html
http://chrislovecnm.com/2010/03/08/spring-3-java-based-configuration-with-value/
There is also a configuration framework called Constretto that allows nested configurations (like json) to be injected.
Related
I'm working on a project that uses SpringBoot 2.0.5 version, Spring Data JPA to persists and retrieve records using JPA. I autowired SimpleJpaRepository in the service layer. But while starting my application, it failed with
"NoSuchBeanDefinitionException"- No qualifying bean of type
'org.springframework.data.jpa.repository.support.SimpleJpaRepository<?, ?>'
available: expected at least 1 bean which qualifies as autowire candidate.
My controller, service and DAO are like below
Controller class:
#Controller
public class MyController{
#Autowired
private MyService<Person,PersonPK> service;
Service layer as
public interface MyService<V,K>{
methods defined
}
#Service("service")
public class MyServiceImpl<V,K> implements MyService<V,K>{
#Autowired
private SimpleJpaRepository<V,K> repository; // This dependency is failing
}
Application as :
#SpringBootApplication (exclude = {SecurityAutoConfiguration.class})
#EnableJpaRepositories
public class MyApplication {
public static void main(String[] args) {
SpringApplication.run(MyApplication.class, args);
}
}
Is my approach incorrect? Is that not the correct way of autowiring the SimpleJpaRepository.
There is no need for me to extend SimpleJpaRepository as Spring provided JPARepository is good for me, for now.
Thanks
You still need to create a repository interface that extends JpaRepisitory, or the spring repository type of your choice.
To quote the spring data documentation:
1.2.1 Defining repository interfaces
As a first step you define a domain class-specific repository interface. The interface must extend
Repository and be typed to the domain class and an ID type. If you
want to expose CRUD methods for that domain type, extend
CrudRepository instead of Repository.
Once you do create a new repository type, you will autowire by that type rather than the SimpleJpaRepository.
One way to get an implementation of the SimpleJpaRepository is by using a Configuration class to create an instance as a bean that you will use inside your service.
#Configuration
public class PersistanceConfiguration {
#PersistenceContext
private EntityManager entityManager;
#Bean
public SimpleJpaRepository<YourEntity, Long> getYourEntitySimpleRepository() {
return new SimpleJpaRepository<>(YourEntity.class, entityManager);
}
}
And inject it to your service as you would do with a JpaRepository, for example:
#Service
public class YourEntityServiceImpl<YourEntity, Long> implements YourEntityService {
private JpaRepository<YourEntity, K> repository;
private SimpleJpaRepository<YourEntity, K> simpleRepository;
#Autowired
public YourEntityServiceImpl(YourEntityRepository repository, SimpleJpaRepository<YourEntity, Long> simpleRepository) {
this.repository = repository;
this.simpleRepository = simpleRepository;
}
}
You should create a repository interface that extending JpaRepisitory.
#Repository
public interface MyRepository extends JpaRepisitory<T, ID> {
//
}
And the you should Autowired in your service class.
#Service("service")
public class MyServiceImpl<V,K> implements MyService<V,K>{
#Autowired
private MyRepository myRepository;
}
I would like to use spring transaction management capabilities within a prototype bean. I did the following:
I've used javax.inject.Provider to create my prototype bean.
I've annotated the method of the prototyped bean with the #Transactional annotation.
Is this the right way of doing it?
#Service
public class SomeService {
#Autowired
private Provider<SomePrototype> myPrototypeProvider;
public void execute() {
SomePrototype somePrototype = myPrototypeProvider.get();
somePrototype.someMethod();
}
}
#Component
#Scope(BeanDefinition.SCOPE_PROTOTYPE)
public class SomePrototype {
#Autowired
private SomeSpringBean someSpringBean;
#Autowired
private SomeRepository someRepository;
#Transactional(propagation = Propagation.REQUIRED)
public void someMethod() {
Result result = someSpringBean.doSomething();
someRepository.save(result);
}
}
The initialisation of transaction-scoped bean requires a proxy. Therefore, if we define a transactional bean as prototype, every that bean is requested, a new proxy is created, and that is not efficient.
What is reason behind this requirement (to have transactional prototype bean)
I am building a Spring Boot application which requires the need for persistence via JDBC and selecting/reading via JPA/Hibernate. I have implemented both of these types of operations using Spring's JdbcTemplate and Spring Data's JpaRepository.
After I persist using JdbcTemplate I am unable to see the data via JpaRepository even though they share the same datasource. I am able to read the data if I use JdbcTemplate.
NOTE: I am using two data sources. One is configured in another class without the #Primary annotation using its own entity manager factory and transaction manager, which is why I've needed to explicitly define it below using Spring Boot's default bean terminology "transactionManager" and "entityManagerFactory".
The following is my embedded database configuration for the primary beans:
#Configuration
#EnableJpaRepositories(basePackages = {"com.repository"})
public class H2DataSourceConfiguration {
private static final Logger log = LoggerFactory.getLogger(H2DataSourceConfiguration.class);
#Bean(destroyMethod = "shutdown")
#Primary
public DataSource dataSource() {
return new EmbeddedDatabaseBuilder()
.setType(EmbeddedDatabaseType.H2)
.setName("dataSource")
.build();
}
#Bean
#Primary
public LocalContainerEntityManagerFactoryBean entityManagerFactory(EntityManagerFactoryBuilder builder, DataSource dataSource) {
return builder
.dataSource(dataSource)
.packages("com.my.domain", "org.springframework.data.jpa.convert.threeten")
.build();
}
#Bean
#Primary
public JpaTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
JpaTransactionManager jpaTransactionManager = new JpaTransactionManager(entityManagerFactory);
return jpaTransactionManager;
}
}
The persistence happens in a different transaction to the reading of the data, however they share the same service.
Both operations happen within the #Transactional annotation. Both repository beans are specified in the same service and also contain the #Transactional annotation. The service looks as follows:
#Service
#Transactional
public class MyServiceImpl implements MyService {
private static final Logger log = LoggerFactory.getLogger(MyServiceImpl.class);
#Autowired
private MyJpaRepository myJpaRepository;
#Autowired
private MyJdbcRepository myJdbcRepository;
...
}
MyJdbcRepositoryImpl.java:
#Repository
#Transactional(propagation = Propagataion.MANDATORY)
public class MyJdbcRepositoryImpl implements MyJdbcRepository {
#Autowired
private NamedParameterJdbcTemplate jdbcTemplate;
// methods within here all use jdbcTemplate.query(...)
}
MyJpaRepository.java:
#Repository
#Transactional(propagation = Propagataion.MANDATORY)
public interface AcquisitionJpaRepository extends JpaRepository<AcquisitionEntity, Long> {
}
Is it at all possible that the jdbctemplate calls are saving to a different h2 database?
The above configuration is correct!
The problem was that the JdbcTemplate calls had the schema owner as a prefix.
For example:
select * from I_AM_SCHEMA.KILL_ME
However, I had both the #Entity annotation and the #Table annotation on the entity object and only specified the table name!
Example:
#Entity
#Table(name = "KILL_ME")
So, we were writing to one table with JdbcTemplate but reading from a completely different other table via JPA/Hibernate due to us missing the prefix.
The correct fix was to prefix the entity name in the #Entity annotation:
#Entity("I_AM_SCHEMA.KILL_ME")
DONE!
public class DictType implements UserType, ParameterizedType {
private String type;
#Inject
private CommonHibernateDao dao;
setter;
getter;
...
When I use dao, a NullPointException will throw
Make sure you created the bean CommonHibernateDao annotated with #Repository and scanning the package containing CommonHibernateDao in your application context.
How do I initialize List inside Object using Spring Annotation
#Component
class Accounts{
private List<Transaction> _transaction;
//getter setter
}
How do I initialize List<Transaction> _transaction; using Spring Annotation or else i
have to define it in xml file.
But i dont want to write any xml file
You can use the Spring Java #Configuration for such a task:
#Configuration
public class SpringConfig {
#Bean
public List<Transaction> transactions() {
...... //Your logic to generate the list..
return transactions;
}
}
And in your Accounts class you have to use #Resource, not #Autowired, the semantics of injecting a list is a little different - if you use #Autowired, any bean of the same type will get injected into the list.
#Component
class Accounts{
#Resource(name="transactions")
private List<Transaction> _transaction;
//getter setter
}
This is pure java solution and there is no xml involved in creating the list..
If Transaction is a Bean with #Service, #Component or #Repository Annotation, you can just write #Autowired on top of your field.
#Component
class Accounts{
#Autowired
private List<Transaction> _transaction;
//getter setter
}