[Spring Data Repositories] study notes -- use existing repository and springrepository

[Spring Data Repositories] study notes -- use existing repository and springrepository

The following are some notes about Spring Data Repositories in Spring-Data-mongoDB. Memo!

I feel that I am still familiar with official materials.

 

Spring Data Repositories objective: to reduce repeated persistent code.

 

Frequently Used repository interfaces,

Repository <-- CurdRepository <-- PagingAndSortingRepository

The last one is mainly used for paging and sorting.

 

Repository usage steps

1. Define the interface

public Interface PersonRepository extends Repository<User,Long>{...}

If we do not want to expose all methods inherited from Repository, we can use @ NoRepositoryBean to mark them.

@NoRepositoryBeanInterface MyBaseRepository<T,ID extends Serializable> extends Repository<T,ID>{T findOne(ID id);T save(T entity);}Interface UserRepository extends MyBaseRepository<User,Long>{User findByEmailAddress(EmailAddress emailAddress);}

In this way, there are only three methods in UserRepository.

 

2. Define methods for the interface defined above

List<Person> findByLastname(String lastname);

Spring can search by method name

public interface PersonRepository extends Repository<User,Long>{List<Person> findByEmailAddressAndLastname(EmailAddress emailAddress, String lastname);List<Person> findDistinctPeopleByLastnameOrFirstname(String lastname, String firstname);List<Person> findByLastnameAndFirstnameAllIgnoreCase(String lastname, String firstname);List<Person> findByLastnameOrderByFirstnameAsc(String lastname);}

• AND, OR, Between, LessThan, GreaterThan, AND which operators are available in the databases used.
• IgnoreCase and AllIgnoreCase
• OrderBy (Asc or Desc)

Supports multi-level queries, such as using x.address.zip Code for search, available

List<Person> findByAddressZipCode(ZipCode zipCode);

Or

List<Person> findByAddress_ZipCode(ZipCode zipCode);

NOTE: If your attribute name contains _, such as first_name, two _ characters must be used to represent underscores.

 

3. Configure Spring for the interface (only xml is listed, and base-package is the package name of the Interface)

<jpa:repositories base-package="com.acme.repositories"/>

You can use include-filter/exclude-filter to filter interfaces.

<repositories base-package="com.acme.repositories"><context:exclude-filter type="regex" expression=".*SomeRepository"/></repositories>

 

4. Obtain the repository instance through injection and use it.

public class SomeClient {@Autowiredprivate PersonRepository repository;public void doSomething(){List<Person> persons = repository.findByLastname("Matthews");}   }

 

Spring-data-mongodb

? 0 = key value in the Parameter
? 1 = value in the Parameter

How can I solve the errors in Appfuse20?