package com.mhc.dao; 
import org.springframework.stereotype.Repository; 
import com.mhc.entity.Person;
 
@Repository
public interface DeviceCategoryDaoCustom {
 public Person getsFather(Person person); 
}

主接口

public interface DeviceCategoryDao extends
  PagingAndSortingRepository<Person, String>, DeviceCategoryDaoCustom {  
}

上面是我的接口繼承PagingAndSortingRepository、DeviceCategoryDaoCustom（我自己方法的接口）。

我新建一個(gè)類來實(shí)現(xiàn)我自己的接口

package com.mhc.dao; 
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional; 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.NoRepositoryBean;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service; 
import com.mhc.entity.Person;
 
@Repository("crudRepositoryDaoCustom")
class DeviceCategoryDaoImpl implements DeviceCategoryDaoCustom {
 
 @Transactional
 public Person getsFather(Person person) {
  // TODO Auto-generated method stub
  Person father = new Person();
  father = person.getParentPerson();
  return father;
 }
}

在這里有個(gè)需要注意的地方，就是用不用implements的問題，如果用的話，他就會(huì)調(diào)用編譯器的實(shí)現(xiàn)功能去實(shí)現(xiàn)我們自定義的接口也就是：DevicecategoryCustom。

如果去掉的話，他會(huì)去實(shí)現(xiàn)DeviceCategoryDao，那么會(huì)有人問，他怎么去自己找的呢。

事實(shí)上他是根據(jù)后面的Impl來尋找的。他不會(huì)提示@override，不過你寫相同的方法他還是會(huì)覆蓋（覆蓋主接口中的同名方法，如果有的話）DeviceCategoryDao中的同名方法。你可以去嘗試一下。

同時(shí)加上@Repository把他加入到Bean里面，這樣下次用這個(gè)方法的時(shí)候Repository會(huì)自動(dòng)找到他的（話說Spring團(tuán)隊(duì)真心NB）。然后我們交給spring托管、測(cè)試。。。。。Ok 真心贊

Spring Data Jpa自定義方法關(guān)鍵字

關(guān)鍵字	方法名舉例	對(duì)應(yīng)的SQL
And	findByNameAndAge	where name = ? and age = ?
Or	findByNameOrAge	where name = ? or age = ?
Is	findByNameIs	where name = ?
Equals	findByNameEquals	where name = ?
Between	findByAgeBetween	where age between ? and ?
LessThan	findByAgeLessThan	where age < ?
LessThanEquals	findByAgeLessThanEqual	where age <= ?
GreatorThan	findByAgeGreaterThan	where age > ?
GreatorThanEquals	findByAgeGreaterThanEqual	where age >= ?
After	findByAgeAfter	where age > ?
Before	findByAgeBefore	where age < ?
IsNull	findByNameIsNull	where name is null
IsNotNull，NotNull	findByNameIsNotNull，findByNameNotNull	where name is not null
Not	findByNameNot	where name <>?
In	findByAgeIn	where age in (?)
NotIn	findByAgeNotIn	where age not in (?)
NotLike	findByNameNotLike	where name not like ?
Like	findByNameLike	where name like ?
StartingWith	findByNameStartingWith	where name like ‘?%'
EndingWith	findByNameEndingWith	where name like ‘%?'
Containing，Contains	findByNameContaining，findByNameContains	where name like ‘%?%'
OrderBy	findByOrderByAgeDesc	order by age desc
True	findByBossTrue	where boss = true
False	findByBossFalse	where boss = false
IgnoreCase	findByNameIgnoreCase	where UPPER(name) = UPPER(?)