Spring源码学习－spring data jpa源码分析

我先从spring project的git上下载了Spring的源码

Spring data jpa的源码在Spring project的spring-orm/src/main/java/org/springframework/orm/jpa里

这是jpa文件夹结构

最基础的一个接口是org.springframework.data.repository.Repository，这个接口是一个空接口，接口源码为

package org.springframework.data.repository;import java.io.Serializable;/** * Central repository marker interface. Captures the domain type to manage as well as the domain type's id type. General * purpose is to hold type information as well as being able to discover interfaces that extend this one during * classpath scanning for easy Spring bean creation. * <p> * Domain repositories extending this interface can selectively expose CRUD methods by simply declaring methods of the * same signature as those declared in {@link CrudRepository}. *  * @see CrudRepository * @param <T> the domain type the repository manages * @param <ID> the type of the id of the entity the repository manages * @author Oliver Gierke */public interface Repository<T, ID extends Serializable> {}

意思是Ｔ是实体类，ＩＤ是可序列化的主键属性

然后是org.springframework.data.repository.CrudRepository接口，这个接口主要是定义了增删改查的方法，接口源码如下

/* * Copyright 2008-2011 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.springframework.data.repository;import java.io.Serializable;/** * Interface for generic CRUD operations on a repository for a specific type. *  * @author Oliver Gierke * @author Eberhard Wolff */@NoRepositoryBeanpublic interface CrudRepository<T, ID extends Serializable> extends Repository<T, ID> {   /**    * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the    * entity instance completely.    *     * @param entity    * @return the saved entity    */   <S extends T> S save(S entity);   /**    * Saves all given entities.    *     * @param entities    * @return the saved entities    * @throws IllegalArgumentException in case the given entity is (@literal null}.    */   <S extends T> Iterable<S> save(Iterable<S> entities);   /**    * Retrieves an entity by its id.    *     * @param id must not be {@literal null}.    * @return the entity with the given id or {@literal null} if none found    * @throws IllegalArgumentException if {@code id} is {@literal null}    */   T findOne(ID id);   /**    * Returns whether an entity with the given id exists.    *     * @param id must not be {@literal null}.    * @return true if an entity with the given id exists, {@literal false} otherwise    * @throws IllegalArgumentException if {@code id} is {@literal null}    */   boolean exists(ID id);   /**    * Returns all instances of the type.    *     * @return all entities    */   Iterable<T> findAll();   /**    * Returns all instances of the type with the given IDs.    *     * @param ids    * @return    */   Iterable<T> findAll(Iterable<ID> ids);   /**    * Returns the number of entities available.    *     * @return the number of entities    */   long count();   /**    * Deletes the entity with the given id.    *     * @param id must not be {@literal null}.    * @throws IllegalArgumentException in case the given {@code id} is {@literal null}    */   void delete(ID id);   /**    * Deletes a given entity.    *     * @param entity    * @throws IllegalArgumentException in case the given entity is (@literal null}.    */   void delete(T entity);   /**    * Deletes the given entities.    *     * @param entities    * @throws IllegalArgumentException in case the given {@link Iterable} is (@literal null}.    */   void delete(Iterable<? extends T> entities);   /**    * Deletes all entities managed by the repository.    */   void deleteAll();}

还有一个比较重要的Repository是PagingAndSortingRepository，这个接口提供了分页查询和排序查询

/* * Copyright 2008-2010 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.springframework.data.repository;import java.io.Serializable;import org.springframework.data.domain.Page;import org.springframework.data.domain.Pageable;import org.springframework.data.domain.Sort;/** * Extension of {@link CrudRepository} to provide additional methods to retrieve entities using the pagination and * sorting abstraction. *  * @author Oliver Gierke * @see Sort * @see Pageable * @see Page */@NoRepositoryBeanpublic interface PagingAndSortingRepository<T, ID extends Serializable> extends CrudRepository<T, ID> {   /**    * Returns all entities sorted by the given options.    *     * @param sort    * @return all entities sorted by the given options    */   Iterable<T> findAll(Sort sort);   /**    * Returns a {@link Page} of entities meeting the paging restriction provided in the {@code Pageable} object.    *     * @param pageable    * @return a page of entities    */   Page<T> findAll(Pageable pageable);}

好了，今天不早了，明天上午还要跟学长一起去公司交付一个外包项目，要睡了