如何查看Spring Data MongoDB生成的存储库实现? [英] How to see the repository implementation generated by Spring Data MongoDB?

问题描述

Spring Data何时生成存储库的实现?在编译时还是在运行时?我可以看到Spring Data生成的实现存储库实现吗?

When is the implementation for repositories generated by Spring Data? At compile time or runtime? Can I see the implementation repository implementation generated by Spring Data?

推荐答案

tl; dr

不，原因很简单:没有代码生成正在进行.该实现基于代理和方法拦截器，将调用执行委派到正确的位置.

tl;dr

No, for a very simple reason: there's no code generation going on. The implementation is based on proxies and a method interceptor delegating the call executions to the right places.

有效地，方法执行可以由3种类型的代码支持:

Effectively, a method execution can be backed by 3 types of code:

1. CrudRepository的商店特定实现.看一下名为Simple(Jpa|Mongo|Neo4|…)Repository的类型(请参阅JPA特定的一种

1. The store specific implementation of CrudRepository. Have a look for types named Simple(Jpa|Mongo|Neo4|…)Repository (see the JPA specific one here). They have "real" implementations for all of the methods in CrudRepository and PagingAndSortingRepository.

查询方法由QueryExecutorMethodInterceptor.doInvoke(…)有效执行(请参见

Query methods are effectively executed by QueryExecutorMethodInterceptor.doInvoke(…) (see here). It's basically a 3-step-process to find the delegation target and invoke it. The actual execution is done in classes named (Jpa|Mongo|Neo4j…)QueryExecution (see this one for example).

剩下的唯一一件事就是查询派生，它由两个主要部分组成:方法名称解析和查询创建.对于前者，请查看PartTree.它带有一个方法名称和一个基本类型，并且将返回一个已解析的类似AST的结构，如果无法解析属性等，则将引发异常.

The only thing left is the query derivation, which consists of two major parts: method name parsing and query creation. For the former, have a look at PartTree. It takes a method name and a base type and will return you a parsed AST-like structure or throw an exception if it fails to resolve properties or the like.

后者在名为PartTree(Jpa|Mongo|Neo4j|…)Query的类中实现，并委托给其他组件以实际创建商店特定的查询.例如.对于JPA，有趣的地方可能在JpaQueryCreator.PredicateBuilder.build()中(请参阅

The latter is implemented in classes named PartTree(Jpa|Mongo|Neo4j|…)Query and delegates to additional components for actually creating the store specific query. E.g. for JPA the interesting bits are probably in JpaQueryCreator.PredicateBuilder.build() (see here).

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