java - 为什么 Maven 在我使用 Spring-Data 时添加依赖的 Hibernate Jars

Question

每当我像下面这样添加依赖项时，maven 还会添加 hibernate-entitymanager-4.3.10.jar、hibernate-core-4.3.10.jar...

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.rajkishan</groupId>
<artifactId>Test</artifactId>
<packaging>war</packaging>
<version>1.0.-SNAPSHOT</version>

<name>Test</name>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java-version>1.8</java-version>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <start-class>com.rajkishan.Application</start-class>
</properties>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.2.5.RELEASE</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <!-- Spring Data JPA -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>
    <!--Manual-->
    <dependency>
        <groupId>com.microsoft.sqlserver</groupId>
        <artifactId>sqljdbc41</artifactId>
        <version>4.1</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <showDeprecation>true</showDeprecation>
                <compilerArgs>
                    <arg>-verbose</arg>
                    <arg>-Xlint:unchecked</arg>
                </compilerArgs>
            </configuration>
        </plugin>
    </plugins>
</build>

Spring-DATA 和 Hibernate 不是不同的 JPA 实现吗？

Answer 1

spring-boot-starter-data-jpa POM 依赖项引入了几个 JPA 依赖项，包括 Hibernate。来自官方Spring documentation :

The spring-boot-starter-data-jpa POM provides a quick way to get started. It provides the following key dependencies:

Hibernate — One of the most popular JPA implementations.
Spring Data JPA — Makes it easy to implement JPA-based repositories.
Spring ORMs — Core ORM support from the Spring Framework.

因此，Spring 数据 JPA JAR 旨在成为将 Hibernate 依赖项拉入项目的一种方式。