我想利用 XML 配置文件中的一些 Spring Boot 自动配置的 bean，但是当我尝试这样做时，我总是遇到异常和错误。

例如，如果我的类路径上有与数据相关的库，Spring Boot 将自动配置一个 DataSource 对象，我可以将其 Autowiring 到我自己的 bean 和类中，如下所示:

@Configuration
@ImportResource("classpath:xmlconfig.xml")
public class Config {

    // This works!!
    @Autowired
    private DataSource dataSource;

    @Bean
    public ClassThatRequiresADataSource() {
        ClassThatRequiresADataSource foo = new ClassThatRequiresADataSource();
        foo.setDataSource(dataSource);
        return foo;
    }
}

但是，如果我尝试在 XML 配置文件中做同样的事情，我会得到一个异常。我一直在通过向我的主配置类添加 @ImportResource("classpath:xmlconfig.xml") 来引导 XML 配置文件。这是我正在谈论的一个示例...在 xmlconfig.xml 内部:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!-- THIS DOES NOT WORK! -->
    <bean id="anotherClassThatRequiresADataSource" class="my.package.AnotherClassThatRequiresADataSource">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

尽管 dataSource 是一个有效的、自动配置的 Bean 名称，但在运行 Spring Boot 应用程序时，上述内容会出现异常。我还尝试使用自动配置的 ConnectionFactory(在类路径上使用 ActiveMQ)和在类路径上使用 Hibernate 和 JPA 的 EntityManagerFactory，但这些都不起作用.

基本上，我要问的是:什么相当于将 Spring Boot 自动配置的 bean Autowiring 到 XML 配置文件中？

这是我的主要 Spring Boot 入口点，只是所有文档中列出的标准类:

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
}

我主要在 Spring Integration 应用程序中使用它，其中 Java 配置尚未得到很好的支持，并且框架的核心是基于 XML 配置的，但我想使用 Spring Boot 自动配置 DataSource 和 ConnectionFactory bean 中的一些集成元素。

编辑:@AdilF 提供的答案适用于 dataSource bean，但类似的配置不适用于 connectionFactory bean。请参阅以下 GitHub 项目的演示代码来说明这一点:

https://github.com/ccampo133/autoconfig-test/tree/master

如果有人能弄清楚如何正确连接 connectionFactory bean，我将不胜感激。

以下是说明这一点的大部分代码:

Application.java

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Config.java

@Configuration
@ImportResource("classpath:/resources/config.xml")
public class Config { }

FooService.java

@Service
public class FooService {

    final private Logger logger = LoggerFactory.getLogger(FooService.class);

    @Autowired
    private DataSource dataSource;

    @Autowired
    private ConnectionFactory connectionFactory;

    @Autowired
    private EntityManagerFactory entityManagerFactory;

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource, "dataSource is null!");
        logger.info("dataSource not null");

        Assert.notNull(connectionFactory, "connectionFactory is null!");
        logger.info("connectionFactory not null");

        Assert.notNull(entityManagerFactory, "entityManagerFactory is null!");
        logger.info("entityManagerFactory is not null");
    }
}

BarService.java

public class BarService {

    final private Logger logger = LoggerFactory.getLogger(BarService.class);

    private DataSource dataSource;

    private ConnectionFactory connectionFactory;

    private EntityManagerFactory entityManagerFactory;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public void setConnectionFactory(ConnectionFactory connectionFactory) {
        this.connectionFactory = connectionFactory;
    }

    public void setEntityManagerFactory(final EntityManagerFactory entityManagerFactory) {
        this.entityManagerFactory = entityManagerFactory;
    }

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource, "dataSource is null!");
        logger.info("dataSource not null");

        Assert.notNull(connectionFactory, "connectionFactory is null!");
        logger.info("connectionFactory not null");

        Assert.notNull(entityManagerFactory, "entityManagerFactory is null!");
        logger.info("entityManagerFactory is not null");
    }
}

config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="barService" class="app.service.BarService">
        <!-- THIS WORKS! -->
        <property name="dataSource" ref="dataSource"/>

        <!-- THIS DOESN'T WORK! -->
        <property name="connectionFactory" ref="connectionFactory"/>
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>

</beans>

build.gradle

buildscript {
    ext {
        junitVersion = "4.11"
        springBootVersion = "1.1.5.RELEASE"
        springIntegrationVersion = "4.0.3.RELEASE"
        activeMqVersion = "5.7.0"
    }

    repositories {
        mavenCentral()
    }

    dependencies {
        classpath "org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}"
    }
}

apply plugin: "java"
apply plugin: "eclipse"
apply plugin: "idea"
apply plugin: "spring-boot"

configurations {
    providedRuntime
}

jar {
    baseName = "autoconfig-test"
    version = "0.0.1-SNAPSHOT"
}

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/libs-milestone/" }
}

dependencies {
    // Spring Boot starters
    compile "org.springframework.boot:spring-boot-starter-data-jpa:${springBootVersion}"
    compile "org.springframework.boot:spring-boot-starter-integration:${springBootVersion}"
    compile "org.springframework.integration:spring-integration-jms:${springIntegrationVersion}"

    // ActiveMQ
    compile "org.apache.activemq:activemq-core:${activeMqVersion}"

    // Persistence
    runtime "com.h2database:h2"

    // Test
    testCompile "junit:junit:${junitVersion}"
}

最佳答案

以下示例代码对我有用。

主要应用

package app;

import org.springframework.boot.SpringApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.util.Assert;

import javax.sql.DataSource;

public class Application {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(Config.class);
        DataSource dataSource = context.getBean("dataSource", DataSource.class);
        Assert.notNull(dataSource);
    }

}

Spring Java 配置

package app;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.*;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import javax.sql.DataSource;

@Configuration
@EnableAutoConfiguration
@EnableJpaRepositories
@ComponentScan
@ImportResource("classpath:config.xml")
public class Config {

    @Autowired
    private DataSource dataSource;

}

酒吧服务

package app.service;

import org.springframework.util.Assert;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;

public class BarService {

    private DataSource dataSource;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource);
    }
}

FooService

package app.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.Assert;

import javax.annotation.PostConstruct;
import javax.sql.DataSource;

@Service
public class FooService {

    @Autowired
    DataSource dataSource;

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource);
    }

}

config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="barService" class="app.service.BarService">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

关于spring - 如何在 XML 配置文件中使用 Spring Boot 自动配置的 bean？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25495629/