Question

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

例如，如果我的类路径上有数据相关的库，Spring Boot将自动配置一个DataSource对象，我可以将其自动装入我自己的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配置文件中执行相同操作，我将获得异常。我通过在我的主配置类中添加@ImportResource("classpath:xmlconfig.xml")来引导XML配置文件。这是我所谈论的一个例子......内部xmlconfig.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">

    <!-- 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，上面将在运行Spring Boot应用程序时给出异常。我还尝试使用自动配置的ConnectionFactory（在类路径上使用ActiveMQ）和EntityManagerFactory使用Hibernate＆amp;类路径上的JPA，但这都不起作用。

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

这里我的主要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 Configuration尚未得到很好的支持，并且框架的核心是基于XML配置的，但是我想使用Spring在某些集成元素中引导自动配置的DataSource和ConnectionFactory bean。

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项目以获取演示代码：

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。

这里的大部分代码都说明了这一点：

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中

<?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>

的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}"
}

Answer 1

以下示例代码对我有用。

主要申请

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 Config

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;

}

BarService

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接口

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中

<?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>

Answer 2

我使用了你的autoconfig-test示例项目，并且能够让它工作。我在xml中找到的唯一问题如下......

我假设您要使用嵌入式代理。当我运行你的项目时，这就是自动配置的......

@Bean
public ConnectionFactory jmsConnectionFactory() {
    return this.properties.createConnectionFactory();
}

这将创建一个名为 jmsConnectionFactory 的bean，但是您的xml正在尝试连接名为 connectionFactory 的bean。将bean名称更改为 jmsConnectionFactory 修复了...

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

我不知道你为什么要使用xml，但它确实有效。

修改我还要补充说，如何使用spring jpa集成可能会有一些误解。尽管 EntityManagerFactory 的自动装配确实有效，但它确实不应该直接使用。您应按如下方式连接 EntityManager ...

@PersistenceContext private EntityManager entityManager

我知道它超出了这个问题的范围，但只是想我应该添加

如何在XML配置文件中使用Spring Boot自动配置的bean？

2 个答案: