Question

我有这个基于xml的配置。但在我的项目中，我想使用基于java注释的配置。如何进行转换？

 <?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="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
        <property name="host" value="mail.csonth.gov.uk"/>
    </bean>

    <bean id="registrationService" class="com.foo.SimpleRegistrationService">
        <property name="mailSender" ref="mailSender"/>
        <property name="velocityEngine" ref="velocityEngine"/>
    </bean>

    <bean id="velocityEngine" class="org.springframework.ui.velocity.VelocityEngineFactoryBean">
        <property name="velocityProperties">
            <value>
                resource.loader=class
                class.resource.loader.class=org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
            </value>
        </property>
    </bean>

</beans>

Answer 1

创建一个使用@Configuration（org.springframework.context.annotation.Configuration）注释的类，并为XML文件中的每个bean声明在此类中创建@Bean（org.springframework.context.annotation.Bean）方法。

@Configuration
public class MyConfiguration {

    @Bean
    public JavaMailSenderImpl mailSender() {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost("mail.csonth.gov.uk");
        return mailSender;
    }

    @Bean
    public SimpleRegistrationService registrationService(JavaMailSenderImpl mailSender, VelocityEngineFactoryBean velocityEngine) {
        SimpleRegistrationService registrationService = new SimpleRegistrationService();
        registrationService.setMailSender(mailSender);
        registrationService.setVelocityEngine(velocityEngine); 
        return registrationService; 
    }

    @Bean
    public VelocityEngineFactoryBean velocityEngine() {
        VelocityEngineFactoryBean velocityEngine = new VelocityEngineFactoryBean();
        Properties velocityProperties = new Properties();
        velocityProperties.put("resource.loader", "class");
        velocityProperties.put("class.resource.loader.class", "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
        velocityEngine.setVelocityProperties(velocityProperties);
        return velocityEngine;
    }
}

此示例假定应用程序配置中的其他位置需要mailSender和velocityEngine bean，因为您提供的XML配置暗示了这一点。如果不是这种情况，即构造mailSender bean需要velocityEngine和registrationService bean仅那么您不需要声明{{ 1}}和mailSender()方法作为公共，您也不需要使用velocityEngine()进行注释。

您可以指示Spring通过

读取此配置类

组件扫描，例如@Bean
使用@ComponentScan("your.package.name")注册课程，例如
```
AnnotationConfigApplicationContext
```

Answer 2

@glitch的回答很有帮助，但我在下面的行中收到错误。

velocityEngine.setVelocityProperties("resource.loader=class", "class.resource.loader.class=org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");

我怎么解决这个问题。以下是完整的实施

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import com.vlclabs.adsops.service.SendEmailServiceImpl;
import org.springframework.ui.velocity.VelocityEngineFactoryBean;

import java.util.Properties;

@Configuration
public class EmailConfiguration {

    @Bean
    public JavaMailSenderImpl mailSender() {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost("mail.csonth.gov.uk");
        return mailSender;
    }

    @Bean
    public SendEmailServiceImpl registrationService(JavaMailSenderImpl mailSender, VelocityEngineFactoryBean velocityEngine) {
        SendEmailServiceImpl registrationService = new SendEmailServiceImpl();
        registrationService.setMailSender(mailSender);
        registrationService.setVelocityEngine(velocityEngine.getObject()); 
        return registrationService;
    }

    @Bean
    public VelocityEngineFactoryBean velocityEngine() {

        VelocityEngineFactoryBean velocityEngine = new VelocityEngineFactoryBean();
        Properties velocityProperties = new Properties();
        velocityProperties.put("resource.loader", "class");
        velocityProperties.put("class.resource.loader.class", "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
        velocityEngine.setVelocityProperties(velocityProperties);

        return velocityEngine;
    }
}

如何将spring bean集成从XML转换为基于Java注释的Config

2 个答案: