Question

我需要在applicationContext.xml

中设置参数值接口IP地址

我从属性文件中读取此设置，并以这种方式使用它：

<bean id="hazelcastInterface" class="com.hazelcast.config.InterfacesConfig">
        <property name="interfaces">
            <list>
                <value>${interface.ip_address}</value>
            </list>
        </property>
        <property name="enabled" value="true" />
    </bean>

现在我需要从命令行参数中获取此值。我使用Apache Commons CLI解析器，解析参数并从中创建自己的bean commandLineConf并将其设置为ApplicationContext。

ExternalBeanReferneceFactoryBean.setInstance("commandLineConf", conf);
beanFactory.registerBeanDefinition(
    "commandLineConf",
    BeanDefinitionBuilder.rootBeanDefinition(
        ExternalBeanReferneceFactoryBean.class)
        .getBeanDefinition());

GenericApplicationContext rootAppContext = new GenericApplicationContext(
    beanFactory);
rootAppContext.refresh();

但我不知道如何在applicationContext.xml中从这个bean获取值。我尝试了很多方法，例如但它对我不起作用。

<bean id="hazelcastInterface" class="com.hazelcast.config.InterfacesConfig">
        <property name="interfaces">
            <list>
                <value>#{commandLineConf.ipAddress}</value>
            </list>
        </property>
        <property name="enabled" value="true" />
    </bean>

我做错了什么？

Answer 1

我用适当的类测试了你的xml应用程序上下文，我从这个主程序中获得了预期的ipAddress：

public static void main(String[] args) {

        CommandLineConf conf = new CommandLineConf();
        conf.setIpAddress("127.0.0.1");
        // create root beanFactory
        DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();

        // register bean definition for the command line
        ExternalBeanReferneceFactoryBean.setInstance("commandLineConf", conf);
        beanFactory.registerBeanDefinition(
            "commandLineConf",
            BeanDefinitionBuilder.rootBeanDefinition(
                ExternalBeanReferneceFactoryBean.class)
                .getBeanDefinition());

        GenericApplicationContext rootAppContext = new GenericApplicationContext(
            beanFactory);
        rootAppContext.refresh();

        // create the application context
        ApplicationContext appContext = new ClassPathXmlApplicationContext(new String[] { 
            "/applicationContext.xml"
        }, rootAppContext);

        InterfacesConfig hazelcastInterface = (InterfacesConfig)appContext.getBean("hazelcastInterface");
        System.out.println(hazelcastInterface.getInterfaces().get(0));

    }

所以你使用正确的语法来引用地址，即：＃{commandLineConf.ipAddress}

这让我觉得问题出在conf变量中。您的代码没有显示它是如何填充的，我怀疑缺少ipAddress。我无法确定，因为你没有在你的snipplet中包含解析参数。在开始构建spring上下文之前（例如通过打印它），确保confAddress中存在ipAddress。

我包含您可能需要的其余课程，以获得有效的代码：

InterfacesConfig.java

public class InterfacesConfig {
    private List<String>interfaces;
    private boolean enabled;

    public List<String> getInterfaces() {
        return interfaces;
    }

    public void setInterfaces(List<String> interfaces) {
        this.interfaces = interfaces;
    }
    public boolean isEnabled() {
        return enabled;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

}

CommandLineConf.java

public class CommandLineConf {
    private String ipAddress;
    public String getIpAddress() {
        return ipAddress;
    }

    public void setIpAddress(String ipAddress) {
        this.ipAddress = ipAddress;
    }
}

ExternalBeanReferneceFactoryBean.java

import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.config.AbstractFactoryBean;

public class ExternalBeanReferneceFactoryBean extends AbstractFactoryBean implements BeanNameAware {

    private static Map<String, Object> instances = new HashMap<String, Object>();
    private String beanName;

    /**
     * @param instance the instance to set
     */
    public static void setInstance(String beanName, Object instance) {
        instances.put(beanName, instance);
    }

    @Override
    protected Object createInstance() 
        throws Exception {
        return instances.get(beanName);
    }

    @Override
    public Class<?> getObjectType() {
        return instances.get(beanName).getClass();
    }

    @Override
    public void setBeanName(String name) {
        this.beanName = name;
    }

}

applicationContext.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"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<bean id="hazelcastInterface" class="com.hazelcast.config.InterfacesConfig">
        <property name="interfaces">
            <list>
                <value>#{commandLineConf.ipAddress}</value>
            </list>
        </property>
        <property name="enabled" value="true" />
    </bean>
</beans>

如何在applicationContext.xml中读取bean的值？

1 个答案: