disconf实践（三）基于XML的分布式配置文件管理，自动reload

上一篇介绍了基于xml的非自动reload的分布式配置文件管理，这一篇介绍自动reload的方式（基于disconf实践二）。

1. 修改RedisConfig.java

package org.springinaction.weather.config;

public class RedisConfig {

    private String host;

    private String port;

    public String getHost() {
        return host;
    }

    public String getPort() {
        return port;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public void setPort(String port) {
        this.port = port;
    }

}

2. 新增回调

package org.springinaction.weather.config.callback;

import org.springframework.stereotype.Component;

import com.baidu.disconf.client.common.annotations.DisconfUpdateService;
import com.baidu.disconf.client.common.update.IDisconfUpdate;

@Component
@DisconfUpdateService(confFileKeys = { "redis.properties" })
public class RedisConfigCallback implements IDisconfUpdate {

    @Override
    public void reload() throws Exception {
    }

}

3. 修改spring配置文件

<?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-4.3.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.3.xsd">

    <!-- 使用disconf必须添加以下配置 -->
    <bean id="disconfMgrBean" class="com.baidu.disconf.client.DisconfMgrBean"
        destroy-method="destroy">
        <property name="scanPackage" value="org.springinaction.weather.config" />
    </bean>
    <bean id="disconfMgrBean2" class="com.baidu.disconf.client.DisconfMgrBeanSecond"
        init-method="init" destroy-method="destroy">
    </bean>

    <!-- 使用托管方式的disconf配置(无代码侵入, 配置更改会自动reload) -->
    <bean id="configproperties_reloadable_disconf"
        class="com.baidu.disconf.client.addons.properties.ReloadablePropertiesFactoryBean">
        <property name="locations">
            <list>
                <value>redis.properties</value>
            </list>
        </property>
    </bean>

    <bean id="propertyConfigurer"
        class="com.baidu.disconf.client.addons.properties.ReloadingPropertyPlaceholderConfigurer">
        <property name="ignoreResourceNotFound" value="true" />
        <property name="ignoreUnresolvablePlaceholders" value="true" />
        <property name="propertiesArray">
            <list>
                <ref bean="configproperties_reloadable_disconf" />
            </list>
        </property>
    </bean>
    
    <bean id="redisConfig" class="org.springinaction.weather.config.RedisConfig">
        <property name="host" value="${redis.host}" />
        <property name="port" value="${redis.port}" />
    </bean>
</beans>

修改之后，在管理端修改redis.properties的配置信息时，应用会自动reload并修改相应的参数。