java调用properties中的配置

使用场景：使用dubbo服务，对应了dev，test，prod等环境的配置文件，如：filter-dev.properties,filter-test.properties,filter-prod.properties.不同的properties里面对于同一个变量需要有不同的配置，比如我设定了每日短信发送条数上线：sms.limit.count=20000

接手的是老代码，对应配置的调用有两种方式，
一种是在xml文件中声明一个对PropertyPlaceholderConfigurer的继承类PropertiesLoader

<bean id="propertyPlaceholderConfigurer" class="com.artist.common.utils.PropertiesLoader">
    <property name="location">
        <value>classpath:env/filter-${environment}.properties</value>
    </property>
</bean>
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package com.artist.common.utils;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Properties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;

public class PropertiesLoader extends PropertyPlaceholderConfigurer {
    private static Logger logger = LoggerFactory.getLogger(PropertiesLoader.class);
    private static Map<String, String> propertyMap;

    public PropertiesLoader() {
    }

    protected void processProperties(ConfigurableListableBeanFactory beanFactoryToProcess, Properties props) throws BeansException {
        super.processProperties(beanFactoryToProcess, props);
        propertyMap = new HashMap();
        Iterator var3 = props.keySet().iterator();

        while(var3.hasNext()) {
            Object key = var3.next();
            String keyStr = key.toString();
            String value = props.getProperty(keyStr);
            propertyMap.put(keyStr, value);
        }

    }

    public static String getValue(String key) {
        String systemProperty = System.getProperty(key);
        return systemProperty != null?systemProperty:(String)propertyMap.get(key);
    }

    public String getProperty(String key) {
        String value = getValue(key);
        if(value == null) {
            throw new NoSuchElementException();
        } else {
            return value;
        }
    }

    public String getProperty(String key, String defaultValue) {
        String value = getValue(key);
        return value != null?value:defaultValue;
    }

    public static Integer getInteger(String key) {
        String value = getValue(key);
        if(value == null) {
            throw new NoSuchElementException();
        } else {
            return Integer.valueOf(value);
        }
    }

    public static Integer getInteger(String key, Integer defaultValue) {
        String value = getValue(key);
        return value != null?Integer.valueOf(value):defaultValue;
    }

    public static Double getDouble(String key) {
        String value = getValue(key);
        if(value == null) {
            throw new NoSuchElementException();
        } else {
            return Double.valueOf(value);
        }
    }

    public static Double getDouble(String key, Integer defaultValue) {
        String value = getValue(key);
        return Double.valueOf(value != null?Double.valueOf(value).doubleValue():(double)defaultValue.intValue());
    }

    public static Boolean getBoolean(String key) {
        String value = getValue(key);
        if(value == null) {
            throw new NoSuchElementException();
        } else {
            return Boolean.valueOf(value);
        }
    }

    public static Boolean getBoolean(String key, boolean defaultValue) {
        String value = getValue(key);
        return Boolean.valueOf(value != null?Boolean.valueOf(value).booleanValue():defaultValue);
    }
}

java调用：private static String SMSLIMITCOUNT= PropertiesLoader.getValue("sms.limit.count");

一种是用spring的@Value 比如

@Value("${sms.limit.count}")
String smsLimitCount;

在xml配置文件中声明properties：

<context:property-placeholder location="classpath:config/application.properties,classpath:env/filter-${environment}.properties"/>

相比之下，第二种方法比较简单，只是之前写的人写法是这样的：

<context:property-placeholder location="classpath:config/application.properties"/>
<context:property-placeholder location="classpath:env/filter-${environment}.properties"/>

这种写法导致evn/filter-${enviroment}.properties里面的配置文件项在java中找不到，在xml配置文件里是可以的