SpringMVC配置多个properties文件之通配符解析

Z时代
2024-01-10
分类：IT

SpringMVC配置多个properties文件之通配符

在springmvc中配置加载properties文件一般会在

xml文件中配置如下


 <context:property-placeholder location="classpath:resources/properties/zza.properties" 
        ignore-unresolvable="true" />

如果希望在项目中添加了一个新的模块，并且希望新的模块和之前项目相对独立，需要新添加一个properties文件的话，那么需要在xml配置文件中，再配置一份。比如：


<context:property-placeholder location="classpath:resources/properties/zza.properties" 
        ignore-unresolvable="true" /> 
        <context:property-placeholder location="classpath:resources/properties/weixin.properties" 
        ignore-unresolvable="true" />

这样做就太麻烦了，每次添加完properties文件还得在xml文件中添加。并且还必须把ignore-unresolvable属性设置为true。

解决方案是：利用通配符

具体如下：


    <context:property-placeholder   location="classpath*:resources/properties/*.properties" />

多个SpringMVC项目配置统一管理

来自于springCloud的统一配置思路

因公司项目分多个系统进行开发，而系统架构几乎完全一样，所以同样的配置文件会存在不同的系统中

当其中的某些配置需要修改时，就需要依次把所有系统中相关的配置都修改掉

纯耗时且没技术含量的体力活

所以借鉴SpringCloud的统一配置文件管理思想来对公司多个系统的配置文件也进行统一管理

1.首先是properties文件

针对诸如数据库连接等类似的共通信息，如果数据库信息发生变更则都需要修改，为了方便者直接在服务器上放置一个默认的连接配置

并发布到IIS等server上，通过http请求能够获取到

然后修改加载资源文件的配置文件如下：


<?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 class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>http://192.168.0.32:82/properties/jdbc.properties</value>
            </list>
        </property>
    </bean>
</beans>

PropertyPlaceholderConfigurer默认是支持http和file方式加载资源的

2.针对各类xml配置文件

项目中除了web.xml外，还有众多的xml

和propertie文件一样，也是相同的配置文件存在于不同的项目中，一改就要挨个改，烦

同理，将xml发布，并修改IIS设置，使其通过浏览器能访问

iis需要增加MIME类型 properties和xml为text/plain才能在浏览器访问

然后就可以在浏览器访问了

<context-param>

<param-name>contextConfigLocation</param-name>

<param-value>

http://192.168.0.32:82/springConfig/applicationContext-resource.xml,

http://192.168.0.32:82/springConfig/applicationContext-db.xml,

http://192.168.0.32:82/springConfig/applicationContext-redis.xml,

http://192.168.0.32:82/springConfig/applicationContext-redission.xml,

http://192.168.0.32:82/springConfig/applicationContext-service.xml,

http://192.168.0.32:82/springConfig/applicationContext-filter.xml

</param-value>

</context-param>


<servlet>
        <description>spring-mvc</description>
        <servlet-name>mvc</servlet-name>
         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>
                http://192.168.0.32:82/spring-mvc.xml
<!--                 classpath:spring-mvc.xml -->
            </param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

这样就可以直接启动了，启动时可以查看下面日志信息确定加载内容是正确的

最开始是修改为这样的


<context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
                    http://192.168.0.32:82/springConfig/applicationContext-*.xml
            </param-value>
    </context-param>

和classpath一样，但是很遗憾，解析不了统配费，找不到文件

java.io.FileNotFoundException: URL [http://192.168.0.32:82/springConfig/] cannot be resolved to absolute file path because it does not reside in the file system: http://192.168.0.32:82/springConfig/
    at org.springframework.util.ResourceUtils.getFile(ResourceUtils.java:215)
    at org.springframework.core.io.AbstractFileResolvingResource.getFile(AbstractFileResolvingResource.java:53)
    at org.springframework.core.io.UrlResource.getFile(UrlResource.java:213)
    at org.springframework.core.io.support.PathMatchingResourcePatternResolver.doFindPathMatchingFileResources(PathMatchingResourcePatternResolver.java:689)
    at org.springframework.web.context.support.ServletContextResourcePatternResolver.doFindPathMatchingFileResources(ServletContextResourcePatternResolver.java:92)
    at org.springframework.core.io.support.PathMatchingResourcePatternResolver.findPathMatchingResources(PathMatchingResourcePatternResolver.java:478)
    at org.springframework.core.io.support.PathMatchingResourcePatternResolver.getResources(PathMatchingResourcePatternResolver.java:293)

仔细看源码加载配置文件的源码 PathMatchingResourcePatternResolver中这段


@Override
    public Resource[] getResources(String locationPattern) throws IOException {
        Assert.notNull(locationPattern, "Location pattern must not be null");
        if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) {
            // a class path resource (multiple resources for same name possible)
            if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()))) {
                // a class path resource pattern
                return findPathMatchingResources(locationPattern);
            }
            else {
                // all class path resources with the given name
                return findAllClassPathResources(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()));
            }
        }
        else {
            // Generally only look for a pattern after a prefix here,
            // and on Tomcat only after the "*/" separator for its "war:" protocol.
            int prefixEnd = (locationPattern.startsWith("war:") ? locationPattern.indexOf("*/") + 1 :
                    locationPattern.indexOf(":") + 1);
            if (getPathMatcher().isPattern(locationPattern.substring(prefixEnd))) {
                // a file pattern
                return findPathMatchingResources(locationPattern);
            }
            else {
                // a single resource with the given name
                return new Resource[] {getResourceLoader().getResource(locationPattern)};
            }
        }
    }