spring無法讀取properties文件數據

只講述異常點，關於怎么配置文件，這里不做說明。

 

1. controller中無法讀取config.properties文件

controller中注入的@Value配置是從servlet-context.xml配置文件中獲取的；service中注入的@Value配置可以從applicationContext.xml中獲取的。所以，如果要在controller中注入屬性配置，需要在相應servlet文件中添加配置，同applicationContext.xml中一樣。

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list>
             <value>classpath:jdbc.properties</value>
            <value>classpath:config.properties</value>
         </list>
    </property>
    <property name="ignoreUnresolvablePlaceholders" value="true"/>
</bean>

 

2.service中無法讀取config.properties文件

查看配置文件是否有多個。如果配置的路徑是classpath:config.properties, 鼠標點擊文件。如果顯示”multiple implementations”, 表示有多個文件，查看其他的文件中是否有需要的配置項，沒有的話，很可能就是加載了其他文件的配置項。這時，將路徑改為classpath*:config.properties即可。

<context:property-placeholder
      ignore-unresolvable="true" location="classpath:/jdbc.properties, classpath*:/config.properties"/>

 查看日志，發現：

[2017-01-05 16:45:02 INFO ] [main] (org.springframework.context.support.PropertySourcesPlaceholderConfigurer:?) - Loading properties file from URL [jar:file:/home/admin/creative-task/lib/xxxx-common-1.5.7.jar!/config.properties]
[2017-01-05 16:45:02 INFO ] [main] (org.springframework.context.support.PropertySourcesPlaceholderConfigurer:?) - Loading properties file from URL [file:/home/admin/creative-task/conf/config.properties]

 加載了兩個config.properties文件。

 

3.關於診斷：

1）首先確認是否正確加載了配置文件。查看日志：

正常日志如下：

[2017-01-05 16:45:02 INFO ] [main] (org.springframework.context.support.PropertySourcesPlaceholderConfigurer:?) - Loading properties file from URL [file:/home/admin/creative-task/conf/config.properties]

 異常日志如下：

[2017-01-05 16:39:39 ERROR] [main] (Main:22) - Could not load properties; nested exception is java.io.FileNotFoundException: class path resource [config.properties] cannot be opened because it does not exist
org.springframework.beans.factory.BeanInitializationException: Could not load properties; nested exception is java.io.FileNotFoundException: class path resource [config.properties] cannot be opened because it does not exist 

如果文件沒有加載，則查看路徑是否匹配等。

 

2）如果文件加載ok，查看配置屬性是否正確加載。

查看tomcat啟動的debug日志：

正常日志如下：

[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [environmentProperties]
[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [systemProperties]
[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [systemEnvironment]
[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Could not find key 'adx.id' in any property source. Returning [null]
[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [localProperties]
[2017-01-05 16:45:04 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Found key 'adx.id' in [localProperties] with type [String] and value '1'

異常日志如下：

[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [environmentProperties]
[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [systemProperties]
[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [systemEnvironment]
[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Could not find key 'adx.id' in any property source. Returning [null]
[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Searching for key 'adx.id' in [localProperties]
[2017-01-05 16:34:01 DEBUG] [main] (org.springframework.core.env.PropertySourcesPropertyResolver:?) - Could not find key 'adx.id' in any property source. Returning [null]

如果配置屬性沒有正確加載，查看屬性配置的key是否正確。