1. controller中無法讀取config.properties檔案

controller中注入的@Value配置是從servlet-context.xml配置檔案中獲取的；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檔案中新增配置，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檔案

檢視配置檔案是否有多個。如果配置的路徑是classpath:config.properties,滑鼠點選檔案。如果顯示”multiple implementations”,表示有多個檔案，檢視其他的檔案中是否有需要的配置項，沒有的話，很可能就是載入了其他檔案的配置項。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"/>

檢視日誌，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]

載入了兩個config.properties檔案。

3.關於診斷：

1）首先確認是否正確載入了配置檔案。檢視日誌：

正常日誌如下：

[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]

 異常日誌如下：

[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 

如果檔案沒有載入，則檢視路徑是否匹配等。

2）如果檔案載入ok，檢視配置屬性是否正確載入。

檢視tomcat啟動的debug日誌：

正常日誌如下：

[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'

異常日誌如下：

[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]

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