如何阅读战争外放置的属性文件？ [英] How to read properties file placed outside war?

问题描述

这些天我正在开发一个Web应用程序。那只使用jsps和servlet。这是一个小应用程序。现在我已将所有DataSource详细信息放在DAO实用程序类中。我想将这些细节放在一个可以置于战争之外的属性文件中，这样根据环境我们可以改变这些值，而不会影响战争。我怎样才能实现这个目标？

I'm working on a web application these days. That uses only jsps and servlets. It's a small application. Right now I have placed all the DataSource details in DAO utility class. I want to place these details in a properties file that can be placed outside the war, so that depending on the environment we can change these values, without effecting the war. How can I achieve this?

推荐答案

我就是这样做的：

将以下内容添加到context.xml文件（conf文件夹，在tomcat安装目录中）。你可以改变名字属性;并在值中设置您拥有属性文件的文件夹的路径。

Add the following to context.xml file (conf folder, in tomcat installation dir). you may change the name attribute; and in value set the path of the folder where you have your properties files.

<Environment name="config" value="C:\Program files\my app\"  
         type="java.lang.String" override="false"/>

然后在你的util类中，你可以得到这样的文件:(在java：comp / env / config将'config'替换为您在context.xml中使用的name属性的值）

Then in your util class, you can get the file like this: (in "java:comp/env/config" replace 'config' with the value of the "name" attribute you used in context.xml)

String folderName = null;
Properties properties = new Properties();
try {
   InitialContext context = new InitialContext();
   folderName = (String) context.lookup("java:comp/env/config");
} catch (NamingException ex) {
   System.out.println("exception in jndi lookup");
}
if(folderName != null) {
   File configFile = new File(folderName + "yourfile.properties");
   try {
       InputStream is = new FileInputStream(configFile);
       properties.load(is);
   } catch(IOException ex) {
      System.out.println("exception loading properties file");
   }
}

希望这可以帮助您或其他任何人。

Hope this helps you or anyone else.

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