[news.eclipse.platform.swt] How to visit properties file in the Eclipse-

[exquisitus <jefftymc@xxxxxxxxx>]

Hi,
    I have a preferences page in my Eclipse-plugin project and I want 
to save the info of the page to config.properties.
    The project structure is like this:

TestPlugin
|
|---src
|    |
|    com.test.plugin
|    |--xxx.java
|
|---JRE System Library
|---Plug-in Dependencies
|---icons
|
|---plugin.xml
|---config.properties

    I tried to use like this:

    Properties prop = new Properties();
    String absoluteUsrPath = 
Thread.currentThread().getContextClassLoader().getResource("").toString();
    int length = absoluteUsrPath.length();
    // delete "bin/"
    absoluteUsrPath.substring(0, length - 4) + "config.properties";
    InputStream is = new FileInputStream(absoluteUsrPath);
    prop.load(is);

    But it doesn't work. If it's a Java Project it do work but now it's 
a plugin-project and it will be used a jar file.
    How to read and write the properties file in the plugin develeopment?

Thanks in advance!