How to read from properties file?

Question

I want to read a line from properties file called jdbc.properties. It locate in src\\main\\webapp\\WEB-INF\\db\\jdbc.properties . What path should I use? This is my method:

Properties prop = new Properties();

        try {
            // load a properties file
            prop.load(new FileInputStream("jdbc.properties"));

            System.out.println(prop.getProperty("password"));

        } catch (IOException ex) {
            ex.printStackTrace();
        }

Answer 1

If you move your properties file to src/main/resources , assuming your project is managed by maven, then you could retrieve it by doing

Properties prop = new Properties();

try {
    // load a properties file
    prop.load(YourClass.class.getResourceAsStream("/jdbc.properties")); // note the leading /

    System.out.println(prop.getProperty("password"));

} catch (IOException ex) {
    ex.printStackTrace();
}

where YourClass is whatever class this code is in.

Maven places the class files of your compiled classes and all resources in src/main/resources in WEB-INF/classes where only your application can access them.

If you put the file in src/main/resources/someFolder , you'll need to access it from

prop.load(YourClass.class.getResourceAsStream("/someFolder/jdbcProperties"));

The path you provide to the above method is relative to the package of the class you are in, unless you specify a leading forward-slash, in which case it will be relative to the root of the classpath, ie classes folder.

Answer 2

You need to specify an absolute path to the FileInputStream . You can get the path by calling servletContext.getRealPath("/WEB-INF/db/jdbc.properties")

If you do not have the servletContext available (via .getServletContext() ), then you should pass it (or the absolute path to the root of the app) to the code above.

Answer 3

Is environment variable set for TOMCAT_HOME, if not set it up.

Now you can use

<tomcat_home>/webapps/<yourapp>/web-inf/db/jdbc.properties

To get value of environment variable use following code:

Map<String, String> env = System.getenv();

Cheers !!