How to use Java property files?

java properties
Click Upvote picture Click Upvote · Aug 23, 2009 · Viewed 303.9k times · Source

I have a list of key/value pairs of configuration values I want to store as Java property files, and later load and iterate through.

Questions:

  • Do I need to store the file in the same package as the class which will load them, or is there any specific location where it should be placed?
  • Does the file need to end in any specific extension or is .txt OK?
  • How can I load the file in the code
  • And how can I iterate through the values inside?

Answer

Zed picture Zed · Aug 23, 2009

You can pass an InputStream to the Property, so your file can pretty much be anywhere, and called anything.

Properties properties = new Properties();
try {
  properties.load(new FileInputStream("path/filename"));
} catch (IOException e) {
  ...
}

Iterate as:

for(String key : properties.stringPropertyNames()) {
  String value = properties.getProperty(key);
  System.out.println(key + " => " + value);
}

Related questions

Reading Properties file in Java

I have the following code trying to read a properties file: Properties prop = new Properties(); ClassLoader loader = Thread.currentThread().getContextClassLoader(); InputStream stream = loader.getResourceAsStream("myProp.properties"); prop.load(stream); I get an exception at the last line. Specifically: Exception in …

Read More
Java system properties and environment variables

What's the difference between system properties System.getProperties() and environment variables System.getenv() in a JVM?

Read More
java.util.MissingResourceException: Can't find bundle for base name 'property_file name', locale en_US

I am trying to create a utility class ReadPropertyUtil.java for reading data from property file. While my class is located under a util directory , my skyscrapper.properties file is placed in some other directory. But , when i try to …

Read More