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Java list Properties


How to list Java Properties? Properties can be written to PrintWriter or PrintStream as we demonstrate in the example below.


java.util.Properties has two list() methods that write to different targets:

  • void list(PrintStream out)
    Prints all properties to given output stream.
  • void list(PrintWriter out)
    Prints all properties to given writer.

In the following example we create a new Properties object and fill with two properties. Then we print them using list(PrintStream) and passing System.out as our target:


import java.util.Properties;

public class PropertiesList {

    public static void main(String[] args) {
        Properties props = new Properties();
        props.setProperty("connectionTime", "1200");
        props.setProperty("maxThreads", "50");


As you can see, when defining property, both key and value are of String type.

Running the code produces the following output:

-- listing properties --
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