Properties file for configuration in Selenium Java

Introduction

A properties file helps keep settings like URLs and usernames outside your test code. This makes tests easier to update and reuse.

When you want to change the website URL without changing the test code.

When you need to store login credentials safely and separately.

When running tests on different environments like dev, test, and production.

When multiple testers share the same test scripts but need different settings.

When you want to avoid hardcoding values inside your Selenium tests.

Syntax

Selenium Java

Properties prop = new Properties();
FileInputStream fis = new FileInputStream("config.properties");
prop.load(fis);
String url = prop.getProperty("url");
fis.close();

The properties file is a simple text file with key=value pairs.

Use getProperty to read values by their keys.

Examples

This is how the properties file looks. Each line has a key and a value separated by '='.

Selenium Java

# config.properties
url=https://example.com
username=testuser
password=pass123

This Java code loads the properties file and prints the username value.

Selenium Java

Properties prop = new Properties();
try (FileInputStream fis = new FileInputStream("config.properties")) {
    prop.load(fis);
    String username = prop.getProperty("username");
    System.out.println(username);
}

Sample Program

This program reads the config.properties file and prints the stored URL, username, and password.

Selenium Java

import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

public class ConfigTest {
    public static void main(String[] args) {
        Properties prop = new Properties();
        try (FileInputStream fis = new FileInputStream("config.properties")) {
            prop.load(fis);
            String url = prop.getProperty("url");
            String username = prop.getProperty("username");
            String password = prop.getProperty("password");
            System.out.println("URL: " + url);
            System.out.println("Username: " + username);
            System.out.println("Password: " + password);
        } catch (IOException e) {
            System.out.println("Failed to load properties file.");
        }
    }
}

Important Notes

Always close the FileInputStream to avoid resource leaks. Using try-with-resources is best.

Keep sensitive data like passwords secure and avoid committing them to public repositories.

Use meaningful keys in the properties file for easy understanding.

Summary

Properties files store configuration outside test code.

Use Java's Properties class to load and read these files.

This approach makes tests flexible and easier to maintain.

Practice

1. What is the main purpose of using a .properties file in Selenium Java tests?

easy

A. To compile Java source files automatically

B. To write the test cases in a different programming language

C. To store configuration data like URLs and credentials outside the test code

D. To store screenshots taken during test execution

Solution

1. Step 1: Understand the role of properties files

   Properties files are used to keep configuration data separate from code, such as URLs, usernames, and passwords.

2. Step 2: Identify the correct purpose in Selenium tests

   Using properties files makes tests flexible and easier to maintain by avoiding hard-coded values.

3. Final Answer:

   To store configuration data like URLs and credentials outside the test code -> Option C

4. Quick Check:

   Properties file = external config storage [OK]

Hint: Properties files hold config, not code or screenshots [OK]

Common Mistakes:

• Thinking properties files contain test scripts
• Confusing properties files with logs or reports
• Assuming properties files compile code

2. Which Java class is commonly used to load a .properties file in Selenium tests?

easy

A. Properties

B. FileReader

C. BufferedReader

D. FileInputStream

Solution

1. Step 1: Identify the class for properties handling

   The Properties class in Java is designed to load and read key-value pairs from .properties files.

2. Step 2: Differentiate from other classes

   While FileReader and FileInputStream help read files, Properties specifically loads and manages properties data.

3. Final Answer:

   Properties -> Option A

4. Quick Check:

   Java Properties class loads config files [OK]

Hint: Use Properties class to load .properties files [OK]

Common Mistakes:

• Using FileReader alone without Properties
• Confusing BufferedReader with Properties
• Trying to load properties without Properties class

3. Given the following code snippet, what will be the output if the config.properties file contains url=https://example.com?

Properties prop = new Properties();
FileInputStream fis = new FileInputStream("config.properties");
prop.load(fis);
System.out.println(prop.getProperty("url"));

medium

A. null

B. https://example.com

C. url=https://example.com

D. FileNotFoundException

Solution

1. Step 1: Load properties from file

   The Properties object loads key-value pairs from the file using load().

2. Step 2: Retrieve the value for key 'url'

   Calling getProperty("url") returns the value associated with 'url', which is 'https://example.com'.

3. Final Answer:

   https://example.com -> Option B

4. Quick Check:

   getProperty('url') = 'https://example.com' [OK]

Hint: getProperty(key) returns the value for that key [OK]

Common Mistakes:

• Expecting the whole line instead of just the value
• Confusing key with value in output
• Not loading the file before getting property

4. Identify the error in the following code snippet that tries to load a properties file:

Properties prop = new Properties();
FileInputStream fis = new FileInputStream("config.properties");
prop.load();
System.out.println(prop.getProperty("browser"));

medium

A. Missing argument in prop.load() method

B. FileInputStream path is incorrect

C. Properties object not instantiated

D. getProperty method is misspelled

Solution

1. Step 1: Check method usage for loading properties

   The load() method requires an InputStream argument, but here it is called without any argument.

2. Step 2: Verify other parts of the code

   The FileInputStream is correctly created, Properties is instantiated, and getProperty is spelled correctly.

3. Final Answer:

   Missing argument in prop.load() method -> Option A

4. Quick Check:

   load() needs InputStream argument [OK]

Hint: Always pass InputStream to load() method [OK]

Common Mistakes:

• Calling load() without argument
• Assuming load() reads file automatically
• Ignoring exceptions from FileInputStream

5. You want to switch browsers in your Selenium tests by changing only the browser value in a config.properties file. Which approach correctly reads this value and uses it to launch Chrome or Firefox browsers?

hard

A. Use getProperty('browser') but always launch ChromeDriver regardless of value

B. Hardcode browser choice in test code and ignore properties file

C. Load properties but never read 'browser' key, just launch FirefoxDriver

D. Load properties, get 'browser' value, then use if-else to create ChromeDriver or FirefoxDriver accordingly

Solution

1. Step 1: Load the properties file and read the 'browser' key

   Use Properties class to load the file and get the value of 'browser' key.

2. Step 2: Use conditional logic to launch the correct browser driver

   If the value is 'chrome', create a ChromeDriver instance; if 'firefox', create a FirefoxDriver instance.

3. Final Answer:

   Load properties, get 'browser' value, then use if-else to create ChromeDriver or FirefoxDriver accordingly -> Option D

4. Quick Check:

   Config-driven browser choice = if-else on getProperty('browser') [OK]

Hint: Use if-else on property value to pick browser driver [OK]

Common Mistakes:

• Ignoring properties file and hardcoding browser
• Not using conditional logic for browser selection
• Loading properties but not reading the key