What is HttpSession in Java?
HttpSession is an interface in the Java servlet technology that is used to track the user interaction with a web application across multiple requests or pages. It stores information in the form of key-value pairs that is associated with a particular user. HttpSession allows the application to maintain state for that user, thus persisting the data for the duration of the session. By using HttpSession, the application can track what users do within an application and store information about them like their preferences, login information, and activities.
For example, the following code draws a rectangle on the canvas:
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.fillStyle = "#FF0000";
ctx.fillRect(0, 0, 150, 75);
1. SyntaxError: Unexpected end of input
2. Uncaught ReferenceError
3. Uncaught TypeError
4. Undefined variable
5. Uncaught SyntaxError
6. Wrong number of arguments
7. Unexpected ')'
8. Cannot read property of 'x'
9. 'x' is not a function
10. Missing semicolon
What is debug debugging in Java?
Debugging in Java is the process of identifying and fixing errors in a given program. It is typically done by setting breakpoints and inspecting the values of variables to find the source of the bug. Debugging also involves checking syntax errors, memory leaks, and other common programming mistakes.
1. Make sure you have the correct versions of Selenium and the web browser driver installed.
2. Use explicit waits instead of implicit waits when waiting for elements to appear.
3. Use the latest version of the Selenium WebDriver.
4. Use the latest version of the web browser driver for the specific browser you are using.
5. Don’t use deprecated Selenium commands.
6. Organize test script flows for better readability and maintainable tests.
7. Follow atomic testing methodology.
8. Avoid using hard-coded wait times of any kind.
9. Utilize organized data sets for each test case.
10. Take advantage of reporting tools to have test evidence.
11. Utilize objects such as selectors, automated test frameworks and other utility modules.
12. Manage browser and WebDriver settings correctly.
13. Avoid browser dependency in the test scripts.
14. Make sure the element you are trying to interact with is visible on the page.
Global variables are variables that are available throughout the entire script and remain active in memory until the document is destroyed or the page is unloaded. A local variable, on the other hand, is a variable that is declared and used inside a specific function and is only accessible within that function. Local variables only exist while the function is running and are destroyed once the function has completed execution.
5. Increased Engagement: Customized form elements can encourage user engagement and help keep users on your website.
What is a thread in Java?
In Java, a thread is a concurrent process that allows multiple independent tasks to run simultaneously. A thread has its own call stack, program counter, and local variables. Threads may share memory and other resources, making them potentially more efficient than multiple processes. Threads can be used to process tasks in the background, allowing the main program to run without interruption.
What are interfaces in Java?
Interfaces in Java are abstract classes that have no instance variables, no constructors, and are composed only of methods, constants, and default methods. They provide a common set of methods that can be implemented by any class that implements the interface. Interfaces allow for a level of abstraction and create a contract between two or more objects.
How to install JavaFX in Eclipse?
1. Open Eclipse.
2. Select Help > Install New Software.
3. Select the Add button.
4. In the Add Repository window, select the Archive button and locate the JavaFX-SDK you have downloaded.
5. Select JavaFX-SDK and select the Next button.
6. Follow the prompts to complete the installation.
7. Restart Eclipse when prompted.
8. After restarting, check if JavaFX is installed correctly:
a. In the Eclipse main menu, select Window > Show View > Other.
b. In the Show View dialog, select Java and then JavaFX Scripts.
c. Select the OK button.
9. The JavaFX Scripts view should open, which means installation was successful.