How does the behavior of CachedThreadPool differ from that of FixedThreadPool in terms of thread creation and task management?
- CachedThreadPool creates a fixed number of threads and assigns one to each submitted task.
- CachedThreadPool creates new threads as needed and reuses previously constructed ones.
- FixedThreadPool creates a fixed number of threads and assigns one to each submitted task.
- FixedThreadPool creates new threads as needed and reuses previously constructed ones.
The behavior of CachedThreadPool differs from FixedThreadPool in that it dynamically creates new threads as needed and reuses previously constructed ones. This is suitable for tasks with variable workload. In contrast, FixedThreadPool maintains a fixed number of threads, each assigned to a task, making it ideal for tasks with a consistent workload.
Consider a scenario where you have to develop a JavaFX application that should adapt to different screen sizes. How would you approach the design and layout to ensure that the application is responsive and the UI adjusts dynamically?
- Create separate layouts for each screen size and switch between them based on the detected screen size.
- Set fixed pixel sizes for all UI elements to ensure consistent appearance across different screen sizes.
- Use JavaFX layout containers like VBox and HBox along with percentage-based sizing and responsive design principles.
- Use absolute positioning for UI elements to maintain precise control over their placement.
To create a responsive JavaFX application, you should use layout containers like VBox and HBox and design with percentage-based sizing to allow elements to adjust dynamically. Responsive design principles are essential for accommodating various screen sizes. Fixed pixel sizes, separate layouts, and absolute positioning are not recommended for achieving responsiveness.
The ________ interface of the JDBC API provides cursor support, which allows forward and backward navigation through the result set.
- Connection
- ResultSet
- ResultSetMetaData
- Statement
The ResultSet interface in the JDBC API provides cursor support, allowing you to navigate through the result set of a database query. You can move forward and backward, retrieve data, and perform various operations on the result set. The other options do not provide cursor support.
The ________ reference data type in Java is immutable and stores a sequence of characters.
- String
- StringBuilder
- List
- Array
The String class in Java is an immutable reference data type that stores a sequence of characters. Being immutable means that once a String object is created, its content cannot be changed. Understanding the immutability of strings is crucial for efficient string manipulation in Java.
When would you prefer byte streams over character streams while performing I/O operations in Java?
- When dealing with binary data and non-text files, such as images or audio.
- When working with XML or HTML files that contain text and tags.
- When you need to perform text-based operations, like reading and writing characters.
- When you want to handle file I/O in a platform-independent manner.
Byte streams are suitable for reading and writing binary data, while character streams are used for handling text data. Byte streams are ideal for handling non-text files, like images or audio, where individual bytes matter. Character streams are used for text files and automatically handle character encoding.
A ______ block can be used to define customized serialization logic.
- finalization
- synchronized
- try-catch
- writeObject
In Java, the writeObject block is used to define customized serialization logic for an object. It allows you to control how an object is serialized when it's written to an output stream. The other options are not used for custom serialization logic.
The method ________ is used to remove all the mappings from a Map.
- clear()
- eraseAll()
- removeAll()
- removeMappings()
In Java, the clear() method is used to remove all the mappings from a Map. It does not remove the map itself but makes it empty, removing all key-value pairs. The other options do not perform this specific function.
Deadlock occurs when two or more threads are blocked forever, each waiting for the other to ________.
- acquire
- complete
- join
- release
Deadlock in multithreading occurs when two or more threads are waiting for resources acquired by each other. They cannot proceed as they are both holding resources the other needs, resulting in a deadlock situation.
What is the maximum number of interfaces a Java class can implement?
- 1
- 2 or more
- 3 or more
- Unlimited
A Java class can implement an unlimited number of interfaces. This allows for multiple inheritance of method signatures, where the class must provide implementations for all the methods declared in the interfaces it implements.
The method ________ is used to send HTTP GET request without parameters.
- doGet()
- executeGET()
- get()
- sendGET()
In Java, to send an HTTP GET request without parameters, you typically use the sendGET() method. This method is commonly used in HTTP client libraries to initiate a GET request to a specified URL. The other options are not standard methods for this purpose.