The InetAddress class provides methods to get the IP address of a local computer by using method ________.
- getHostAddress()
- getIPAddress()
- getLocalAddress()
- getLocalHost()
In Java, you can obtain the IP address of the local computer using the getLocalHost() method of the InetAddress class. It returns an InetAddress object representing the local host's IP address. The other options are not used for this purpose.
How can you read an 8-bit byte from a file using byte streams in Java?
- BufferedReader
- FileReader
- FileReader
- InputStream
To read an 8-bit byte from a file using byte streams in Java, you should use the InputStream class. Byte streams are designed to work with binary data, and InputStream is the parent class for all byte input streams. FileReader and BufferedReader are used for character-based reading, not for reading raw bytes.
Which data type would be suitable to store a character value in Java?
- byte
- char
- double
- float
In Java, the char data type is used to store a single character. It can hold any character, including letters, numbers, and special symbols.
Consider a scenario where an application retrieves a large amount of data from a database and displays it in a UI paginated form. How would you efficiently manage and optimize data retrieval and display using JDBC?
- Implementing client-side caching of database results to improve data retrieval speed for pagination.
- Loading all data into memory and applying pagination through custom code to limit the data displayed in the UI.
- Retrieving all data at once and performing pagination on the client side using Java collections.
- Using JDBC ResultSet's pagination features, like setFetchSize, to fetch data in smaller chunks from the database.
When dealing with large data sets, it's essential to retrieve and display data efficiently. JDBC provides features like setFetchSize to fetch data in smaller portions, reducing memory usage and improving performance. Retrieving all data at once can lead to memory issues. Client-side caching can help, but it may not be suitable for very large datasets. Understanding these JDBC features is crucial for optimization.
Which method is used to check if there are more lines of text to read from a BufferedReader object?
- canReadMore()
- hasMoreLines()
- hasNext()
- hasNextLine()
The BufferedReader class has a method called hasNextLine() that is used to check if there are more lines of text to read from the BufferedReader object. It returns true if there are more lines and false if the end of the file has been reached. The other options do not represent the correct method for this purpose.
When using a single-thread executor, what happens if a submitted task throws an exception?
- The exception is caught, logged, and the executor continues to execute other tasks.
- The exception is ignored, and the executor continues to execute other tasks.
- The exception is propagated up the call stack to the caller of the submit() method.
- The thread running the task is terminated, and the executor replaces it with a new thread.
In a single-thread executor, when a submitted task throws an exception, it is caught and logged, but the executor continues to execute other tasks. The executor does not terminate due to an exception in a single task; it maintains the single thread for execution.
In Java, if a class implements an interface and does not provide implementations for all its methods, it must be declared as ________.
- Abstract Class
- Concrete Class
- Final Class
- Static Class
When a class in Java implements an interface but doesn't provide implementations for all the interface methods, it must be declared as an abstract class. This is because an abstract class can have unimplemented methods, while concrete classes need to provide implementations for all interface methods they inherit.
The keyword ________ is used to skip the rest of the current loop iteration.
- break
- continue
- exit
- return
In Java, the continue keyword is used to skip the rest of the current loop iteration and move to the next iteration. It is often used in loops like for and while when certain conditions are met, and you want to skip the current iteration and continue with the next one. The other options do not serve this purpose.
The relational operators are often used inside the ______ statement to produce boolean value.
- for
- if
- switch
- while
Relational operators (e.g., <, >, ==) are commonly used inside the "if" statement to create conditions that produce boolean (true/false) values based on comparisons.
What will happen if the DriverManager is unable to connect to the database using the provided URL?
- A compilation error will occur
- A runtime exception will be thrown
- An SQLException will be thrown
- It will silently retry to connect in the background
When the DriverManager in JDBC fails to connect to the database using the provided URL, it throws an SQLException. This exception should be handled in your code to gracefully manage the failure and take appropriate actions, such as logging the error or providing a user-friendly message.