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Which of the following is a valid method to execute a stored procedure using JDBC?

  • CallableStatement.execute() with a procedure
  • executeQuery() with a stored procedure call
  • executeStoredProc()
  • executeUpdate() with a stored procedure call
To execute a stored procedure using JDBC, you typically use the CallableStatement interface and its execute() method with a procedure call. The other options (executeStoredProc(), executeQuery() with a stored procedure call, and executeUpdate() with a stored procedure call) are not standard methods for executing stored procedures in JDBC.
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You need to perform different actions on each element of a heterogeneous list (i.e., containing different types of objects). How would you implement the loop to handle different types and perform type-specific actions?

  • Use a custom iterator with type-specific handlers.
  • Use a for-each loop with instanceof checks.
  • Use a series of if statements to check each element's type.
  • Use a switch statement inside a for loop.
To handle different types in a heterogeneous list, you can use a for-each loop and check each element's type using the instanceof operator. This approach allows you to perform type-specific actions. The other options may not be as flexible or efficient for this task.
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Imagine you are developing a multi-threaded application for a bank. How would you ensure that when multiple threads are trying to update the same account, the account data remains consistent?

  • Employing optimistic locking techniques such as versioning, where each thread checks a version number before updating the account.
  • Implementing thread-safe data structures like ConcurrentHashMap to store account information.
  • Using synchronized methods or blocks to lock access to the account data when it's being updated.
  • Utilizing atomic operations provided by classes like AtomicInteger to ensure atomic updates of account data.
In a multi-threaded bank application, consistency can be achieved by using synchronized methods or blocks to ensure that only one thread can access and update the account data at a time. This prevents race conditions and data corruption. Other options, like using thread-safe data structures or atomic operations, can help with performance but may not guarantee consistency in complex scenarios. Optimistic locking with versioning can also be used to handle concurrent updates.
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Which of the following classes is used to create a button in JavaFX?

  • Button
  • CheckBox
  • Label
  • TextField
In JavaFX, the Button class is used to create a button. Buttons are interactive elements in a graphical user interface, and you can use the Button class to create them and add event handlers. The other classes mentioned are used for different purposes.
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To specify a repeating behavior in an animation, ______ method is used in JavaFX.

  • cycleAnimation()
  • repeatAnimation()
  • setCycleCount()
  • setRepeatCount()
In JavaFX, the setCycleCount() method is used to specify the number of times an animation should repeat. By setting the cycle count to a specific value, you can control how many times the animation should loop or repeat, creating repeating behaviors in your animations.
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Which of the following classes is mainly used to establish a connection to the database in JDBC?

  • java.sql.Connection
  • java.sql.DriverManager
  • java.sql.ResultSet
  • java.sql.Statement
The java.sql.DriverManager class in JDBC is primarily used for establishing database connections. It provides methods like getConnection to create connections to a database server. The other classes mentioned (Connection, Statement, and ResultSet) are used after the connection is established for various database operations.
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How can transactions be managed in JDBC to ensure data integrity?

  • By using Connection.setAutoCommit(false) and manually committing transactions using Connection.commit()
  • By using Connection.setAutoCommit(true) and allowing transactions to automatically commit on every SQL statement execution
  • By using Connection.setReadOnly(true) to prevent any data modification, thus ensuring data integrity
  • By using Connection.setTransactionIsolation() to set the desired isolation level, ensuring data consistency
In JDBC, transactions can be managed by setting auto-commit to false using Connection.setAutoCommit(false). This allows you to manually commit transactions using Connection.commit(). This approach ensures data integrity by allowing you to group multiple SQL statements into a single transaction and ensuring that they are either all executed or none at all. Setting auto-commit to true (option 2) will not provide the same level of control over transactions. Options 3 and 4 are unrelated to managing transactions in this context.
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Which of the following methods in the Stream API can change the type of the elements in a stream?

  • collect()
  • filter()
  • forEach()
  • map()
The map() method in the Stream API is used to transform elements in a stream. It takes a function as an argument and applies that function to each element in the stream, producing a new stream with the transformed elements. This can change the type of elements in the stream if the mapping function converts them to a different type. The other methods listed do not change the type of elements in the stream.
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In a scenario where you are designing a system that will store and manipulate confidential data (like passwords) which will be stored in the form of strings, how would you ensure that this sensitive data is not prone to security issues related to string handling?

  • Use String and encrypt it
  • Use String and mark it as 'final'
  • Use StringBuilder and set 'secure' flag
  • Use char[] to store passwords
To enhance security for sensitive data like passwords, you should use a char[] to store passwords instead of a String. This is because String objects are immutable and linger in memory, making them vulnerable to security risks. char[] can be overwritten, and you can zero it out after use. The other options do not provide similar security benefits.
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________ is an interface providing thread safety without introducing concurrency overhead for each individual read/write operation.

  • ConcurrentHashMap
  • ConcurrentHashSet
  • ConcurrentMap
  • SynchronizedMap
In Java, the ConcurrentMap interface provides thread safety without introducing excessive concurrency overhead for each read/write operation. It allows multiple threads to read and write concurrently while maintaining data integrity. Other options, like SynchronizedMap and ConcurrentHashSet, have different characteristics in terms of thread safety and performance.
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