J2EE Web Development and JDBC Fundamentals

Data Definition Language (DDL) commands define or modify database structures like tables, indexes, and schemas. CREATE is a DDL command used to create database objects. INSERT, UPDATE, and DELETE are Data Manipulation Language (DML) commands that manipulate the data within those structures.

PreparedStatement is specifically designed to execute parameterized queries safely and efficiently. It precompiles the SQL statement with placeholders (?) and allows setting parameters separately, preventing SQL injection. Regular Statement doesn't support parameterized queries. CallableStatement is for stored procedures.

The core JDBC API is in the java.sql package, containing interfaces like Connection, Statement, and ResultSet. The javax.sql package provides extended JDBC features like DataSource and connection pooling. Options with 'java.jdbc' are incorrect - the package structure is java.sql, not java.jdbc.

The executeUpdate method in JDBC returns an integer representing the number of rows affected by the SQL operation (INSERT, UPDATE, DELETE). It doesn't return the actual row data - just a count. For SELECT queries, you'd use executeQuery which returns a ResultSet.

To manage transactions manually in JDBC, auto-commit must be set to false before running transaction statements. The assertion that auto-commit must be turned off after the transaction is false, as by that point the individual operations would have already committed automatically.

Local variables in Java must be initialized before use. The code declares 'int x' in doPlay() but doesn't assign it a value before using '++x'. This causes a compile-time error. The instance variable 'x=5' is shadowed by the local declaration and is not accessed.

Integer.parseInt throws NumberFormatException when the string cannot be parsed as a valid integer. The string 'one' contains letters, not digits, so parsing fails. ClassCastException is for incompatible type conversions, and IllegalStateException is for invalid state timing.

JavaBeans getter methods follow the pattern 'getXxx()' where Xxx is the property name with the first letter capitalized. 'getCust' correctly follows this convention. 'addSize' and 'deleteRep' don't start with 'get' or 'is', and 'putDimensions' starts with 'put' which isn't a standard accessor prefix.

JSP pages are translated into servlets with specific lifecycle methods. jspInit() is called once when the JSP is initialized, _jspService() handles each request (equivalent to service()), and jspDestroy() is called before removal. The servlet methods init(), service(), destroy() are the underlying servlet equivalents, not the JSP-specific names.

JSP translation is the first phase in the JSP lifecycle where the JSP container parses the JSP file and translates it into a Java Servlet source file (.java). This generated servlet is then compiled and executed to handle requests and generate dynamic HTML output.

J2EE (Java 2 Enterprise Edition) applications support various types of clients. Web browsers access applications via HTTP/HTML, Applets run in a browser environment using JVM, and Wireless clients interact through lightweight protocols (like WAP). Therefore, all options represent valid J2EE client types.

JSP supports Java code through scriptlets (<% ... %>) and expressions (<%= ... %>). You can write pure Java code directly within these tags. However, best practices recommend minimizing scriptlets in favor of JSTL and custom tags for better separation of concerns.

In the Java Servlet API, all HTTP-specific servlets extend javax.servlet.http.HttpServlet. This class provides specialized methods like doGet(), doPost(), etc. for handling HTTP requests. While you could technically extend GenericServlet, HTTP servlets always extend HttpServlet for HTTP protocol support.

JSP pages are translated to servlets only ONCE - the first time they are accessed or when the web container starts. The generated servlet is then compiled and cached. Subsequent requests execute the same compiled servlet without retranslation. Only if the JSP source changes will it be retranslated.

JSP pages can include both JSP pages AND HTML pages using directives like jsp:include or <%@ include %>. The statement claims inclusion is restricted to JSP only, which is incorrect. Therefore the answer is False.

In JSP/Servlet technology, there are exactly four scopes: page (default), request, session, and application (context). Option C correctly lists all four available scopes.

JSP provides nine implicit objects including request, response, session, application (ServletContext), out, pageContext, page, config, and exception. Option C lists four of the most commonly used ones - while not exhaustive, it's the correct choice among the given options.

GET method submits data as part of the URL (visible in browser history/logs), making it insecure for sensitive data. POST sends data in the request body, hiding it from the URL. Also, GET has URL length limitations (typically 2048 characters), while POST does not.

When a JSP page is first requested, the container translates it into a servlet class and creates an instance. This servlet instance handles subsequent requests. The statement correctly describes this JSP-to-servlet translation process.

A single servlet instance typically handles multiple concurrent requests using a thread-per-request model. The container creates a thread for each request, all executing the same servlet instance's service() method. This makes servlets inherently multi-threaded.