Q1. What is JdbcTemplate?
JdbcTemplate is a Spring class that simplifies JDBC operations. It handles resource management (opening/closing connections) and exception handling, reducing boilerplate code. It provides methods for executing queries, updates, and batch operations.
Q2. How do you configure JdbcTemplate?
Define a DataSource bean and then JdbcTemplate bean, injecting the DataSource. Example:
@Bean
public JdbcTemplate jdbcTemplate(DataSource dataSource) {
return new JdbcTemplate(dataSource);
}
Q3. How do you query for a single object using JdbcTemplate?
Use queryForObject with a RowMapper. Example:
String sql = "SELECT * FROM users WHERE id = ?";
User user = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), id);
Q4. How do you perform an update using JdbcTemplate?
Use update method. Example:
String sql = "UPDATE users SET name = ? WHERE id = ?";
jdbcTemplate.update(sql, name, id);
Q5. What is RowMapper?
RowMapper is an interface to map each row of a ResultSet to an object. You implement mapRow method. BeanPropertyRowMapper is a convenient implementation that maps columns to bean properties by matching names.