What is ResultSetExtractor in spring?

ResultSetExtractor interface is a callback interface used by JdbcTemplate’s query methods. Implementations of this interface perform the actual work of extracting results from a ResultSet, but don’t need to worry about exception handling. SQLExceptions will be caught and handled by the calling JdbcTemplate.

Which of these is the JdbcTemplate callback interface described below it extracts values from each row of a ResultSet?

The RowCallbackHandler interface extracts values from each row of a ResultSet. The JdbcTemplate can be used within a DAO implementation via direct instantiation with a DataSource reference, or be configured in a Spring IOC container and given to DAOs as a bean reference.

Is JdbcTemplate thread safe?

Instances of the JdbcTemplate class are threadsafe once configured. This is important because it means that you can configure a single instance of a JdbcTemplate and then safely inject this shared reference into multiple DAOs (or repositories).

What is the use of ResultSet object in JDBC?

A ResultSet object maintains a cursor that points to the current row in the result set. The term “result set” refers to the row and column data contained in a ResultSet object. Navigational methods − Used to move the cursor around.

What is Spring JdbcTemplate?

Spring JdbcTemplate is a powerful mechanism to connect to the database and execute SQL queries. It internally uses JDBC api, but eliminates a lot of problems of JDBC API.

What is datasource in Spring?

A DataSource is a factory for connections to the physical databases. It is an alternative to the DriverManager facility. A datasource uses a URL along with username/password credentials to establish the database connection. In Java, a datasource implements the javax. sql.

How do I write a JdbcTemplate query?

A basic query example using RowMapper with no arguments.

  1. @Autowired.
  2. private JdbcTemplate jdbcTemplate;
  3. @Test.
  4. @DisplayName(“find-all-users-test”)
  5. void findAllUsersTest() {
  6. String sql = “SELECT * FROM USER”;
  7. List users = jdbcTemplate. query(sql, new UserMapper());
  8. assertTrue(users. size() == 12);

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