TransactionTemplate vs JdbcTemplate

The Spring framework provides two means of programmatic transaction management:

1. Using the TransactionTemplate.

2. Using a PlatformTransactionManager implementation directly.

The above is de开发者_开发问答scribed here: http://static.springsource.org/spring/docs/2.0.8/reference/transaction.html

The Spring site hasnot mentioned JdbcTemplate here. As per my understanding JdbcTemplate also manages the transaction internally and this is all done in programme too.

So what's the basic difference between TransactionTemplate and JdbcTemplate?

JdbcTemplate is not a transaction manager. It's merely a helper class for native JDBC operations:

This is the central class in the JDBC core package. It simplifies the use of JDBC and helps to avoid common errors. It executes core JDBC workflow, leaving application code to provide SQL and extract results. This class executes SQL queries or updates, initiating iteration over ResultSets and catching JDBC exceptions and translating them to the generic, more informative exception hierarchy defined in the org.springframework.dao package.

TransactionTemplate by the way is also not a transaction manager, it's a

Template class that simplifies programmatic transaction demarcation and transaction exception handling.

The PlatformTransactionManager (and other subclasses of AbstractPlatformTransactionManager) is a transaction manager, as in it

• determines if there is an existing transaction;
• applies the appropriate propagation behavior;
• suspends and resumes transactions if necessary;
• checks the rollback-only flag on commit;
• applies the appropriate modification on rollback (actual rollback or setting rollback-only);
• triggers registered synchronization callbacks (if transaction synchronization is active).

So this class is responsible for the actual transaction handling, as opposed to the TransactionTemplate, which is to be used if you instead of declarative transaction handling you want to implement it programmetically. (see this blog, though quite outdated, you will see the difference between declarative and manual)

Quotes from Spring 3 Reference.

Note: Throughout the Spring Framework you will find other *Template classes as well: HibernateTemplate, JmsTemplate etc. They all follow the same pattern: template classes which radically reduce the amount of code you need to write, because all the so-called boilerplate code will be handled by them. Example (from here):

Without JdbcTemplate:

private DataSource dataSource;

public void setDataSource(DataSource dataSource) {
    this.dataSource = dataSource;
}

public void insert(Customer customer){

    String sql = "INSERT INTO CUSTOMER " +
            "(CUST_ID, NAME, AGE) VALUES (?, ?, ?)";
    Connection conn = null;

    try {
        conn = dataSource.getConnection();
        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setInt(1, customer.getCustId());
        ps.setString(2, customer.getName());
        ps.setInt(3, customer.getAge());
        ps.executeUpdate();
        ps.close();

    } catch (SQLException e) {
        throw new RuntimeException(e);

    } finally {
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {}
        }
    }
}

And with JdbcTemplate:

private DataSource dataSource;
private JdbcTemplate jdbcTemplate;

public void setDataSource(DataSource dataSource) {
    this.dataSource = dataSource;
}

public void insert(Customer customer){

    String sql = "INSERT INTO CUSTOMER " +
        "(CUST_ID, NAME, AGE) VALUES (?, ?, ?)";

    jdbcTemplate = new JdbcTemplate(dataSource);

    jdbcTemplate.update(sql, new Object[] { customer.getCustId(),
        customer.getName(),customer.getAge()  
    });

}