本文我们一起看看Spring Boot中 JdbcClient 和 JdbcTemplate 之间的差异。

以下内容使用的Java和Spring Boot版本为：

• Java 21
• Spring Boot 3.2.1

假设我们有一个ICustomerService接口：

public interface ICustomerService {
    
    List<Customer> getAllCustomer();

    Optional<Customer> getCustomerById(int id);

    void insert(Customer customer);

    void update(int id, Customer customer);
    
    void delete(int id);
}

其中，涵盖了我们常见的数据CRUD操作。

下面就来一起看看，分别使用 JDBC Client 和 JDBC Template 的实现。

初始化对比

JdbcTemplate的初始化：

private final JdbcTemplate jdbcTemplate;

public CustomerJdbcTemplateService(JdbcTemplate jdbcTemplate){
  this.jdbcTemplate = jdbcTemplate;
}

JdbcClient的初始化；

private final JdbcClient jdbcClient;

public CustomerJdbcClientService(JdbcClient jdbcClient){
  this.jdbcClient = jdbcClient;
}

增删改查的实现对比

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查询的实现对比

getAllCustomer查询返回集合数据的实现对比：

// jdbcTemplate实现
private final RowMapper<Customer> rowMapper = (rs, row)
     -> new Customer(rs.getInt("id"), rs.getString("name"), rs.getString("lastname"), rs.getDate("birthday"));

public List<Customer> getAllCustomer() {
  return jdbcTemplate.query("select id, name, lastname, birthday from customer", rowMapper);
}

// jdbcClient实现
public List<Customer> getAllCustomer(){
  return jdbcClient.sql("select id, name, lastname, birthday from customer").query(Customer.class).list();
}

getCustomerById查询返回单条数据的实现对比：

// jdbcTemplate实现
public Optional<Customer> getCustomerById(int id) {
  Customer customer = null;
  try {
    customer = jdbcTemplate.queryForObject("select id, name, lastname, birthday from customer where id = ?", rowMapper,  id );
  } catch (DataAccessException ex){
    LOG.error("Data not found. Id parameter: " + id, ex);
  }
  return Optional.ofNullable(customer);
}

// jdbcClient实现
public Optional<Customer> getCustomerById(int id){
  return jdbcClient.sql("select id, name, lastname, birthday from customer where id= :id")
                   .param("id", id)
                   .query(Customer.class)
                   .optional();
}

insert插入数据的实现对比

// jdbcTemplate实现
public void insert(Customer customer) {
  int inserted = jdbcTemplate.update("insert into customer (id, name, lastname, birthday) values (?,?,?,?)",
                 customer.id(), customer.name(), customer.lastname(),customer.birthday());
  Assert.state(inserted == 1 , "An exception error occurred while inserting customer");
}

// jdbcClient实现
public void insert(Customer customer){
  int inserted = jdbcClient.sql("insert into customer (id, name, lastname, birthday) values (?,?,?,?)")
                .params(List.of(customer.id(), customer.name(), customer.lastname(), customer.birthday()))
                .update();
  Assert.state(inserted == 1 , "An exception error occurred while inserting customer");
}

update更新数据的实现对比

// jdbcTemplate实现
public void update(int id, Customer customer) {
  int updated = jdbcTemplate.update("update customer set name = ?, lastname = ?, birthday = ? where id = ? ",
                customer.name(), customer.lastname(),customer.birthday(), id);
  Assert.state(updated == 1 , "An exception error occurred while updating customer");
}

// jdbcClient实现
public void update(int id, Customer customer){
  int updated = jdbcClient.sql("update customer set name = ?, lastname = ?, birthday = ? where id = ?")
                .params(List.of(customer.name(), customer.lastname(), customer.birthday(), id))
                .update();
  Assert.state(updated == 1, "An exception error occurred while updating customer");
}

delete删除数据的实现对比

// jdbcTemplate实现
public void delete(int id) {
  int deleted = jdbcTemplate.update("delete from customer where id = ?", id);
  Assert.state(deleted == 1 , "An exception error occurred while deleting customer");
}

// jdbcClient实现
public void delete(int id) {
  int deleted = jdbcClient.sql("delete from customer where id = :id").param("id",id).update();
  Assert.state(deleted == 1, "An exception error occurred while updating customer");
}

总结

上面我们分别演示了JdbcClient 和 JdbcTemplate从初始化到真正执行增删改查操作的代码样例。总体上来说，JdbcClient的实现更为简洁方便。如果不考虑其他ORM框架的情况下，在未来的Spring Boot版本中，我会更偏向于选择JdbcClient来操作数据库。那么您觉得怎么样呢？留言区一起聊聊～

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