1.概念
Spring JDBC 是 Spring 所提供的持久层技术，以更直接、更简洁的方式使用 JDBC API。
不同形式的数据源配置：
（1）Spring 自带的数据源
依赖包：import org.springframework.jdbc.datasource.DriverManagerDataSource;
@Bean
public DriverManagerDataSource dataSource() {
DriverManagerDataSource ds = new DriverManagerDataSource()
ds
.setDriverClassName(env
.getProperty(
"spring.datasource.driver-class-name"))
ds
.setUrl(env
.getProperty(
"spring.datasource.url"))
ds
.setUsername(env
.getProperty(
"spring.datasource.username"))
ds
.setPassword(env
.getProperty(
"spring.datasource.password"))
return ds
}
（2）数据源连接池
依赖包：import org.apache.tomcat.jdbc.pool.DataSource;
@Bean(destroyMethod =
"close")
public DataSource dataSource() {
DataSource ds = new DataSource()
ds
.setDriverClassName(env
.getProperty(
"spring.datasource.driver-class-name"))
ds
.setUrl(env
.getProperty(
"spring.datasource.url"))
ds
.setUsername(env
.getProperty(
"spring.datasource.username"))
ds
.setPassword(env
.getProperty(
"spring.datasource.password"))
return ds
}
说明： 设定 destroyMethod = “close” 属性，以使 Spring 容器关闭时，数据源能够正常关闭。
2.使用 JDBC 连接数据库
2.1 Java 配置
@Configuration
public class JdbcConfig {
@Autowired
public Environment env;
@Bean(destroyMethod =
"close")
public DataSource
dataSource() {
DataSource ds =
new DataSource();
ds.setDriverClassName(env.getProperty(
"spring.datasource.driver-class-name"));
ds.setUrl(env.getProperty(
"spring.datasource.url"));
ds.setUsername(env.getProperty(
"spring.datasource.username"));
ds.setPassword(env.getProperty(
"spring.datasource.password"));
return ds;
}
@Bean
public JdbcTemplate
jdbcTemplate() {
JdbcTemplate jt =
new JdbcTemplate();
jt.setDataSource(dataSource());
return jt;
}
@Bean
public ForumDao
forumDao() {
return new ForumDao();
}
}
2.2 XML 配置
在 Spring 配置文件中配置 DAO 的 4 个步骤： （1）定义 DataSource （2）定义 JdbcTemplate （3）声明一个抽象的 ，以便所有 DAO 复用配置 JdbcTemplate 属性的配置。 （4）配置具体的 DAO。
<context:component-scan base-package="com.chen.jdbc"/>
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close"
p:defaultAutoCommit="false"
p:driverClassName="${jdbc.driverClassName}"
p:url="${jdbc.url}"
p:username="${jdbc.username}"
p:password="${jdbc.password}"/>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource"/>
<bean id="forumDao" class="com.chen.jdbc.dao.ForumDao"/>
使用 JdbcTemplate 对数据进行 CURD 操作。
2.3 更改数据代码
@Repository
public class ForumDao {
private JdbcTemplate jdbcTemplate;
@Autowired
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
public void addForum(Forum forum) {
String sql =
" INSERT INTO t_forum(forum_name, forum_desc) VALUES (?,?) ";
Object[]
params =
new Object[]{forum.getForumName(), forum.getForumDesc()};
jdbcTemplate.update(sql,
params);
}
}
2.4 查询数据代码
public Forum
findByForumName(
final String forumName) {
String sql =
" SELECT * FROM t_forum WHERE forum_name = ? ";
final Forum forum =
new Forum();
jdbcTemplate.query(sql,
new Object[]{forumName},
new RowCallbackHandler() {
@Override
public void processRow(ResultSet rs)
throws SQLException {
forum.setForumId(rs.getInt(
"forum_id"));
forum.setForumName(forumName);
forum.setForumDesc(rs.getString(
"forum_desc"));
}
});
return forum;
}
2.5 查询单值数据代码
public int getForumNum() {
String sql =
" SELECT count(*) FROM t_forum ";
return jdbcTemplate.queryForObject(sql, Integer.class);
}
3.使用 JPA 连接数据库
3.1 Domain实体类
@Entity
@Table(name =
"t_customer")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String firstName;
private String lastName;
protected Customer() {
}
public Customer(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
@Override
public String
toString() {
return String.format(
"Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
}
}
3.2 Dao接口（继承JpaRepository）
public interface CustomerRepository extends CrudRepository<Customer, Long> {
List<Customer> findByLastName(String lastName);
}
3.3 Application应用
@SpringBootApplication
public class CustomerApp {
private static final Logger
log = LoggerFactory.getLogger(CustomerApp.
class);
public static void main(String[] args) {
SpringApplication.run(CustomerApp.
class);
}
@Bean
public CommandLineRunner demo(CustomerRepository repository) {
return (args) -> {
repository.save(
new Customer(
"Jack",
"Bauer"));
repository.save(
new Customer(
"Kim",
"Bauer"));
repository.save(
new Customer(
"David",
"Palmer"));
log.info(
"Customers found with findAll():");
log.info(
"-------------------------------");
for (Customer customer : repository.findAll()) {
log.info(customer.toString());
}
log.info(
"");
Customer customer = repository.findOne(
1L);
log.info(
"Customer found with findOne(1L):");
log.info(
"--------------------------------");
log.info(customer.toString());
log.info(
"");
log.info(
"Customer found with findByLastName('Bauer'):");
log.info(
"--------------------------------------------");
for (Customer bauer : repository.findByLastName(
"Bauer")) {
log.info(bauer.toString());
}
log.info(
"");
};
}
}
源代码： https://github.com/leifchen/hello-spring 代码包：com.chen.jdbc
