所需maven配置
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.6</version>
</dependency>
// JDBC模板依赖于连接池来获得数据的连接,所以必须先要构造连接池
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/spring");
dataSource.setUsername("root");
dataSource.setPassword("123456");
// 创建JDBC模板
JdbcTemplate jdbcTemplate = new JdbcTemplate();
// 这里也可以使用构造方法
jdbcTemplate.setDataSource(dataSource);
// sql语句
String sql = "select count(*) from user";
Long num = (long) jdbcTemplate.queryForObject(sql, Long.class);
System.out.println(num);