1、JdbcTemplate
spring对数据库的操作在jdbc上做了更深层次的封装JdbcTemplate
,处理了资源的建立和释放(不需要我们管理连接了),我们只需要提供SQL语句(不需要我们设置参数了)和提取结果(查询时候可以直接返回对应的实体类),使JDBC更加易于使用。它也可以使用spring的注入功能,将数据源注入JdbcTemplate
,来实现操作数据库。
2、JdbcTemplate常用方法
- update(更新数据)
- batchUpdate(批量更新数据)
- queryForObject(查询单行数据或者单值数据)
query(查询多行数据)
3、Spring中实现jdbcTemplate对数据库操作(采用c3p0连接池)
1、需要导入的jar包
- spring-jdbc-5.0.6.RELEASE.jar
- spring-tx-5.0.6.RELEASE.jar
- mysql-connector-java-5.0.7.jar
c3p0-0.9.5.2.jar
2、springxml配置
<context:property-placeholder location="classpath:jdbc.properties" /> <!-- 配置c3p0数据源 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="user" value="${jdbc.user}"></property> <property name="password" value="${jdbc.password}"></property> <property name="driverClass" value="${jdbc.driverClass}"></property> <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property> </bean> <!-- 将c3p0数据源注入jdbcTemplate --> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"></property> </bean>
3、User实体类
public class User { private int id; private String username; private String password; public User() { super(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Override public String toString() { return "User [id=" + id + ", username=" + username + ", password=" + password + "]"; } }
4、测试类
public void testUserServiceImpl() { //获取IOC容器 ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml"); //通过ApplicationContext对象的getBean方法来获取对象实例 //获取数据连接模板JdbcTemplate JdbcTemplate jdbcTemplate = (JdbcTemplate) context.getBean("jdbcTemplate"); //增加 String sql1 = "insert into user(username,password) values(?,?)"; System.out.println(jdbcTemplate.update(sql1, "user","user123")); //修改 String sql2 = "update user set username = ? where id = 10000"; System.out.println(jdbcTemplate.update(sql2, "adminadmin")); //查询基本数据 String sql3 = "select count(*) from user"; System.out.println(jdbcTemplate.queryForObject(sql3, Integer.class)); //查询单条记录 String sql4 = "select * from user where id = 10000"; RowMapper<User> rowMapper = new BeanPropertyRowMapper<>(User.class); User user = jdbcTemplate.queryForObject(sql4, rowMapper); System.out.println(user); //查询多条记录 String sql5 = "select * from user"; List<User> list = jdbcTemplate.query(sql5, rowMapper); for (User user2 : list) { System.out.println(user2); } //批量插入 String sql6 = "insert into user(username,password) values(?,?)"; List<Object[]> batchArgs=new ArrayList<Object[]>(); batchArgs.add(new Object[]{"aaaa","aaa123"}); batchArgs.add(new Object[]{"bbbb","bbb123"}); batchArgs.add(new Object[]{"cccc","ccc123"}); jdbcTemplate.batchUpdate(sql6, batchArgs); }