Spring4学习笔记（九）：JDBCTemplate

1、c3p0.jar和对应的mchange-common.jar包导入正确 导入11个spring的必要包 2、编写db.properties属性文件

jdbc.user=root jdbc.password=123456 jdbc.driverClass=com.mysql.jdbc.Driver jdbc.jdbcUrl=jdbc:mysql://localhost:3306/spring jdbc.initPoolsize=5 jdbc.maxPoolsize=10

3、编写applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd"> <!-- 扫描包 --> <context:component-scan base-package="com.whiteblack"></context:component-scan> <!-- 导入资源文件 --> <context:property-placeholder location="classpath:db.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> <property name="initialPoolSize" value="${jdbc.initPoolsize}"></property> <property name="maxPoolSize" value="${jdbc.maxPoolsize}"></property> </bean> <!-- 配置Spring 的JdbcTemplate --> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"></property> </bean> </beans>

4、编写测试

public class JDBCTest { private ApplicationContext ctx = null; private JdbcTemplate jdbcTemplate; private NamedParameterJdbcTemplate namedPJT; { ctx = new ClassPathXmlApplicationContext("applicationContext.xml"); jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate"); namedPJT = ctx.getBean(NamedParameterJdbcTemplate.class); } /** *1.Sql语句中的参数名和类的属性一致 *2.使用SqlParameterSource 的BeanPropertySqlParameterSource 实现类作为参数 */ @Test public void testNamedParameterJdbcTemplate2(){ String sql = "INSERT INTO employee(last_name,email,dept_id)" + "VALUES(:lastName,:email,:deptId)"; Employee employee = new Employee(); employee.setLastName("XT"); employee.setEmail("xy@qq.com"); employee.setDeptId(2); SqlParameterSource paramSource = new BeanPropertySqlParameterSource(employee); namedPJT.update(sql, paramSource); } /** * 使用具名参数时可以使用update(String sql,SqlParameterSource paramSource)方法进行更新操作 * * 可以给参数起名字，多个参数时维护性更高，但是麻烦 */ @Test public void testNamedParameterJdbcTemplate(){ String sql = "INSERT INTO employee(last_name, email, dept_id) VALUES(:ln,:email,:deptid)"; Map<String, Object> paramMap = new HashMap<>(); paramMap.put("ln", "FF"); paramMap.put("email", "ff@qq.com"); paramMap.put("deptid", 1); namedPJT.update(sql,paramMap); } // @Test // public void testDelete(){ // // String sql = "DELETE FROM employee where id > ?"; // jdbcTemplate.update(sql, 6); // } /** * 获取单个列的值便于统计 * 使用.queryForObject(String sql, Class<Long> requiredType) throws DataAccessException */ @Test public void testQueryForCount(){ String sql = "SELECT count(id) FROM employee"; long count = jdbcTemplate.queryForObject(sql, Long.class); System.out.println(count); } /** * 查到实体类对象的集合 */ @Test public void testQueryForList(){ String sql = "SELECT id,last_name lastName,email from employee where id > ?"; RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class); List<Employee> employees = jdbcTemplate.query(sql, rowMapper , 6); System.out.println(employees); } /** * 从数据库获取一条记录，实际得到一个对象 * 注意是调用queryForObject(String sql, RowMapper<Employee> rowMapper, Object... args)方法 * 1.其中RowMapper 指定如何去映射结果集的行，常用的实现类BeanPropertyRowMapper<> * 2.使用SQL列名的别名实现类属性的映射 * 3.不支持级联属性，不是ORM框架 */ @Test public void testQueryForObject() { String sql = "SELECT id,last_name lastName,email from employee where id = ?"; RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class); Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 1); System.out.println(employee); } /** * 执行批量的更新 * 最后一个参数是Object[] 的List 类型：因为修改一条记录需要一个Object[] ,那么多条不就是使用数组的集合 */ @Test public void testBatchUpdate(){ String sql = "INSERT INTO employee(last_name,email,dept_id) VALUES(?,?,?)"; List<Object[]> batchArgs = new ArrayList<>(); batchArgs.add(new Object[]{"AA","aa@mail",1}); batchArgs.add(new Object[]{"BB","bb@mail",2}); batchArgs.add(new Object[]{"CC","cc@mail",3}); batchArgs.add(new Object[]{"DD","dd@mail",4}); jdbcTemplate.batchUpdate(sql, batchArgs); } /** * 执行INSERT,UPDATE,DELETE语句 * */ @Test public void testUpdate(){ String sql = "UPDATE t_book SET b_stock = ? WHERE b_number = ?"; jdbcTemplate.update(sql, 5, 1002); } //测试是否数据源是否配置成功 @Test public void testDataSource() throws SQLException { DataSource dataSource = (DataSource) ctx.getBean("dataSource"); System.out.println(dataSource.getConnection()); } }