关于spring:SpringJDBC

最近学了一下 Spring 的 JDBC 框架，写一篇文章总结一下，因为不太罕用，我就简略总结一下增删改查的用法，这里是基于 XML 配置进行的
留神：我这里应用的是本人的数据库，请将配置信息里的 datasource 数据源信息以及 sql 语句改成本人的电脑上的

• domain 实体类

public class User {
     private String account;
     private String password;
     private Float balance;
     public User(String account, String password, Float balance) {
     this.account = account;
     this.password = password;
     this.balance = balance;
     }
        public User(){}
        @Override
     public String toString() {
            return "User{" +
                    "account='" + account + '''+", password='"+ password +''' +
                    ", balance=" + balance +
                    '}';
     }
        public String getAccount() {return account;}
        public void setAccount(String account) {this.account = account;}
        public String getPassword() {return password;}
        public void setPassword(String password) {this.password = password;}
        public Float getBalance() {return balance;}
        public void setBalance(Float balance) {this.balance = balance;}
}

• dao 层的类

public class TestJDBC {
    // 数据源：在配置文件中配置，通过 Spring 主动注入
     private DataSource dataSource;
     // 调用增删改查的执行者
     private JdbcTemplate jdbcTemplate;
     public TestJDBC(){}
     
     // 初始化
     public TestJDBC(DataSource dataSource){
        this.dataSource = dataSource;
        jdbcTemplate = new JdbcTemplate(this.dataSource);
     }
     public void insert(User user){
        // 通过？代替传递进去的参数，必须和 update 办法传进去的参数程序统一
        String sql = "insert into atm values(?, ?, ?)";
        jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getBalance());
     }
     public void delete(String account){
        String sql = "delete from atm where account = ?";
        jdbcTemplate.update(sql, account);
     }
     public void update(User user){
        String sql = "update atm set account = ?, password = ?, balance = ? where account = ?";
        jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getBalance(), user.getAccount());
     }
        // 查问一条记录
     public User selectOne(String account){
        // 通过策略模式，将查问的后果包装成 User 对象
        String sql = "select * from atm where account = ?";
        return jdbcTemplate.queryForObject(sql, new RowMapper<User>(){
             @Override
             public User mapRow(ResultSet resultSet, int i) throws SQLException {String account = resultSet.getString("account");
                 String password = resultSet.getString("password");
                 Float balance = resultSet.getFloat("balance");
                 return new User(account, password, balance);
             }
            }, account);
     }
        // 查问多条记录
     public List<User> selectList(){
            String sql = "select *from atm";
            //query 办法依据该办法的返回值类型，将所有记录包装成 List 对象，而策略模式是将每一行记录包装成 User 对象
     return jdbcTemplate.query(sql, new RowMapper<User>() {
                @Override
     public User mapRow(ResultSet resultSet, int i) throws SQLException {String account = resultSet.getString("account");
     String password = resultSet.getString("password");
     Float balance = resultSet.getFloat("balance");
     return new User(account, password, balance);
     }
            });
     }
}

• 配置信息

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
 https://www.springframework.org/schema/beans/spring-beans.xsd">

<!--    JDBC-->
     <bean id="userJdbcTemplate" class="com.cjh.dao.TestJDBC" autowire="constructor"></bean>
     <bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
         <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
         <property name="url" value="jdbc:mysql://localhost:3306/bank?serverTimezone=CST"/>
         <property name="username" value="root"/>
         <property name="password" value="123456"/>
     </bean>
</beans>

• 主函数调用

public class TestMain {public static void main(String[] args) {System.out.println(userDao.selectUserByAccount("2018"));
        ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml");
        TestJDBC testJDBC = (TestJDBC) context.getBean("userJdbcTemplate");
        //testJDBC.insert(new User("0000", "0000", 999.0f));
        //testJDBC.insert(new User("0001", "0000", 999.0f));
        //testJDBC.delete("0000");
        //testJDBC.update(new User("0001", "1234", 999.0f));
        System.out.println(testJDBC.selectList());
    }
}