【Spring】Spring中的JdbcTemplate

JdbcTemplate

實體類：

public class Account implements Serializable {
    private Integer id;
    private String name;
    private Double money;
    //省略set方法
}

不使用ioc

public class JdbcTemplateDemo {
    public static void main(String[] args) {
        //準備數據源：Spring內置數據源
        DriverManagerDataSource ds = new DriverManagerDataSource();
        ds.setDriverClassName("com.mysql.jdbc.Driver");
        ds.setUrl("jdbc:mysql://localhost/test");
        ds.setUsername("root");
        ds.setPassword("1022");

        //創建JdbcTemplate對象
        JdbcTemplate jt = new JdbcTemplate();
        //給JdbcTemplate對象設置數據源
        jt.setDataSource(ds);
        //執行操作
        jt.execute("insert into account1(name,money)values('eee',998.0)");
    }
}

執行之後可以在數據庫中插入一條數據。

使用ioc實現增加一條內容

public class JdbcTemplateDemo {
    public static void main(String[] args) {
        //獲取容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        //獲取對象
        JdbcTemplate jt = ac.getBean("jdbcTemplate",JdbcTemplate.class);
        //執行操作
        jt.execute("insert into account1(name,money)values('fff',1200.0)");
    }
}

配置bean.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--配置JdbcTemplate-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!--配置數據源-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost/test"></property>
        <property name="username" value="root"></property>
        <property name="password" value="1022"></property>
    </bean>

</beans>

實現刪改查：

public class JdbcTemplateDemo2 {
    public static void main(String[] args) {
        //獲取容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        //獲取對象
        JdbcTemplate jt = ac.getBean("jdbcTemplate", JdbcTemplate.class);

        //執行操作
        // 保存
        jt.update("insert into account1(name,money)values(?,?)","ggg",1100.0);
        //執行保存
        jt.update("update account1 set name = ?,money=? where id=?","test",4567,4);
        //刪除
        jt.update("delete from account1 where id=?",7);

        //查詢所有金額大於1000的
        List<Account> accounts = jt.query("select * from account1 where money > ?", new BeanPropertyRowMapper<Account>(Account.class), 1000.0);
        for (Account account : accounts) {
            System.out.println(account);
        }

        //查詢一個
        List<Account> account = jt.query("select * from account1 where id = ?",new BeanPropertyRowMapper<Account>(Account.class), 2);
        System.out.println(account.isEmpty() ? "沒有結果" : account);
    }
}

增加Dao層對方法進行封裝：

public class AccountDaoImpl implements IAccountDao {

    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public Account findAccountById(int id) {
        List<Account> accounts = jdbcTemplate.query("select * from account1 where id = ?",new BeanPropertyRowMapper<Account>(Account.class),id);
        if(accounts.isEmpty()) return null;
        else return accounts.get(0);
    }

    public Account findAccountByName(String name) {
        List<Account> accounts = jdbcTemplate.query("select * from account1 where name = ?",new BeanPropertyRowMapper<Account>(Account.class),name);
        if(accounts.isEmpty()) return null;
        if(accounts.size()>1){
            throw new RuntimeException("查詢到的結果不止一個");
        }else return accounts.get(0);
    }

    public void updateAccount(Account account) {
        jdbcTemplate.update("insert into account1(name,money)values(?,?)","hhh",180.0);
    }
}

在bean.xml中注入參數：

    <!--配置賬戶的持久層-->
    <bean id="accountDao" class="com.lwl.dao.impl.AccountDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>

Dao層的第二種寫法：

public class AccountDaoImpl extends JdbcDaoSupport implements IAccountDao {

    private JdbcTemplate jdbcTemplate = super.getJdbcTemplate();
    //後面的不變
    public Account findAccountById(int id) {
        List<Account> accounts = jdbcTemplate.query("select * from account1 where id = ?",new BeanPropertyRowMapper<Account>(Account.class),id);
        if(accounts.isEmpty()) return null;
        else return accounts.get(0);
    }

    public Account findAccountByName(String name) {
        List<Account> accounts = jdbcTemplate.query("select * from account1 where name = ?",new BeanPropertyRowMapper<Account>(Account.class),name);
        if(accounts.isEmpty()) return null;
        if(accounts.size()>1){
            throw new RuntimeException("查詢到的結果不止一個");
        }else return accounts.get(0);
    }

    public void updateAccount(Account account) {
        jdbcTemplate.update("insert into account1(name,money)values(?,?)","hhh",180.0);
    }
}