JdbcTemplate介绍
为了使 JDBC 更加易于使用,Spring 在 JDBCAPI 上定义了一个抽象层, 以此建立一个JDBC存取框架,Spring Boot Spring Data-JPA。
作为 SpringJDBC 框架的核心, JDBC 模板的设计目的是为不同类型的JDBC操作提供模板方法. 每个模板方法都能控制整个过程,并允许覆盖过程中的特定任务。
通过这种方式,可以在尽可能保留灵活性的情况下,将数据库存取的工作量降到最低。
JdbcTemplate方法介绍
JdbcTemplate主要提供以下五类方法:
1、execute方法:可以用于执行任何SQL语句,一般用于执行DDL语句;
Execute、executeQuery、executeUpdate
2、update方法及batchUpdate方法:update方法用于执行新增、修改、删除等语句;batchUpdate方法用于执行批处理相关语句 SQL SERVCER(GO SQL语句 GO) ;
3、query方法及queryForXXX方法:用于执行查询相关语句;
4、call方法:用于执行存储过程、函数相关语句。
JdbcTemplate实现增删改查
JdbcTemplate添加数据
1. 使用配置实现
1.1 创建实体类
public class Account { private Integer accountid; private String accountname; private Double balance; public Integer getAccountid() { return accountid; } public void setAccountid(Integer accountid) { this.accountid = accountid; } public String getAccountname() { return accountname; } public void setAccountname(String accountname) { this.accountname = accountname; } public Double getBalance() { return balance; } public void setBalance(Double balance) { this.balance = balance; } }
1.2 创建Dao层
//查询所有所有账户 public ListgetAllAccounts();
.3 创建Dao层实现类并继承JdbcDaoSupport接口
public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao { @Override public ListgetAllAccounts() { JdbcTemplate jdbcTemplate = getJdbcTemplate(); String sql = "select * from accounts"; //RowMapper:接口 封装了记录的行映射关系 List lists = jdbcTemplate.query(sql, new RowMapper () { @Override public Account mapRow(ResultSet resultSet, int i) throws SQLException { //创建Account对象 Account account = new Account(); //从ResultSet中解数据保到Accounts对象中 account.setAccountid(resultSet.getInt("accountid")); account.setAccountname(resultSet.getString("accountname")); account.setBalance(resultSet.getDouble("balance")); return account; } }); return account; }
1.4创建Service层
//查询所有所有账户 public ListgetAllAccounts();
1.5创建Service层实现类
AccountDao accountDao; @Override public ListgetAllAccounts() { List allAccounts = accountDao.getAllAccounts(); return allAccounts; }
1.6 编写applicationContext.xml文件
<context:property-placeholder location="classpath:jdbc.properties"/> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${jdbc.driver}">property> <property name="url" value="${jdbc.url}">property> <property name="username" value="${jdbc.username}">property> <property name="password" value="${jdbc.password}">property> bean> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource">property> bean> <bean id="accountDao" class="cn.spring.accounttest.dao.impl.AccountDaoImpl"> <property name="jdbcTemplate" ref="jdbcTemplate">property> bean> <bean id="accountService" class="cn.spring.accounttest.service.impl.AccountServiceImpl"> <property name="accountDao" ref="accountDao">property> bean>
1.7编写测试类
@Test public void getAllAccount(){ ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml"); //从spring容器中获取Service对象 AccountService accountService = (AccountService)context.getBean("accountService"); ListallAccounts = accountService.getAllAccounts(); for (Account account:allAccounts) { System.out.println("账户名:"+account.getAccountname()+",余额为:"+account.getBalance()); } }
2. 使用注解方式实现
2.1 创建实体类
实体类
2.2 创建Dao层
查询方法
2.3 创建Dao层实现类
@Repository public class AccountDaoImpl implements AccountDao { @Autowired private JdbcTemplate jdbcTemplate; Account account = new Account(); @Override public ListgetAllAccounts() { String sql = "select * from accounts"; //自动映射 RowMapper rowMapper = new BeanPropertyRowMapper<>(Account.class); List query = jdbcTemplate.query(sql, rowMapper); for (Account account : query) { System.out.println(account); } return query; } }
2.4创建Service层
查询方法
2.5创建Service层实现类
实现查询方法
2.6编写applicationContext.xml文件
<context:component-scan base-package="cn.spring"/> <context:property-placeholder location="classpath:jdbc.properties"/> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${jdbc.driver}">property> <property name="url" value="${jdbc.url}">property> <property name="username" value="${jdbc.username}">property> <property name="password" value="${jdbc.password}">property> bean> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource">property> bean>
2.7编写测试类
查询测试类
JdbcTemplate实现增删改操作
使用注解方式实现,配置式同添加操作
1.创建Dao层
//删除账户 public int delAccount(int id); //添加用户 public int addAccount(Account account); //修改账户 public int updaAccount(Account account);
2.创建Dao曾实现类
@Override public int delAccount(int id) { String sql="delete from accounts where accountid=2"; int count = jdbcTemplate.update(sql); return count; } @Override public int addAccount(Account account) { String sql="insert into Accounts(accountname,balance) values(?,?)"; int count = jdbcTemplate.update(sql,account.getAccountname(),account.getBalance()); return count; } @Override public int updaAccount(Account account) { String sql="update accounts set accountname=?,balance=? where accountid=?"; int count = jdbcTemplate.update(sql, account.getAccountname(),account.getBalance(),account.getAccountid() ); return count; }
3. 创建Service层
增删改方法
4. 创建Service层实现类
增删改方法实现类
5. 编写applicationContext.xml文件
applicationContext.xml
6. 编写测试类
@Test public void delAccount(){ ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml"); AccountService accountService =(AccountService) context.getBean("accountServiceImpl"); int i = accountService.delAccount(2); if (i>0){ System.out.println("删除成功"); } } @Test public void addAccount(){ ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml"); AccountService accountServiceImpl = (AccountService) context.getBean("accountServiceImpl"); Account account=new Account(); account.setAccountname("刘磊"); account.setBalance(Double.valueOf(784)); int count = accountServiceImpl.addAccount(account); if (count>0){ System.out.println("添加成功"); } } @Test public void updaAcccount(){ ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml"); AccountService accountServiceImpl = (AccountService) context.getBean("accountServiceImpl"); Account account=new Account(); account.setAccountid(10); account.setAccountname("刘磊"); account.setBalance(Double.valueOf(784)); int count = accountServiceImpl.updaAccount(account); if (count>0){ System.out.println("修改成功"); } }