Spring使用jdbcJdbcTemplate和三种方法配置数据源

三种方法配置数据源

1.需要引入jar包：spring-jdbc-4.3.2.RELEASE.jar

<!-- spring内置，springJdbc，配置数据源 -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
        <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"></property>
        <property name="username" value="123"></property>
        <property name="password" value="123"></property>
    </bean>

2.需要引入2个jar包：(1).spring-framework-3.0.2.RELEASE-dependencies\org.apache.commons\com.springsource.org.apache.commons.dbcp\1.2.2.osgi\com.springsource.org.apache.commons.dbcp-1.2.2.osgi.jar

(2).spring-framework-3.0.2.RELEASE-dependencies\org.apache.commons\com.springsource.org.apache.commons.pool\1.5.3\com.springsource.org.apache.commons.pool-1.5.3.jar

<!-- dbcp，配置数据源 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
        <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"></property>
        <property name="username" value="123"></property>
        <property name="password" value="123"></property>
    </bean>

3.c3p0配置数据源，并引用了一个在src目录下自定义创建的一个.properties文件，并使用${}设值

！需要引入jar包：spring-framework-3.0.2.RELEASE-dependencies\com.mchange.c3p0\com.springsource.com.mchange.v2.c3p0\0.9.1.2\com.springsource.com.mchange.v2.c3p0-0.9.1.2.jar

<!-- c3p0，配置数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.name}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

Spring连接数据库

1.创建dao

public interface SelectAllEmpDao {
    public void selectAll();
}

2.创建实现类

public class SelectAllEmpImpl extends JdbcDaoSupport implements SelectAllEmpDao {

    @Override
    public void selectAll() {
        String sql = "select * from emp";

        List<Map<String, Object>> list = this.getJdbcTemplate().queryForList(
                sql);

        List<Emp> empList = new ArrayList<Emp>();

        for (Map<String, Object> map : list) {
            Emp e = new Emp();
            e.setId(((BigDecimal) map.get("id")).intValueExact());
            e.setName(map.get("name").toString());
            e.setAge(((BigDecimal) map.get("age")).intValueExact());

            empList.add(e);
        }
    }
}

3.配置xml

(1)配置数据源

<!-- spring内置，springJdbc，配置数据源 -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
        <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"></property>
        <property name="username" value="bdqn"></property>
        <property name="password" value="bdqn"></property>
    </bean>

(2)配置jdbcTemplate，并引用dataSource

<!-- 配置template，并为其注入dataSource -->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

(3).注册业务bean,并引用jdbcTemplate

<!-- 查询emp所有记录数 -->
    <bean id="selectAllEmpDao" class="cn.cnsdhzzl.dao.impl.SelectAllEmpImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>

(4)测试

@Test
    // Spring使用jdbc查询表中所有记录
    public void selectAll() {
        ApplicationContext ac = new ClassPathXmlApplicationContext(
                "applicationContext.xml");

        SelectAllEmpDao selectAllEmpDao = (SelectAllEmpDao) ac
                .getBean("selectAllEmpDao");

        selectAllEmpDao.selectAll();
    }

注：由于底层进行了判断所以可以省略引用jdbcTemplate，直接引用dateSource。