<来源网址:http://dev.21tx.com/2004/10/10/12348.html>
DAO应该是现在比较流行的一种开发模式.不管是用什么更新的技术,Hibernate或者其它的.DAO模式是应该遵循的.
我写DAO大概是这样的:一个DAO接口,定义好要实现的方法名称;一个Impl实现类,主要控制连接及关闭数据库;
接下来会有一个写具体方法的数据库实现类;还有一个工厂类,可以更灵活的取得不同的DAO.
上面的写法感觉上不错,但是写起来比较麻烦,而且如果使用数据库连接池的活,利用JUnit做测试的时候会比较麻烦.
下面我们利用Spring的JDBC模板写一个DAO测试实例,你会发现它是如此的简单且实用.
使用的了DBCP的连接池.
下面是要引入的JAR包
<classpathentry kind="lib" path="D:/classes/spring.jar"/>
<classpathentry kind="lib" path="D:/classes/junit-3.8.1.jar"/>
<classpathentry kind="lib" path="D:/classes/spring-dao.jar"/>
<classpathentry kind="lib" path="D:/classes/MySQL-connector-Java-3.0.9-stable-bin.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-dbcp-1.1.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-pool-1.1.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-collections.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-beanutils.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-lang-2.0.jar"/>
<classpathentry kind="lib" path="D:/classes/commons-logging-1.0.3.jar"/>
SpringDao.java文件
package com.bcxy.spring.dao; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import javax.sql.DataSource; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springFramework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.PreparedStatementSetter; import org.springframework.jdbc.core.RowCallbackHandler; import com.bcxy.spring.dao.model.TestModel; public class SpringDao { DataSource ds = null; JdbcTemplate jt = null; Log log = LogFactory.getLog(SpringDao.class); public List springQuery(){ final List tests = new ArrayList(); String sql = " select * from test "; jt = new JdbcTemplate(ds); jt.query(sql, new RowCallbackHandler(){ public void processRow(ResultSet rs) throws SQLException { // TestModel tm = new TestModel(); tm.setId(rs.getInt("id")); tm.setPw(rs.getString("pw")); tm.setUn(rs.getString("un")); // tests.add(tm); } }); return tests; } public void springUpdate() { String sql = "update test set pw=? where id=?"; jt = new JdbcTemplate(ds); jt.update(sql, new PreparedStatementSetter() { public void setValues(PreparedStatement ps) throws SQLException { // ps.setString(1, "maxcard"); ps.setInt(2, 1); } }); log.info("update test a record."); } /** * @return */ public DataSource getDs() { return ds; } /** * @param source */ public void setDs(DataSource source) { ds = source; } }
Spring配置文件
<?XML version="1.0" encoding="UTF-8" ?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <description>Spring Quick Start</description> <!-- datasource --> <bean id="datasource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName"> <value>com.mysql.jdbc.Driver</value> </property> <property name="url"> <value>jdbc:mysql://localhost/test</value> </property> <property name="username"> <value>root</value> </property> <property name="password"> <value></value> </property> </bean> <!-- test dao --> <bean id="testdao" class="com.bcxy.spring.dao.SpringDao" > <property name="ds"> <ref local="datasource"/> </property> </bean> </beans>
下面我们用JUnit测试一下:
......
public void testSpringUpdate() throws FileNotFoundException { // InputStream is = new FileInputStream("bean.xml"); XmlBeanFactory bean = new XmlBeanFactory(is); SpringDao sd = (SpringDao)bean.getBean("testdao"); sd.springUpdate(); }
......
执行成功后检查一下数据库吧....