Spring JDBC
Spirng JDBC
一：采用Maven 引入 jar:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- MySQL database driver -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.15</version>
</dependency>
引入 spring jdbc 和 mysql 驱动；
二：数据库中建表；采用 mysql数据库；
DROP TABLE IF EXISTS `stock`; CREATE TABLE `stock` ( `STOCK_ID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT, `STOCK_CODE` VARCHAR(10) NOT NULL, `STOCK_NAME` VARCHAR(20) NOT NULL, PRIMARY KEY (`STOCK_ID`) USING BTREE, UNIQUE KEY `UNI_STOCK_NAME` (`STOCK_NAME`), UNIQUE KEY `UNI_STOCK_ID` (`STOCK_CODE`) USING BTREE ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
三：构建对应的类：
package com.myapp.core.jdbc;
public class Stock {
private int stock_id;
private String stock_name;
private String stock_code;
public int getStock_id() {
return stock_id;
}
public void setStock_id(int stock_id) {
this.stock_id = stock_id;
}
public String getStock_name() {
return stock_name;
}
public void setStock_name(String stock_name) {
this.stock_name = stock_name;
}
public String getStock_code() {
return stock_code;
}
public void setStock_code(String stock_code) {
this.stock_code = stock_code;
}
}
四：构建对应的 dao
package com.myapp.core.jdbc;
public interface StockDao {
public void insert(Stock stock);
public Stock findStockById(int id);
}
package com.myapp.core.jdbc;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.sql.DataSource;
public class StockDaoImpl implements StockDao{
private DataSource dataSource;
public DataSource getDataSource() {
return dataSource;
}
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}
Connection conn = null;
PreparedStatement prep = null;
@Override
public void insert(Stock stock) {
// TODO Auto-generated method stub
String sql ="insert into stock values(?,?,?)";
try{
conn = dataSource.getConnection();
prep = conn.prepareStatement(sql);
prep.setInt(1, stock.getStock_id());
prep.setString(2, stock.getStock_code());
prep.setString(3, stock.getStock_name());
boolean flag = prep.execute();
System.out.println(flag);
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if(prep != null){
prep.close();
}
if(conn != null){
conn.close();
}
}catch(Exception ex){
ex.printStackTrace();
}
}
}
@Override
public Stock findStockById(int id) {
// TODO Auto-generated method stub
String sql = "select * from stock where stock_id = ?";
ResultSet rs = null;
Stock stock = null;
try{
conn = dataSource.getConnection();
prep = conn.prepareStatement(sql);
prep.setInt(1, id);
rs = prep.executeQuery();
stock = new Stock();
while(rs.next()){
stock.setStock_id(id);
stock.setStock_code(rs.getString(2));
stock.setStock_name(rs.getString("stock_name"));
}
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if(prep != null){
prep.close();
}
if(conn != null){
conn.close();
}
}catch(Exception ex){
ex.printStackTrace();
}
}
return stock;
}
}
五：对应的spring xml 配置注入
<!-- setting the datasource -->
<bean id="stockDao" class="com.myapp.core.jdbc.StockDaoImpl">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mybase" />
<property name="username" value="root" />
<property name="password" value="root" />
</bean>
六：构建测试类：
package com.myapp.core.jdbc;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("resource/datasources.xml");
StockDao stockDao = (StockDao)context.getBean("stockDao");
/* Stock stock = new Stock();
stock.setStock_id(61);
stock.setStock_code("code1");
stock.setStock_name("name1");*/
// stockDao.insert(stock);
Stock stock =stockDao.findStockById(51);
System.out.println("id:"+stock.getStock_id()+","+stock.getStock_code()+","+stock.getStock_name());
}
}
七：maven 编译 引入jar：
E:\workspace\Spring3Example>mvn compile
E:\workspace\Spring3Example>mvn eclipse:eclipse
以上是通过mvn编译，再转换为eclipse项目。
八：运行结果
id:51,code,name
从数据库中取出了相应的数据。
九：扩展：使用 PropertyPlaceholderConfigurer 通过占位符(placeholder)进行配置 jdbc连接
1：定义database.properties文件
jdbc.driverClassName=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/mybase jdbc.username=root jdbc.password=root
2：通过配置文件定位database.properties文件的位置：
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>resource/database.properties</value>
</property>
</bean>
3：通过占位符配置数据源bean
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean>
4：测试结果：
id:51,code,name
一样可以查询出结果，测试成功，over
解决疑问：
为什么用
PropertyPlaceholderConfigurer类可以加载定位文件
PropertyPlaceholderConfigurer实现了接口BeanFactoryPostProcessor所有实现了 BeanFactoryPostProcessor接口的实现类会在其他bean是创建之前完成加载和创建，如果一个对象实现了BeanFactoryPostProcessor接口，会在优先进行加载处理。Application contexts can auto-detect BeanFactoryPostProcessor beans in their bean definitions and apply them before any other beans get created.当spring 容器启动是时候，会自动检测那些bean实现了BeanFactoryPostProcessor接口，进行优先处理。关于 BeanFactoryPostProcessor的详细讲解 here