配置数据源
(1)导入相关依赖
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.25</version>
</dependency>
<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.5</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.6</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
(2)创建数据源连接测试类 DataSourceTest
对于数据库连接池 c3p0 和 druid 的创建,首先需要创建数据源对象,然后设置连接信息,最后获取连接资源即可,使用结束后需归还资源,这两种连接池的创建步骤一致,相关方法名有些许不同
import com.alibaba.druid.pool.DruidDataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
public class DataSourceTest {
@Test
public void createC3p0() throws PropertyVetoException, SQLException {
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/xyz");
dataSource.setUser("root");
dataSource.setPassword("admin");
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
@Test
public void createDruid() throws SQLException {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/xyz");
dataSource.setUsername("root");
dataSource.setPassword("admin");
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
}
连接信息解耦
(1)将连接信息保存在 resources 下的 jdbc.properties 中
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/xyz
jdbc.username=root
jdbc.password=admin
(2)使用 ResourceBundle 读取 properties 配置文件,创建数据源连接
import com.alibaba.druid.pool.DruidDataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ResourceBundle;
public class DataSourceTest {
@Test
public void createC3p0() throws PropertyVetoException, SQLException {
ResourceBundle rb = ResourceBundle.getBundle("jdbc");
String driver = rb.getString("jdbc.driver");
String url = rb.getString("jdbc.url");
String username = rb.getString("jdbc.username");
String password = rb.getString("jdbc.password");
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass(driver);
dataSource.setJdbcUrl(url);
dataSource.setUser(username);
dataSource.setPassword(password);
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
@Test
public void createDruid() throws SQLException {
ResourceBundle rb = ResourceBundle.getBundle("jdbc");
String driver = rb.getString("jdbc.driver");
String url = rb.getString("jdbc.url");
String username = rb.getString("jdbc.username");
String password = rb.getString("jdbc.password");
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(driver);
dataSource.setUrl(url);
dataSource.setUsername(username);
dataSource.setPassword(password);
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
}
getBundle() 方法需要传入待加载的 properties 文件名(不需要扩展名),这里的路径是相对于类的根路径而言的
Spring 配置数据源
(1)加载 properties 文件,读取连接信息
对于 properties 文件的读取,首先声明 context 命名空间,在 xml 配置文件的 <beans> 标签上增加如下代码
xmlns:context="http://www.springframework.org/schema/context"
以及在 xsi:schemaLocation 后面增加
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
使用 <context:property-placeholder> 标签加载 properties 文件,用 location 指定文件路径,这里的路径是相对于类的根路径而言的
<context:property-placeholder location="jdbc.properties"/>
(2)在 xml 配置文件中配置数据源对象的 bean ,并设置连接信息
使用 EL 表达式将 properties 文件中的连接信息传给对应的 bean 的属性
<bean id="dataSource_c3p0" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<bean id="dataSource_druid" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
完整 xml 配置文件如下:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:property-placeholder location="jdbc.properties"/>
<bean id="dataSource_c3p0" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<bean id="dataSource_druid" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
</beans>