tomcat的连接池配置问题

1.tomcat的连接池配置

tomcat安装目录下->conf文件夹下->context.xml

添加以下配置代码

<Resource name="ds_mysql"
type="javax.sql.DataSource"
maxActive="100" maxIdle="50" maxWait="5000"
username="root" password="123"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://127.0.0.1:3306/testjdbc" />

tomcat一启动就会去加载DataSource这个类，去初始化datasource 获得这个连接

在tomcat的lib目录下放入connection-pool.jar和connection-dbcp.jar 和mysql驱动的jar包就可以在项目中使用

2.DataSource数据源的使用

public class DataSourceContextListener implements ServletContextListener{

@Override
public void contextDestroyed(ServletContextEvent arg0) {
// TODO Auto-generated method stub

}

@Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("--------------Initial-----------------");
try {
Context context = new InitialContext();
Object obj = context.lookup("java:comp/env/ds_mysql");
DataSource ds = (DataSource) obj;
arg0.getServletContext().setAttribute("dataSource", ds);
} catch (NamingException e) {

e.printStackTrace();
}
}
}

public void init() throws ServletException {
try {
DataSource ds = (DataSource) getServletContext().getAttribute("dataSource");
System.out.println("ds --> " + ds);
Connection con = ds.getConnection();
System.out.println("con --> " + con);
} catch (SQLException e) {

e.printStackTrace();
}
}

<listener>
<listener-class>org.crazyit.servlet.DataSourceContextListener</listener-class>
</listener>