手写 Hibernate ORM 框架-03-Hibernate 配置文件读取, 数据库连接构建

目录

• 目录
• 本节内容
• 读取
  • 文件内容
  • 读取测试
• 构建 Connetion
• 目录导航

本节内容

配置文件的读取

数据库访问 Connection 的构建

读取

当然，代码中为了快速模拟，我们也可以将属性 hard code。

但此处为了模拟，就进行简单的实现

文件内容

<?xml version='1.0' encoding='utf-8'?>
<hibernate-configuration>
        <!-- Database connection settings -->
        <property name="connection.driver_class"></property>
        <property name="">jdbc:mysql://localhost:3306/hibernate</property>
        <property name="">root</property>
        <property name="">123456</property>
</hibernate-configuration>

读取测试

• 测试

package .dom4j;

import org.;
import org.;
import org.;
import ;

import ;

/**
 * Created by houbinbin on 16/6/5.
 */
public class HibernateConfigRead {
    @Test
    public void testRead() throws Exception {
        (getClass().getClassLoader().getResource(""));
        SAXReader reader = new SAXReader();
        Document document = (getClass().getClassLoader().getResource(""));
        Element root = ();

        // iterate through child elements of root
        for (Iterator i = (); (); ) {
            Element element = (Element) ();
            (("name"));
            (()+" == "+());  //获取值
        }
    }
}

• 结果

file:/Users/houbinbin/code/_orm/hibernate-simulator/target/classes/hibernate.cfg.xml
connection.driver_class
com.mysql.jdbc.Driver == com.mysql.jdbc.Driver
connection.url
jdbc:mysql://localhost:3306/hibernate == jdbc:mysql://localhost:3306/hibernate
connection.username
root == root
connection.password
123456 == 123456

构建 Connetion

数据库链接构建

package ;

import ;

import org.;
import org.;
import org.;
import org.;

import ;
import ;
import ;
import ;
import ;

/**
 * 数据库链接信息
 *
 * @author houbinbin
 * @date 16/6/5
 */
public class ConnectionUtil {

    private ConnectionUtil() {
    }

    /**
     * 根据配置信息 获取数据库链接
     *
     * @return Connection
     */
    public static Connection getConnection() {
        Connection connection = null;

        Map<String, String> config = getJDBCConfig();
        try {
            (("connection.driver_class"));
            connection = (Connection) ((""), (""),
                    (""));
        } catch (ClassNotFoundException | SQLException e) {
            ();
        }

        return connection;
    }


    /**
     * 获取 JDBC 配置信息
     *
     * @return map
     */
    private static Map<String, String> getJDBCConfig() {
        Map<String, String> config = new HashMap<>();

        SAXReader reader = new SAXReader();
        Document document = null;
        try {
            document = (().getResource(""));
        } catch (DocumentException e) {
            ();
        }
        assert document != null;
        Element root = ();
        for (Iterator i = (); (); ) {
            Element element = (Element) ();
            (("name"), ());
        }

        return config;
    }
}

目录导航

目录导航