<?xml version="1.0" encoding="GBK" ?>

<sxtConfig>

<!-- 本次 连接  mysql 数据库-->

    <database-type>mysql</database-type>

    <database type="oracle">

        <className>oracle.jdbc.driver.OracleDriver</className>

        <url>jdbc:oracle:thin:@localhost:1521:orcl</url>

        <user>scott</user>

        <pwd>tiger</pwd>

    </database>

    <database type="mysql">

        <className>com.mysql.jdbc.Driver</className>

        <url>jdbc:mysql://localhost:3306/test</url>

        <user>root</user>

        <pwd>clc</pwd>

    </database>

</sxtConfig>

package dbutil;

import java.io.InputStream;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.List;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Element;

import org.dom4j.io.SAXReader;

public class JDBCUtil {

    public static String className;

    public static String url ;

    public static String user;

    public static String pwd ;

    /**

     * DOM4j解析xml

     */

    static {

        try {

            // 开始解析配置文件

            SAXReader saxReader = new SAXReader();

            // 以流的方式读取配置文件

            InputStream inputStream = JDBUtil.class.getClassLoader().getResourceAsStream("DBUtil.xml");

            // 开始配置文件

            Document document = saxReader.read(inputStream);

            // 获取根节点

            Element rootElement = document.getRootElement();

            // 获取要选择的数据库类型

            String databaseType = rootElement.elementText("database-type");

            // 判断数据库类型是否为空

            if (databaseType != null) {

                // 遍历出数据库的配置信息

                List<Element> elements = rootElement.elements("database");

                for (Element element : elements) {

                    // 判断数据库是否一致

                    if (databaseType.equals(element.attributeValue("type"))) {

                        // 获取当前元素的所有子元素

                        className = element.elementText("className");

                        url = element.elementText("url");

                        user = element.elementText("user");

                        pwd = element.elementText("pwd");

                    }

                }

                // 使用静态代码块加载驱动

                Class.forName(className);

            } else {

                System.out.println("您的配置文件数据库类型【database-type】有误，请重新配置");

            }

        } catch (DocumentException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    /**

     * 创建JDBC连接 connection的连接和事务的提交方式

     */

    public static Connection createConnection() {

        return createConnection(true);

    }

    // 事务的提交

    private static Connection createConnection(boolean autoCommit) {

        // 声明连接

        Connection connection = null;

        try {

            // 获取连接

            connection = DriverManager.getConnection(url, user, pwd);

            // 事务的提交方式

            connection.setAutoCommit(autoCommit);

            System.out.println("数据库连接成功");

        } catch (SQLException e) {

            System.out.println("您的数据库详细配置有误url【" + url + "】user【" + user + "】pwd【" + pwd + "】");

            e.printStackTrace();

        }

        return connection;

    }

    /**

     * 获取发送器 statement

     */

    public static Statement createStatemen(Connection connection) {

        Statement statement = null;

        try {

            statement = connection.createStatement();

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return statement;

    }

    /**

     * 获取预处理发送器

     */

    public static PreparedStatement createPreparedStatement(Connection connection, CharSequence sql) {

        PreparedStatement preparedStatement = null;

        try {

            preparedStatement = connection.prepareStatement(sql.toString());

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return preparedStatement;

    }

    /**

     * 关闭连接connection

     */

    private static void closeConnection(Connection connection) {

        if (connection != null) {

            try {

                connection.close();

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

    /**

     * 关闭发送器statement

     */

    private static void closeStatement(Statement statement) {

        if (statement != null) {

            try {

                statement.close();

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

    /**

     * 关闭连接resultSet

     */

    private static void closeResultSet(ResultSet resultSet) {

        if (resultSet != null) {

            try {

                resultSet.close();

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

    /**

     * 关闭所有连接 connection statement resultSet

     */

    public static void closeAll(Connection connection, Statement statement, ResultSet resultSet) {

        closeResultSet(resultSet);

        closeStatement(statement);

        closeConnection(connection);

    }

}

package testoracle;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import dbutil.JDBUtil;

public class TestDBUtil {

public static void main(String[] args) {

    //声明连接

    Connection connection=null;

    Statement statement=null;

    ResultSet resultSet=null;

    //sql

    String sql="SELECT * FROM EMP";

    try {

    //获取连接

    connection=JDBUtil.createConnection();

    //获取发送器

    statement=JDBUtil.createStatement(connection);

    //发送sql语句

        resultSet=statement.executeQuery(sql);

        while (resultSet.next()) {

            System.out.print(resultSet.getString(1)+"\t");

            System.out.print(resultSet.getString(2)+"\t");

            System.out.print(resultSet.getString(3)+"\t");

            System.out.print(resultSet.getString(4)+"\t");

            System.out.println(resultSet.getString(5)+"\t");

        }

    } catch (SQLException e) {

        // TODO Auto-generated catch block

        e.printStackTrace();

    }finally {

        //关闭连接

        JDBUtil.closeAll(statement, connection, resultSet);

    }

}

}