Java使用JDBC连接数据库

不同数据库需要去官网上面下载对应的驱动jar ,例如MySQL https://dev.mysql.com/downloads/connector/j/

　　properties文件

#MySQL
mysqlDriver:com.mysql.jdbc.Driver
mysqlUrl:jdbc:mysql://localhost:3306/test
mysqlUser:root
mysqlPassword:root

#Oracle
oracleDriver:oracle.jdbc.driver.OracleDriver
oracleUrl:jdbc:oracle:thin@localhost:1521:orcl
oracleUser:username
oraclePassword:password

package com.CommonUtil;

/**
 * JDBC工具类
 * @author Andrew
 */

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class JDBCUtil {
    //可以帮助读取和处理资源文件中的信息
    private static Properties pros = null;        
    //静态代码块,加载config.properties文件
    static {
        pros = new Properties();
        try {
            pros.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("./com/config/config.properties"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 建立MySQL数据库连接
     * @return    java.sql.Connection连接对象
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    public static Connection getMySQLConn() throws ClassNotFoundException, SQLException {
        Class.forName(pros.getProperty("mysqlDriver"));
        return DriverManager.getConnection(pros.getProperty("mysqlUrl"), pros.getProperty("mysqlUser"), 
                pros.getProperty("mysqlPassword"));
    }

    /**
     * 建立Oracle数据库连接
     * @return    java.sql.Connection连接对象
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    public static Connection getOracleConn() throws ClassNotFoundException, SQLException {
        Class.forName(pros.getProperty("oracleDriver"));
        return DriverManager.getConnection(pros.getProperty("oracleUrl"), pros.getProperty("oracleUser"), 
                pros.getProperty("oraclePassword"));
    }
    
    /**
     * 关闭所有的数据库连接
     * @param rs    ResultSet对象
     * @param stmt    Statement对象
     * @param conn    Connection对象
     * @throws SQLException
     */
    public void closeAll(ResultSet rs, Statement stmt, Connection conn) throws SQLException {
        if (rs != null)            
            rs.close();    
        if (stmt != null)         
            stmt.close();    
        if (conn != null)         
            conn.close();    
    }

    //关闭ResultSet结果集
    public void close(ResultSet rs) throws SQLException {
        if (rs != null) {
            rs.close();
        }
    }

    //关闭Statement
    public void close(Statement stmt) throws SQLException {
        if (stmt != null) {
            stmt.close();
        }
    }
    
    //关闭数据库Connection连接对象
    public void close(Connection conn) throws SQLException {
            if (conn != null) {
                conn.close();
            }
    }
}