JDBC连接数据库工具类（mysql、oracle、sqlserver）

jar包自己准备，此处不罗嗦，直接看代码，简单通俗易懂

package com.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

/**
*
* @ClassName DBUtil
* @Description 数据库工具类
* @author 程军强
* @Date 2017年10月25日 下午9:40:14
* @version 1.0.0
*/
public class DBUtil {

private static final String MYSQL = "jdbc:mysql://";

private static final String ORACLE = "jdbc:oracle:thin:@";

private static final String SQLSERVER = "jdbc:microsoft:sqlserver://";
private DBUtil() {
}

public static Connection getConnection(String DBType, String url,
String user, String password) throws SQLException {
if ("mysql".equalsIgnoreCase(DBType))
return getMySqlConn(url, user, password);
if ("oracle".equalsIgnoreCase(DBType))
return getOracleConn(url, user, password);
if ("sqlserver".equals(DBType)){
return getSqlServerConn(url, user, password);
}
return null;
}

public static void closeConn(Connection conn) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}

private static Connection getMySqlConn(String url, String user,
String password) throws SQLException {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");//加载驱动
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
conn = DriverManager.getConnection(MYSQL + url, "root", "root");

return conn;
}

private static Connection getOracleConn(String url, String user,
String password) throws SQLException {
Connection conn = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");//加载驱动
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
conn = DriverManager.getConnection(ORACLE + url, "scott", "tiger");

return conn;
}

private static Connection getSqlServerConn(String url, String user,
String password) throws SQLException {
Connection conn = null;
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");//加载驱动
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
conn = DriverManager.getConnection(SQLSERVER + url, "root", "root");

return conn;
}

//测试
public static void main(String[] args) {
try {
Connection conn = getConnection("MySQL", "127.0.0.1", "root",
"root");
if (conn == null) {
System.out.println("Connection the database is failled !");
} else {
System.out.println(conn.toString());
}
} catch (SQLException e) {
e.printStackTrace();
}

}

}