建立数据库连接

package net.fzjol.common.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.PropertyResourceBundle;
import java.util.ResourceBundle;

public class DBConn {
private static DBConn conn = null;
private Connection con = null;

// 私有构造方法,使该类不能被实例化
private DBConn() {
}

// 创建该类的一个实例
public synchronized static DBConn getConn() {
if (conn == null) {
conn = new DBConn(); return conn;
}

// 创建数据库连接
public Connection getConnection() {
ResourceBundle rb = PropertyResourceBundle.getBundle("config");
String dataType = rb.getString("dataType");
String driver = rb.getString(dataType + ".driver");
String url = rb.getString(dataType + ".url");
String user = rb.getString(dataType + ".user");
String password = rb.getString(dataType + ".pswd");
try {
Class.forName(driver);// 加载数据库驱动
con = DriverManager.getConnection(url, user, password);// 创建数据库连接
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace(); return con;
}

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config.properties

#db type(oracle,sqlserver,mysql)
dataType = oracle
#db oracle
oracle.driver = oracle.jdbc.driver.OracleDriver
oracle.url    = jdbc:oracle:thin:@172.0.0.1:1521:ORCL
oracle.user   = scott
oracle.pswd   = dbmaster
#db sqlserver
sqlserver.driver = com.microsoft.jdbc.sqlserver.SQLServerDriver
sqlserver.url    = jdbc:microsoft:sqlserver://172.0.0.1:1433; DatabaseName = test
sqlserver.user   = sa
sqlserver.pswd   = dbmaster
#db mysql
mysql.driver = com.mysql.jdbc.Driver
mysql.url    = jdbc:mysql://localhost:3306/test
mysql.user   = root
mysql.pswd   = dbmaster