jdbc数据库的连接模板

package com.items.util;


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


public class DBHelper {
private static final String driver="com.mysql.jdbc.Driver";//数据库驱动
private static final String url="jdbc:mysql://localhost:3306/items?useUnicode=true&charseterEncoding=UTF-8";
private static final String username="root";//数据库名
private static final String password="root";//数据库密码
    
private static Connection conn=null;
    //静态代码块负责加载驱动
static{
try{
Class.forName(driver);
}
catch(Exception e){
e.printStackTrace();
}
}

//单例模式返回数据库对象
public static Connection getConnection() throws Exception{
if(conn==null){
conn=DriverManager.getConnection(url, username, password);
return conn;

}
return conn;
}
  //检测数据库是否连接正常
  public static void main(String[] args) throws Exception {
Connection conn=DBHelper.getConnection();
if(null!=conn){
System.out.println("数据库连接正常");
}else{
System.out.println("数据库未连接");
}
}


}