使用 MySQL 将 web java 连接到数据库系统

Question

我创建了一个带有登录信息帐户（用户名、密码）的 java 网站。现在我想使用 MySQL ver5.6 连接到数据库。我已经有了 ID、用户名、密码的数据库。

package dao;

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


public abstract class DBConnectionDAO {

/** Connection */
protected Connection connection;

/** className */
private String className = "com.mysql.jdbc.Driver";

/** stringConnection */
private String stringConnection = "jdbc:mysql://localhost/test?user=root&password=abc123&characterEncoding=UTF-8";

/**
 * @Constructor Phuong thuc khoi tao
 */
public DBConnectionDAO() {
    try {
        Class.forName(className);
        // Open connection
        connection = DriverManager.getConnection(stringConnection);
    } catch (ClassNotFoundException e) {
        System.err.println("Class not found! Please review your library");
    } catch (SQLException e) {
        e.printStackTrace();
        System.err.println("Loi truy van");
    }
}

}

Answer 1

公共类数据库{

Connection conn = null;
int id;

static{
    try {
        Class.forName("com.mysql.jdbc.Driver");
        System.out.println("Driver Loaded Successfully..");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
        }
    }

public Connection connect(){
    try {
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/databasename", "root", "root");
        if(conn!=null)
        {
            System.out.println("Database Connected Successfully...");
        }

    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return conn;

}