Java连接MySQL数据库(多种连接方法)

当我们掌握Java的基础知识后就可以学习一些Java的高级技术(或特性)了，例如：集合、多线程、网络编程、数据库技术、并发等等。其中数据库技术在Java的学习中也是相当重要的，今天就简单介绍一下Java与MySQL数据类的

1.提前准备
- 下载并安装MySQL数据库

- 下载并在eclipse中导入Java--MySQL连接器（ODBC）

(两个连接器导入其中任意一个即可)

2.连接数据库

2.1在main方法中连接

package test_connect;
import java.sql.*;
public class test_1_connect {
	private static String driver = "com.mysql.jdbc.Driver";
	private static String url = "jdbc:mysql://127.0.0.1:3306/student_db?useSSL=false";
	private static String user = "root";
	private static String password = "123123";
	
	public static void main(String[] args) {
		Connection conn = null;
		Statement stamt = null;
		ResultSet rs = null;

		try {
			Class.forName(driver);//载入驱动器(即Java-connector-Mysql-bin.jar文件)
			conn = DriverManager.getConnection(url,user, password);
			stamt = conn.createStatement();
			System.out.println("the dataBase connext successful.");
			
			String sql = "SELECT id,name FROM student";
			rs = stamt.executeQuery(sql);
			while(rs.next()) {
				System.out.println(rs.getString("id")+"  "+rs.getString("name"));
			}
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}catch (SQLException e1) {
			e1.printStackTrace();
		}finally {//程序结束关闭连接
			try {
				if(rs != null)rs.close();
				if(stamt != null)stamt.close();
				if(conn != null)conn.close();
			}catch(Exception e2) {
				e2.printStackTrace();
			}
		}		
	}

}

2.2把连接的类当做一个工具类，此处使用单例模式

package tool;

import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;

public class Connect {
	private static String driver;
	private static String url;
	private static String user;
	private static String password;
	private static String db;
	
	private Connection conn;
	private Statement stamt;
	private ResultSet rs;
	
	private static final Connect c = new Connect();
	
	private Connect() {
		driver = "com.mysql.jdbc.Driver";
		url = "jdbc:mysql://127.0.0.1:3306/"+db+"?useSSL=false";
		user = "root";
		password = "123123";
		db="";
	}
	
	public static final Connect getC() {
		return c;
	}
	
	public final void buildConnect() {
		try {
			Class.forName(driver);
			url = "jdbc:mysql://127.0.0.1:3306/"+db+"?useSSL=false";
			password = getPassword();
			c.conn = (Connection) DriverManager.getConnection(url, user, password);
			c.stamt = (Statement) conn.createStatement();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}catch(SQLException e2) {
			e2.printStackTrace();
		}
		System.out.println("buildConnect");
	}
	
	public  final void closeConnect() {
			try {
				if(conn != null)conn.close();
				if(stamt != null)stamt.close();
				if(rs != null)rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		System.out.println("closeConnect");
	}
	
	public static String getDb() {
		return db;
	}
	
	public static void setDb(String db) {
		Connect.db = db;
	}
	
	public static String getPassword() {
		return password;
	}
	
	public static void setPassword(String password) {
		Connect.password = password;
	}
	
	public Connection getConn() {
		return conn;
	}

	public Statement getStamt() {
		return stamt;
	}

	public ResultSet getRs() {
		return rs;
	}
}

总结：Java连接数据库至少设置四项即driver（驱动器），url，user和password，若想在连接后进行操作则必须创建Connection对象，再利用Connection对象创建对话Statement，ResultSet对象通过Statement对象执行SQL语句得到。

ps：一分耕耘一分收获，你付出的努力终有一天会给你回报。

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