打通Java与MySQL的桥梁——jdbc

Class.forName("com.mysql.jdbc.Driver");

　　private static final String url = "jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8&useSSL=false"; //数据库地址
　　private static final String usename = "root";
　　private static final String password = "root"; //数据库密码

　　Connection connection = DriverManager.getConnection(URL,USER,PASSWORD);　

Statement statement = connection.createStatement();

ResultSet  resultSet = statement.executeQuery("SELECT * FROM goods;");  //用于执行数据库查询

ResultSet  resultSet = statement.executeUpdate("");//用于执行数据库更新

PreparedStatement pStatement = connection.prepareStatement("");  //编译sql代码
pStatement.execute();  //执行sql代码

package util;

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

public class DBHelper {
	
	private static String driver = "com.mysql.jdbc.Driver";   //数据库驱动
	//连接数据库的URL地址
	private static final String url = "jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8&useSSL=false";
	private static final String usename = "root";
	private static final String password = "root"; //数据库密码
	
	private static Connection connection =null;
	//静态代码块负责加载驱动
	static{//静态块中的代码会优先被执行
		try {
			Class.forName(driver);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	//单例模式返回数据库连接对象
	public static Connection getConnection(){
		if(connection==null){
			try {
				connection = DriverManager.getConnection(url,usename,password);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			return connection;
		}
		return connection;
	}
	public static void main(String[] args) {
		ResultSet resultSet = null;
		try{
		Connection connection = DBHelper.getConnection();
		Statement statement =  connection.createStatement();
		 resultSet = statement.executeQuery("SELECT * FROM goods;");		 
		 while(resultSet.next()){
		System.out.println(resultSet.getString("name"));
		 }
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}