一只倔强的笨猪

【JAVAEE】JDBC技术运用

1.创建连接数据库的DbConnect类,定义连接数据库的getDBconnection()方法和释放资源的Close()方法。

com/bean/DbConnec.java

package com.bean;

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

public class DbConnect {
	public static Connection getDBconnection() {
		String shujuku = "benzhu";
		String url1 ="jdbc:mysql://localhost:3306/"+shujuku;
		String uname = "root";
		String upwd="123456";
		Connection conn=null;
		try{			
			Class.forName("com.mysql.jdbc.Driver");
			conn= DriverManager.getConnection(url1, uname, upwd);
			System.out.println("哈哈哈哈 连接成功");
		}
		catch(Exception e){
			e.printStackTrace();
		}
		return conn;
	}
	public static void Close(Connection conn,Statement stmt,ResultSet rs) {
		try{if(rs!=null) rs.close();}catch(Exception e){e.printStackTrace();}
		try{if(stmt!=null) stmt.close();}catch(Exception e){e.printStackTrace();}
		try{if(conn!=null) conn.close();}catch(Exception e){e.printStackTrace();}
	}
}

2.创建访问数据库输出用户表信息的servlet类。
conneetion.java

package com.servlet;

import java.io.IOException;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Connection;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bean.DbConnect;



/**
 * Servlet implementation class conneetion
 */
@WebServlet("/conneetion")
public class conneetion extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		try{
			Connection conn;
			conn = DbConnect.getDBconnection();
			Statement stmt = conn.createStatement();
			String sql="select * from benzhu_user";
			ResultSet rs=stmt.executeQuery(sql);
			while(rs.next()) {
				System.out.println(rs.getInt("user_id")+"\t"+rs.getString("user_name")+"\t"+rs.getString("user_pwd"));
				
			}
			DbConnect.Close(conn, stmt, rs);
			
		}
		catch(Exception e){
			e.printStackTrace();
		}
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

3.eclopse记得导入驱动包,代码按照数据库的实际情况稍微改改就ok。

mysql下载地址:https://benzhu.xyz/index.php/2018/03/27/mysql001/

效果图:

《【JAVAEE】JDBC技术运用》

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