目录

一、maven简介

二，官网下载 

 http://maven.apache.org/download.cgi

三，配置Maven

         配置环境变量

三、eclipse中配置maven

1、点击window->perferences

四、案例

1.实体类

2、dao方法

3、action层

4、util包

哈喽~~大家好！结束了我们会议OA项目之后，我们这期给大家分一个构建工具！！

一、maven简介

    Apache Maven是个项目管理和自动构建工具，基于项目对象模型（POM）的概念。
作用：完成项目的相关操作，如：编译，构建，单元测试，安装，网站生成和基于Maven部署项目。
xxx.class
百度—>xxx.jar
在百度上进行下载
将xxx.jar导入工程中
私服
工程中的某一个xml文件中写入一个字符串，达到jar下载的作用

二，官网下载 

 http://maven.apache.org/download.cgi

我们进入官网之后

 去选择下载先对应的压缩包

下载之后放入非中文目录下面进行解压

三，配置Maven

         配置环境变量

选择此电脑，右键属性，打开系统：

选择高级系统

 选择环境变量

这里按以下图片操作即可

 

三、eclipse中配置maven

1、点击window->perferences

点击add后点击Directory，找到安装maven的根目录即可

四、案例

1.实体类

package com.zking.entity;

public class User {
    private Long id;

    private String name;

    private String loginName;

    private String pwd;

    private Long rid;

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getLoginName() {
		return loginName;
	}

	public void setLoginName(String loginName) {
		this.loginName = loginName;
	}

	public String getPwd() {
		return pwd;
	}

	public void setPwd(String pwd) {
		this.pwd = pwd;
	}

	public Long getRid() {
		return rid;
	}

	public void setRid(Long rid) {
		this.rid = rid;
	}

	public User() {
		super();
		// TODO Auto-generated constructor stub
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", loginName=" + loginName + ", pwd=" + pwd + ", rid=" + rid + "]";
	}
    
    
}

2、dao方法

package com.zking.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import com.zking.entity.User;
import com.zking.util.DBAccess;
import com.zking.util.DBHelper;

public class UserDao {
//	登录
	public User login(User u){
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con=DBAccess.getConnection();
			String sql="select * from t_oa_user where loginName=? and pwd=?";
			ps = con.prepareStatement(sql);
			ps.setString(1, u.getLoginName());
			ps.setString(2, u.getPwd());
			rs=ps.executeQuery();
			if(rs.next()) {
				u.setId(rs.getLong(1));
				u.setName(rs.getString(2));
				u.setLoginName(rs.getString(3));
				u.setPwd(rs.getString(4));
				u.setRid(rs.getLong(5));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBHelper.close(con, ps, rs);
		}
		
		return u;
	}
}

3、action层

package com.zking.web;

import java.io.IOException;
import java.io.PrintWriter;

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.zking.dao.UserDao;
import com.zking.entity.User;

@WebServlet("/login.do")
public class UserAction extends HttpServlet{
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//设置编码方式
		req.setCharacterEncoding("utf-8");
		resp.setCharacterEncoding("utf-8");
		resp.setContentType("text/html; charset=UTF-8");
				
		//拿out
		PrintWriter out = resp.getWriter();
				
		UserDao ud=new UserDao();
		//接收表单传值
		String sname = req.getParameter("name");
		String pwd = req.getParameter("pwd");
		User u=new User();
		u.setLoginName(sname);
		u.setPwd(pwd);
		User u1 = ud.login(u);
		if(u1!=null) {
			out.print("");
		}else{
			out.print("");
		}
	}
}

4、util包

①DBHelper

package com.zking.util;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;


public class DBHelper {
	private static String driver;
	private static String url;
	private static String user;
	private static String password;

	static {// 静态块执行一次，加载 驱动一次
		try {
			InputStream is = DBHelper.class
					.getResourceAsStream("config.properties");

			Properties properties = new Properties();
			properties.load(is);

			driver = properties.getProperty("driver");
			url = properties.getProperty("url");
			user = properties.getProperty("user");
			password = properties.getProperty("pwd");

			Class.forName(driver);
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}

	
	public static Connection getConnection() {
		try {
			Connection conn = DriverManager.getConnection(url, user, password);
			return conn;
		} catch (SQLException e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}

	public static void close(ResultSet rs) {
		if (null != rs) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
				throw new RuntimeException(e);
			}
		}
	}

	public static void close(Statement stmt) {
		if (null != stmt) {
			try {
				stmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
				throw new RuntimeException(e);
			}
		}
	}

	public static void close(Connection conn) {
		if (null != conn) {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
				throw new RuntimeException(e);
			}
		}
	}
	
	public static void myClose(Connection con,PreparedStatement ps,ResultSet rs) {
		try {
			if(rs!=null) {
				rs.close();
			}
			if(ps!=null) {
				ps.close();
			}
			if(con!=null&&!con.isClosed()) {
				con.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void close(Connection conn, Statement stmt, ResultSet rs) {
		close(rs);
		close(stmt);
		close(conn);
	}

	public static boolean isOracle() {
		return "oracle.jdbc.driver.OracleDriver".equals(driver);
	}

	public static boolean isSQLServer() {
		return "com.microsoft.sqlserver.jdbc.SQLServerDriver".equals(driver);
	}
	
	public static boolean isMysql() {
		return "com.mysql.jdbc.Driver".equals(driver);
	}

	public static void main(String[] args) {
		Connection conn = DBHelper.getConnection();
		DBHelper.close(conn);
		System.out.println("isOracle：" + isOracle());
		System.out.println("isSQLServer：" + isSQLServer());
		System.out.println("isMysql：" + isMysql());
		System.out.println("数据库连接(关闭)成功");
	}
}

②config.peoperties

#oracle9i
#driver=oracle.jdbc.driver.OracleDriver
#url=jdbc:oracle:thin:@localhost:1521:ora9
#user=test
#pwd=test


#sql2005
#driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#url=jdbc:sqlserver://localhost:1423;DatabaseName=test
#user=sa
#pwd=sa


#sql2000
#driver=com.microsoft.jdbc.sqlserver.SQLServerDriver
#url=jdbc:microsoft:sqlserver://localhost:1433;databaseName=unit6DB
#user=sa
#pwd=888888

#mysql5
#driver=com.mysql.jdbc.Driver
#url=jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT
#user=mybatis_ssm
#pwd=xiaoli

#mysql8
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/t280?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true
user=root
pwd=123456

运行结果：