Java Web应用优化 认识软件设计分层架构

分层资料的整理

先准备值类和连接数据库的工具类

package week17.entity;

public class User {
	private int id;
	private String uname;
	private String pwd;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getUname() {
		return uname;
	}
	public void setUname(String uname) {
		this.uname = uname;
	}
	public String getPwd() {
		return pwd;
	}
	public void setPwd(String pwd) {
		this.pwd = pwd;
	}
	
	public User(int id, String uname, String pwd) {
		super();
		this.id = id;
		this.uname = uname;
		this.pwd = pwd;
	}
	
	
	
	public User() {
		id=0;
		uname="";
		pwd="";
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", uname=" + uname + ", pwd=" + pwd + ", toString()=" + super.toString() + "]";
	}
	
	
}

package week17.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class BaseDao {
	private final static String driver = "com.mysql.cj.jdbc.Driver";                      // 数据库驱动
	    private final static String url    = "jdbc:mysql://mysql.sqlpub.com:3306/huangjin";   // url
	    private final static String dbName = "laocooon";                                      // 数据库用户名
	    private final static String dbPass = "fc12f7a5215e8e0a";                              // 数据库密码
	    
	    private static Connection        conn  = null;
	    private static PreparedStatement pstmt = null;			        
	    private static ResultSet         rs    = null;

	    public static Connection getConn() throws Exception{
	        Class.forName(driver);                                     //注册驱动
	        return DriverManager .getConnection(url,dbName,dbPass);   //获得数据库连接并返回
	    }
	    public static void closeAll( Connection conn, PreparedStatement pstmt, ResultSet rs ) throws Exception {	        
	        if(rs != null) rs.close();
	        if(pstmt != null) pstmt.close();
	        if(conn != null) conn.close();
	    }
	    
	    public static void closeAll( Connection conn, PreparedStatement pstmt) throws Exception {
	        if(pstmt != null) pstmt.close();
	        if(conn != null) conn.close();
	    }
	    
	    
	    //直接关静态成员的资源
	    public static void closeAll() throws Exception {	        
	    	closeAll(conn,pstmt,rs);// 关 17 18 19行的资源的
	    }
	    
	  //增删改  返回多少条发生了变化，如果0表示没变化
	    public static int executeUpdataSQL(String sql,String[] param)throws Exception {
			Connection        conn  = null;
			PreparedStatement pstmt = null;			        
			
			conn = getConn();                         
			pstmt = conn.prepareStatement(sql);    
			    
			for( int i = 0; i < param.length; i++ ) 
				pstmt.setString(i+1, param[i]);
			
			int num  = pstmt.executeUpdate();
			closeAll(conn,pstmt);
			
			return num;
	    }
	    
	    
	    //调用此代码，使用完 记录集的内容之后，通过  closeAll();
	    public static ResultSet executeQuerySQL(String sql,String[] param)throws Exception {
	    	closeAll();
			conn = getConn();                         
			pstmt = conn.prepareStatement(sql);    
			    
			for( int i = 0; i < param.length; i++ ) 
				pstmt.setString(i+1, param[i]);			
			rs  = pstmt.executeQuery();		
			return rs;
			
	    }
	    
}

数据访问层的类

package week17.dao;

import java.util.List;

import week17.entity.User;

//打算有哪些业务
public interface UserDao {
	public User findUser(String uname) throws Exception;
	public List<User> allUser() throws Exception;
	public int addUser(User user) throws Exception;
}

package week17.dao.impl;

import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import week17.dao.UserDao;
import week17.entity.User;
import week17.util.BaseDao;

public class UserDaoImpl implements UserDao {

	@Override
	public User findUser(String uname) throws Exception {
		// TODO Auto-generated method stub
		String sql="SELECT * FROM adminuser WHERE uname= ?";
		String[] param = {uname};	
		
		ResultSet rs=BaseDao.executeQuerySQL(sql, param);
		User user= new User();
		while(rs.next()) {
			user.setId(rs.getInt(1));
			user.setUname(rs.getString(2));
			user.setPwd(rs.getString(3));
		}
		BaseDao.closeAll();
		rs=null;
		return user;
	}

	@Override
	public List<User> allUser() throws Exception {
		String sql="SELECT * FROM adminuser";
		String[] param = {};		
		
		ResultSet rs=BaseDao.executeQuerySQL(sql, param);		
		List<User> list=new ArrayList<User>();
		while(rs.next()) {
			User user= new User();
			user.setId(rs.getInt(1));
			user.setUname(rs.getString(2));
			user.setPwd(rs.getString(3));
			list.add(user);
		}
		BaseDao.closeAll();
		return list;
	}

	@Override
	public int addUser(User user) throws Exception {
		String sql="INSERT INTO adminuser (uname,pwd) value(?,?)";
		String[] param = {user.getUname(),user.getPwd()};
		int row = BaseDao.executeUpdataSQL(sql, param);
		BaseDao.closeAll();
		return row;
	}
}

业务逻辑层的类

package week17.biz;

import java.util.List;

import week17.entity.User;

public interface UserBiz {
	public boolean login(User user) throws Exception;
	public List<User> getAll() throws Exception;
	public int addUser(User user) throws Exception;
}

package week17.biz.impl;

import java.util.List;

import week17.biz.UserBiz;
import week17.dao.UserDao;
import week17.dao.impl.UserDaoImpl;
import week17.entity.User;

public class UserBizImpl implements UserBiz {

	@Override
	public boolean login(User user) throws Exception {
		UserDao userDao=new UserDaoImpl();
		System.out.println("login");
		User u=userDao.findUser(user.getUname());
		
		return u.getPwd().equals(user.getPwd());
	}

	@Override
	public List<User> getAll() throws Exception {
		// TODO Auto-generated method stub
		UserDao ud=new UserDaoImpl();
		return ud.allUser();
	}

	@Override
	public int addUser(User user) throws Exception {
		
		UserDao ud=new UserDaoImpl();
		String uname=user.getUname();
		User u=ud.findUser(uname);
		return u.getUname().equals(uname)?0:ud.addUser(user);
	}

}

表示层

<%-- dologin.jsp --%>
<%@page import="week17.biz.impl.UserBizImpl"%>
<%@page import="week17.biz.UserBiz"%>
<%@page import="week17.entity.User"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

    
<%
	request.setCharacterEncoding("UTF-8");
	String uname=request.getParameter("username");
	String pwd=request.getParameter("password");
	
	if(uname==null||pwd==null)
		return ;
	
	User u=new User();
	u.setUname(uname);
	u.setPwd(pwd);
	
	UserBiz userBiz=new UserBizImpl();
	if(userBiz.login(u)){
		session.setAttribute("user", u);
		//去管理页
		out.println("登录成功~！");
		response.sendRedirect("./listall.jsp");
	}
	else{
		//去登录页
		response.sendRedirect("./login.jsp");
	}

%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>验证检测</title>
</head>
<body>

</body>
</html>

<%-- listall.jsp --%>
<%@page import="week17.biz.impl.UserBizImpl"%>
<%@page import="week17.biz.UserBiz"%>
<%@page import="week17.entity.User"%>
<%@page import="java.util.*"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    
 <%
 UserBiz ub=new UserBizImpl(); 
 List<User> list=ub.getAll();
 for(User user:list){
	 out.println(user+"<br>");
 }
 
 %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>
</html>

<%-- doadd.jsp --%>
<%@page import="week17.biz.impl.UserBizImpl"%>
<%@page import="week17.biz.UserBiz"%>
<%@page import="week17.entity.User"%>
<%@page import="java.util.*"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    
    
<%
User user=new User(0,"sss1","pwds");
UserBiz ub=new UserBizImpl();

if(ub.addUser(user)>0){
	
	out.println("添加成功");
}else{
	out.println("已经注册过了");
	return ;
}


%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>
</html>