SSH整合——架构的历史

来源：互联网发布：谢云流正太捏脸数据编辑：程序博客网时间：2024/05/22 11:40

SSH整合——架构的历史1

写一个小项目，用户注册，有register.jsp、registerDeal.jsp、registerSuccess.jsp、registerFail.jsp

A、两层结构

只有JSP页面和数据库

(1)register.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<!--

-->

</head>

<body>

用户名：<input type="text" name="username" /><br/>

密码:<input type="password" name="password" /><br/>

确认密码：<input type="password" name="password2" /><br>

</form>

</body>

</html>

(2)registerDeal.jsp

<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

String username=request.getParameter("username");

String password=request.getParameter("password");

String password2=request.getParameter("password2");

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

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/spring", "root", "root");

String sqlQuery = "select count(*) from user where username= ?";

PreparedStatement psQuery= conn.prepareStatement(sqlQuery);

psQuery.setString(1, username);

ResultSet rs = psQuery.executeQuery();

rs.next();

int count = rs.getInt(1);

if(count > 0){

response.sendRedirect("registerFail.jsp");

psQuery.close();

conn.close();

return;

}

String sql = "insert into user values (null,?,?)";

PreparedStatement ps= conn.prepareStatement(sql);

ps.setString(1, username);

ps.setString(2, password);

ps.executeUpdate();

ps.close();

conn.close();

response.sendRedirect("registerSuccess.jsp");

(3)registerSuccess.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>Success page</title>

<!--

-->

</head>

<body>

Success <br>

</body>

</html>

(4)registerFail.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<!--

-->

</head>

<body>

Fail

</body>

</html>

(5)以上设计的不利的地方在于，jsp页面封装了数据库操作，当其他应用如JavaEE应用需要使用jsp页面中的逻辑时，将导致不变。根据面向对象设计，至少应该有一个实体类User

B、三层结构+Entity+Serice

（1）创建Model层

package com.zgy.registration.model;

public class User {

private String username;

private String password;

private int id;

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

（2）创建service层

package com.zgy.registration.service;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import com.zgy.registration.model.User;

public class UserManager {

public boolean exists(User u) throws SQLException, ClassNotFoundException {

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

Connection conn = DriverManager.getConnection(

"jdbc:mysql://localhost:3306/spring", "root", "root");

String sqlQuery = "select count(*) from user where username= ?";

PreparedStatement psQuery = conn.prepareStatement(sqlQuery);

psQuery.setString(1, u.getUsername());

ResultSet rs = psQuery.executeQuery();

rs.next();

int count = rs.getInt(1);

psQuery.close();

if (count > 0) {

return true;

}

return false;

}

public void add(User u) {

try {

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

Connection conn = DriverManager.getConnection(

"jdbc:mysql://localhost:3306/spring", "root", "root");

String sql = "insert into user values (null,?,?)";

PreparedStatement ps = conn.prepareStatement(sql);

ps.setString(1, u.getUsername());

ps.setString(2, u.getPassword());

ps.executeUpdate();

ps.close();

conn.close();

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (SQLException e) {

e.printStackTrace();

}

（3）修改registerDeal.jsp，访问model层和service层，不再访问数据库

<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>

<%@ page import="com.zgy.registration.model.*" %>

<%@ page import="com.zgy.registration.service.*" %>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

String username=request.getParameter("username");

String password=request.getParameter("password");

String password2=request.getParameter("password2");

User u = new User();

u.setUsername(username);

u.setPassword(password);

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

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/spring", "root", "root");

UserManager um = new UserManager();

boolean exist = um.exists(u);

if(exist){

response.sendRedirect("registerFail.jsp");

return;

}

um.add(u);

response.sendRedirect("registerSuccess.jsp");

（4）不便之处：其中使用到的sql语句不是面向对象的特性，此时可以使用到Hibernate

C、N层结构+Entity+Service+Hibernate

(1)使用Hibernate的Annotation注解实体类

package com.zgy.registration.model;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

@Entity

public class User {

private String username;

private String password;

private int id;

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

@Id

@GeneratedValue

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

(2)Hibernate获取SessionFactory

package com.zgy.registration.util;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.AnnotationConfiguration;

public class HibernateUtil {

private static SessionFactory sf;

static {

sf = new AnnotationConfiguration().configure().buildSessionFactory();

}

public static SessionFactory getSessionFactory() {

return sf;

}

(3)修改UserManager

package com.zgy.registration.service;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import org.hibernate.SessionFactory;

import org.hibernate.classic.Session;

import com.zgy.registration.model.User;

import com.zgy.registration.util.HibernateUtil;

public class UserManager {

public boolean exists(User u) throws SQLException, ClassNotFoundException {

SessionFactory sf = HibernateUtil.getSessionFactory();

Session session = sf.getCurrentSession();

session.beginTransaction();

long count = (Long) session

.createQuery(

"select count(*) from User user "

+ "where user.username= :username")

.setString("username", u.getUsername()).uniqueResult();

session.getTransaction().commit();

if (count > 0) {

return true;

}

return false;

}

public void add(User u) {

SessionFactory sf = HibernateUtil.getSessionFactory();

Session session = sf.getCurrentSession();

session.beginTransaction();

session.save(u);

session.getTransaction().commit();

}

(4)JUnit单元测试

package com.zgy.registration.service;

import static org.junit.Assert.*;

import java.sql.SQLException;

import junit.framework.Assert;

import org.junit.Test;

import com.zgy.registration.model.User;

public class TestUserManager {

@Test

public void testExists() throws SQLException, ClassNotFoundException {

UserManager um = new UserManager();

User u = new User();

u.setUsername("a");

boolean exist = um.exists(u);

Assert.assertEquals(true, exist);

}

@Test

public void testAdd() throws SQLException, ClassNotFoundException {

UserManager um = new UserManager();

User u = new User();

u.setUsername("d");

u.setPassword("d");

boolean exist = um.exists(u);

if(!exist){

um.add(u);

Assert.assertEquals(true, um.exists(u));

}else{

Assert.fail("not added");

}

(5)数据成功入库。

(6)如果想要实现跨数据库平台的设计，需要抽象出UserDAO，封装数据库的操作

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