SSH整合- 2- add service layout

来源：互联网发布：隐写术算法编辑：程序博客网时间：2024/05/19 13:45

从业务里抽出实体类，并添加service层！管理user的业务逻辑。

1. 主要文件

SSH整合- <wbr>2- <wbr>add <wbr>service <wbr>layout

2. registerDeal.jsp

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

<%@ page import="java.sql.Connection"%>

<%@ page import="java.sql.DriverManager"%>

<%@ page import="java.sql.PreparedStatement"%>

<%@ page import="java.sql.SQLException"%>

<%@ page import="com.edu.ssh.model.User"%>

<%@ page import="com.edu.ssh.service.UserManager"%>

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

<html>

<head>

</head>

<body>

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

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

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

User user = new User();

user.setUsername(username);

user.setPassword(password);

UserManager userManager = new UserManager();

// 简单验证，不填其他的复杂逻辑

if (!userManager.exists(user)) {

userManager.insertOneUser(user);

//response.sendRedirect("registerSucess.jsp");

request.setAttribute("username", username);

request.getRequestDispatcher("registerSucess.jsp").forward(request,response);

} else {

//response.sendRedirect("registerFail.jsp");

request.getRequestDispatcher("registerFail.jsp").forward(request,response);

}

</body>

</html>

3. UserManager.java

package com.edu.ssh.service;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import com.edu.ssh.model.User;

public class UserManager {

private static String url ="jdbc:mysql://localhost:3306/ssh";

private static String dbusername = "root";

private static String pw = "mysql123";

public Connection getConnection() {

try {

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

} catch (ClassNotFoundException e1) {

e1.printStackTrace();

}

try {

return DriverManager.getConnection(url, dbusername, pw);

} catch (SQLException e) {

e.printStackTrace();

}

return null;

}

public void closeAll(PreparedStatement pstat, Connection conn){

if (null != null) {

try {

pstat.close();

} catch (SQLException e) {

e.printStackTrace();

}

if (null != conn) {

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

public boolean exists(User user) {

String selectSql = "select count(*) from tb_user whereusername=?";

Connection conn = this.getConnection();

PreparedStatement pstat = null;

try {

pstat = conn.prepareStatement(selectSql);

pstat.setString(1, user.getUsername());

ResultSet rs = pstat.executeQuery();

rs.next();

int count = rs.getInt(1);

if (count > 0) {

return true;

}

} catch (SQLException e) {

e.printStackTrace();

} finally {

this.closeAll(pstat, conn);

}

return false;

}

public void insertOneUser(User user) {

String sql = "insert into tb_user(id, username, password)values(null, ?, ?)";

Connection conn = this.getConnection();

PreparedStatement pstat = null;

try {

pstat = conn.prepareStatement(sql);

pstat.setString(1, user.getUsername());

pstat.setString(2, user.getPassword());

pstat.executeUpdate();

} catch (SQLException e) {

e.printStackTrace();

} finally {

this.closeAll(pstat, conn);

}

4. User.java

package com.edu.ssh.model;

public class User {

private int id;

private String username;

private String password;

public int getId() {

return id;

}

public void setId(int id) {

this.id = 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;

}

5. UserManagerTest

package com.edu.ssh.service;

import static org.junit.Assert.*;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import com.edu.ssh.model.User;

public class UserManagerTest {

private UserManager userManager = null;

@Before

public void setUp() throws Exception {

userManager = new UserManager();

}

@After

public void tearDown() throws Exception {

userManager = null;

}

@Test

public void testExists() {

User user = new User();

user.setUsername("admin");

user.setPassword("admin");

assertTrue("exists() 方法失败了！！",userManager.exists(user));

}

@Test

public void testInsertOneUser() {

User user = new User();

user.setUsername("adminff");

user.setPassword("adminff");

userManager.insertOneUser(user);

assertTrue("insertOneUser() 方法失败了！！",userManager.exists(user));

}

6. 结果

7. UML 图

8. 分析

由于吧把业务逻辑和操作数据库都放在jsp里，使得整个jsp层很混乱，修改维护困难，基本不可重用。由此，我们为了增加灵活性，我们增加了service层专门来管理User的逻辑，数据库的操作。使得jsp仅仅是作为显示。但是在service层不应该直接和数据库操作。如果我想换个数据库我们就要找到连接数据库的代码并修改它，加入我们有很多了service层的类，我们可能就要一个个修改，维护麻烦。一次我们可以考虑在增加一个层--dao层，dao层专门处理数据库我们只在service里调用dao提供的接口就可以了。

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SSH整合-&nbsp;2-&nbsp;add&nbsp;service&nbsp;layout

1. 主要文件

2. registerDeal.jsp

3. UserManager.java

4. User.java

5. UserManagerTest

6. 结果

7. UML 图

8. 分析

SSH整合- 2- add service layout