SSH学习笔记(二)

二、小项目实践

项目描述：对一个用户的姓、名、年龄进行增删查改，使用ssh框架 + apache的dbcp连接池。

1、确认commons-dbcp.jar已被导入(按照上篇的操作，则会被导入)

2、使用mysql数据库，建立名为mytest的数据库，创建表users

create table users (
id int not null,
firstname varchar(50) not null,
lastname varchar(50) not null,
age int not null,
primary key (id)
) ENGIN = InnoDB ROW_FORMAT = DEFAULT;

3、入口网页index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>         <!--  增加页面的structs支持 -->

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    
    <title>My JSP 'index.jsp' starting page</title>

  </head>
  
  <body>
    <h1><font color="red">Operation List</font>
    </h1>
    
    <s:a href="save.jsp">Save User</s:a><br><br><br>
    <!--  structs提供的标签 -->
    <s:a href="listUser.action"> List User</s:a>
    <!--  通过调用服务器端的资源来显示所有用户 -->
  </body>
</html>

4、新建save.jsp，保存用户页面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>

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

    <title>save user</title>

  </head>
  
  <body>
       <h1><font color="red">Save User</font>
    </h1>
    
    <s:form action="saveUser">
    <s:textfield name="user.firstname" label="firstname"></s:textfield>
     <s:textfield name="user.lastname" label="lastname"></s:textfield>
     <s:textfield name="user.age" label="age"></s:textfield>
     <s:submit></s:submit>
     </s:form>
  </body>
</html>

5、新建包com.test.bean，在其中新建User.java

package com.test.bean;

public class User {
	private Integer id;
	private String firstname;
	private String lastname;
	private int age;

	public Integer getId() {
		return id;
	}

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

	public String getFirstname() {
		return firstname;
	}

	public void setFirstname(String firstname) {
		this.firstname = firstname;
	}

	public String getLastname() {
		return lastname;
	}

	public void setLastname(String lastname) {
		this.lastname = lastname;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}
}

这个javabean就好了。然后生成与之对应的hibernate配置文件。在相同的包里新建User.hbm.xml

<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

</hibernate-mapping>

6、新建包com.test.action.user，在包中新建SaveUserAction.java

package com.test.action.user;

import com.opensymphony.xwork2.ActionSupport;
import com.test.bean.User;
import com.test.service.UserService;

public class SaveUserAction extends ActionSupport {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private User user;
	private UserService service;

	public User getUser() {
		return user;
	}

	public void setUser(User user) {
		this.user = user;
	}

	@Override
	public String execute() throws Exception {
		// TODO Auto-generated method stub
		//不自己实现保存用户，而是调用业务逻辑层来实现
		this.service.save(this.user);
		return this.SUCCESS;
	}

	public UserService getService() {
		return service;
	}

	public void setService(UserService service) {
		this.service = service;
	}
	
	
}

7、为页面添加国际化支持。在src目录下新建文件struts.properties，在文件中写上

struts.custom.i18n.resources=globalMessages

在src目录下新建globalMessages_en.properties，在文件中写上

firstname=firstname
lastname=lastname
age=age

在src目录下新建globalMessages_zh.properties，添加对应关系，在文件中写上(这里用图形化操作比较好)

firstname=\u59D3
lastname=\u540D
age=\u5E74\u9F84

即firstname对应“姓”，lastname对应“名”，age对应“年龄”。

修改save.jsp，将label属性改一下，修改后为

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>

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

    <title>save user</title>

  </head>
  
  <body>
       <h1><font color="red">Save User</font>
    </h1>
    
    <s:form action="saveUser">
    <s:textfield name="user.firstname" label="%{getText('firstname')}"></s:textfield>
     <s:textfield name="user.lastname" label="%{getText('lastname')}"></s:textfield>
     <s:textfield name="user.age" label="%{getText('age')}"></s:textfield>
     <s:submit></s:submit>
     </s:form>
  </body>
</html>

这样，save.jsp就有了国际化的支持了。

8、新建包com.test.dao，在包中新建UserDAO.java

package com.test.dao;

import java.util.List;

import com.test.bean.User;

public interface UserDAO {

	public void saveUser(User user);
	
	public void removeUser(User user);
	
	public User findUserById(Integer id);
	
	public List<User> findAllUsers();
	
	public void updateUser(User user);
}

9、新建包com.test.dao.impl，在包中新建UserDAOImpl.java

package com.test.dao.impl;

import java.util.List;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.test.bean.User;
import com.test.dao.UserDAO;

public class UserDAOImpl extends HibernateDaoSupport implements UserDAO {

	@SuppressWarnings("unchecked")
	public List<User> findAllUsers() {
		// 根据hql查询
		//@SuppressWarnings("unchecked")
		String hql = "from User user order by user.id desc";
		return (List<User>)this.getHibernateTemplate().find(hql);
	}

	public User findUserById(Integer id) {
		// TODO Auto-generated method stub
		User user = (User)this.getHibernateTemplate().get(User.class, id);
		return user;
	}

	public void removeUser(User user) {
		// TODO Auto-generated method stub
		this.getHibernateTemplate().delete(user);
	}

	public void saveUser(User user) {
		// TODO Auto-generated method stub
		this.getHibernateTemplate().save(user);
	}

	public void updateUser(User user) {
		// TODO Auto-generated method stub
		this.getHibernateTemplate().update(user);
	}

}

10、新建包com.test.service，在包中新建UserService.java

package com.test.service;

import java.util.List;

import com.test.bean.User;

public interface UserService {

	public List<User> findAll();
	
	public void save(User user);
	
	public void delete(User user);
	
	public User findById(Integer id);
	
	public void update(User user);
}

11、新建包com.test.service.impl，在包中新建UserServiceImpl.java

package com.test.service.impl;

import java.util.List;

import com.test.bean.User;
import com.test.dao.UserDAO;
import com.test.service.UserService;

public class UserServiceImpl implements UserService {

	private UserDAO userDao;
	
	
	public void delete(User user) {
		// TODO Auto-generated method stub
		this.userDao.removeUser(user);
	}

	public List<User> findAll() {
		// TODO Auto-generated method stub
		return this.userDao.findAllUsers();
	}

	public User findById(Integer id) {
		// TODO Auto-generated method stub
		return this.userDao.findUserById(id);
	}

	public void save(User user) {
		// TODO Auto-generated method stub
		this.userDao.saveUser(user);
	}

	public void update(User user) {
		// TODO Auto-generated method stub
		this.userDao.updateUser(user);
	}

	public UserDAO getUserDao() {
		return userDao;
	}

	public void setUserDao(UserDAO userDao) {
		this.userDao = userDao;
	}

}

12、编辑structs.xml，添加action的信息

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
	<package name="user" extends="struts-default">
		<action name="saveUser" class="saveUserAction">
			<result name="success" type="redirect">listUser.action</result> <!-- 输入正确的话跳转到另一个action -->
			<result name="input">/saveUser.jsp</result>  <!-- 输入错误的话跳就在saveUser.jsp页面继续输入 -->
		</action>
	</package>

</struts>

13、这时如果打开tomcat，会报错，Action class [saveUserAction] not found，这时因为我们的structs.xml里面配置的是一个别名，这个别名是由Spring来为我们提供的，但是这个Spring的配置文件我们还没编写。

14、把mysql-connector-java-5.0.3-bin.jar连接器拷贝到项目的lib目录下，编辑/WebRoot/WEB-INF/applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
	xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

<!-- 整个文件是一层一层注入，从数据源注入到sessionFactory，然后从sessionFactory注入到dao -->

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"> <!-- 配置数据库连接池 -->
	<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
	<property name="url" value="jdbc:mysql://localhost:3306/mytest"></property>
	<property name="username" value="root"></property>
	<property name="password" value="moiyer"></property>
	<property name="maxActive" value="100"></property>
	<property name="maxIdle" value="30"></property>
	<property name="maxWait" value="500"></property>
	<property name="defaultAutoCommit" value="true"></property> <!-- 本项目中的操作不需要事务，都是原子性的 -->
</bean> 

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
	<property name="dataSource" ref="dataSource"></property>
	<property name="hibernateProperties">
		<props>
			<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
			<prop key="hibernate.show_sql">true</prop>
		</props>
	</property>
	<property name="mappingResources">
		<list>
			<value>com/test/bean/User.hbm.xml</value><!-- 即包com.test.bean下的User.hbm.xml -->
		</list>
	</property>
</bean>

<bean id="userDao" class="com.test.dao.impl.UserDAOImpl" scope="singleton"> <!-- 这个singleton与设计模式里的singleton模式不同 -->
	<property name="sessionFactory">
		<ref bean="sessionFactory"/>
	</property>	
</bean>

<bean id="userService" class="com.test.service.impl.UserServiceImpl">
	<property name="userDao" ref="userDao"></property>
</bean>

<bean id="saveUserAction" class="com.test.action.user.SaveUserAction">
	<property name="service" ref="userService"></property>
</bean>
</beans>

这时打开tomcat，会报错，Error creating bean with name 'sessionFactory' defined in...这是因为myeclipse为我们自动导入包的时候造成了包冲突，删除lib目录下的asm-2.2.3.jar即可解决。

15、到现在为止，项目的ssh框架已经完全整合起来了。打开tomcat,访问http://localhost:8080/mytest/index.jsp，保存用户，不论中英文都可以在数据库中保存（将字符集设置成utf-8比较好：将页面pagecoding设置成utf-8，将structs设置成utf-8（默认已如此），将mysql设置成utf-8）。这时保存用户提交后页面会跳转到一个无法访问的页面，这是因为这个页面我们还没有写，但是可以从数据库看是否成功。

16、在包com.test.action.user中新建ListUserAction.java

package com.test.action.user;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.test.service.UserService;

public class ListUserAction extends ActionSupport {

	@Override
	public String execute() throws Exception {
		// TODO Auto-generated method stub
		Map request = (Map) ActionContext.getContext().get("request");
		request.put("list", service.findAll());
		return SUCCESS;
	}

	private UserService service;

	public UserService getService() {
		return service;
	}

	public void setService(UserService service) {
		this.service = service;
	}
}

在structs.xml中加上listuser的action

		<action name="listUser" class="listUserAction">
			<result>/list.jsp</result> <!-- 直接跳到list.jsp -->
		</action>

在applicationContext.xml中加上listuser的bean

<bean id="listUserAction" class="com.test.action.user.ListUserAction">
	<property name="service" ref="userService"></property>
</bean>

17、在WebRoot中新建list.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>         <!--  增加页面的structs支持 -->

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    
    <title>list page</title>

  </head>
  
  <body>
    <h1><font color="red">User List</font>
    </h1>
    
    <table border="1" align="center"><!-- 删除和更新操作以后再实现 -->
		<tr>
			<td>id
			</td>
			<td>姓
			</td>
			<td>名
			</td>
			<td>年龄
			</td>
			<td>删除
			</td>
			<td>更新
			</td>
		</tr> 
		<s:iterator value="#request.list" id="us">
			<tr>
				<td><s:property value="#us.id"/>
				</td>
				<td><s:property value="#us.firstname"/>
				</td>
				<td><s:property value="#us.lastname"/>
				</td>
				<td><s:property value="#us.age"/>
				</td>
				<td><s:a href="deleteUser.action?user.id=%{#us.id}">delete</s:a>
				<td><s:a href="updatePUser.action?user.id=%{#us.id}">update</s:a>
				</td>
			</tr>
		</s:iterator>  
		 
    </table>
  </body>
</html>

18、重新打开tomcat，进行插入用户操作，操作成功。自此，这个小项目基本完成。

19、添加输入校验信息。有两种方法：(1)、使用在action的validate方法中进行输入信息的校验。(2)、使用模型驱动来进行校验，基于structs2校验框架。第一种方法比较容易理解，下面使用第二种方法来实现。有2种校验方式，方法1）编写校验文件：在包com.test.action.user包中新建SaveUserAction-validation.xml（注意名字一定为这个）

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

<validators>
	<field name="user.firstname"> 
		<field-validator type="requiredstring">
			<message>required first name</message>
		</field-validator>
	</field>
	
	<field name="user.lastname">
		<field-validator type="requiredstring">
			<message>required last name</message>
		</field-validator>
	</field>
	
	<field name="user.age">
		<field-validator type="required">
			<message>required age</message>
		</field-validator>
		<field-validator type="int">
			<param name="min">1</param>
			<param name="max">150</param>
			<message>age should be between ${min} and ${max}</message>
		</field-validator>
	</field>
	
</validators>

方法2）在包com.test.action.user包中新建SaveUserAction-validation.xml（注意名字一定为这个）

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

<validators>
	<field name="user">
		<field-validator type="visitor">        <!-- visitor类型表示通过另外一个配置文件对user的属性进行校验 -->
			<param name="context">user</param>   <!-- 与实际校验文件的名字有关，“类名-user-validation” -->
			<param name="appendPrefix">true</param>  <!-- 几个提示信息的前缀相同，都为user's -->
			<message>user's </message>
		</field-validator>
	</field>
</validators>

在com.test.bean包中新建校验文件User-user-validation.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

<validators>
	<field name="firstname">
		<field-validator type="requiredstring">
			<message>required first name</message>
		</field-validator>
	</field>

	<field name="lastname">
		<field-validator type="requiredstring">
			<message>required last name</message>
		</field-validator>
	</field>

	<field name="age">
		<field-validator type="required">
			<message>required age</message>
		</field-validator>
		<field-validator type="int">
			<param name="min">1</param>
			<param name="max">150</param>
			<message>age should be between ${min} and ${max}</message>
		</field-validator>
	</field>

</validators>

20、好了，校验框架完成了。但是如果第一次输入的数据错误，点提交报错后，再填错误的信息提交，但是输出的错误消息会叠加，这显然是错误的。对于使用structs2.0管理的项目，请求来了之后，actionservelet会创建一个action，不会出现这个错误。但是我们的项目是由spring管理的，action是由bean工厂来创建的，默认是单例的，即使用创建的一个action来处理所有的用户请求，所以就会出现上述错误。解决方法是修改applicationContext.xml的action申明

<bean id="saveUserAction" class="com.test.action.user.SaveUserAction" scope="prototype">   <!-- scope保证对于每一个新的请求，会创建一个新的action来处理 -->
	<property name="service" ref="userService"></property>
</bean>

<bean id="listUserAction" class="com.test.action.user.ListUserAction"  scope="prototype">
	<property name="service" ref="userService"></property>
</bean>

21、删除用户功能。在包com.test.action.user中新建RemoveUserAction.java

package com.test.action.user;

import com.opensymphony.xwork2.ActionSupport;
import com.test.bean.User;
import com.test.service.UserService;

public class RemoveUserAction extends ActionSupport
{
	private User user;
	private UserService service;
	
	public User getUser()
	{
		return user;
	}
	public void setUser(User user)
	{
		this.user = user;
	}
	public UserService getService()
	{
		return service;
	}
	public void setService(UserService service)
	{
		this.service = service;
	}
	
	@Override
	public String execute() throws Exception
	{
		this.service.delete(user);
		
		return SUCCESS;
	}
	
}

在structs.xml中添加action的声明

<action name="deleteUser" class="removeUserAction">
	<result name="success" type="redirect">listUser.action</result>
</action>

在applicationContext.xml中添加action的声明

<bean id="removeUserAction" class="com.test.action.user.RemoveUserAction" scope="prototype">
	<property name="service" ref="userService"></property>
</bean>

好了，项目的删除功能已经完成了。
22、完成更新功能。在包com.test.action.user中新建UpdatePUserAction.java这个action进行更新预处理

package com.test.action.user;

import com.opensymphony.xwork2.ActionSupport;
import com.test.bean.User;
import com.test.service.UserService;

public class UpdatePUserAction extends ActionSupport
{
	private User user;
	private UserService service;
	
	public User getUser()
	{
		return user;
	}
	public void setUser(User user)
	{
		this.user = user;
	}
	public UserService getService()
	{
		return service;
	}
	public void setService(UserService service)
	{
		this.service = service;
	}
	
	@Override
	public String execute() throws Exception
	{
		user = this.service.findById(user.getId());    //两个user不是一样的
		
		return SUCCESS;
	}
}

在structs.xml中添加action的声明

<action name="updatePUser" class="updatePUserAction">
		<result name="success">/update.jsp</result>
</action>

在applicationContext.xml中添加action的声明

<bean id="updatePUserAction" class="com.test.action.user.UpdatePUserAction" scope="prototype">
	<property name="service" ref="userService"></property>
</bean>

在WebRoot下新建update.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%
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>
    <base href="<%=basePath%>">
    
    <title>My JSP 'update.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
    
    <h1><font color="red">Update User</font></h1>
    
    <s:form action="updateUser">
    	
    	<table>
    		<tr>
    			<td>
    				<s:hidden name="user.id" value="%{user.id}"></s:hidden>  <!-- 将id设为不显示，但是还是会提交 -->
    			</td>
    		</tr>
    		
    		<tr>
    			<td>
    				<s:textfield name="user.firstname" value="%{user.firstname}" label="%{getText('firstname')}"></s:textfield>
    			</td>
    		</tr>
    		
    		<tr>
    			<td>
    				<s:textfield name="user.lastname" value="%{user.lastname}" label="%{getText('lastname')}"></s:textfield>
    			</td>
    		</tr>
    		
    		<tr>
    			<td>
    				<s:textfield name="user.age" value="%{user.age}" label="%{getText('age')}"></s:textfield>
    			</td>
    		</tr>
    		
    		<tr>
    			<td>
    				<s:submit></s:submit>
    			</td>
    		</tr>
    	</table>
    	
    </s:form>
    
  </body>
</html>

在包com.test.action.user中新建UpdateUserAction.java这个action真正进行更新

package com.test.action.user;

import com.opensymphony.xwork2.ActionSupport;
import com.test.bean.User;
import com.test.service.UserService;

public class UpdateUserAction extends ActionSupport
{
	private User user;
	private UserService service;

	public User getUser()
	{
		return user;
	}

	public void setUser(User user)
	{
		this.user = user;
	}

	public UserService getService()
	{
		return service;
	}

	public void setService(UserService service)
	{
		this.service = service;
	}
	
	@Override
	public String execute() throws Exception
	{
		this.service.update(user);
		
		return SUCCESS;
	}

}

在structs.xml中添加action的声明

<action name="updateUser" class="updateUserAction">
	<result name="success" type="redirect">listUser.action</result>
	<result name="input">/update.jsp</result>
</action>

在applicationContext.xml中添加action的声明

<bean id="updateUserAction" class="com.test.action.user.UpdateUserAction" scope="prototype">
	<property name="service" ref="userService"></property>
</bean>

输入校验，在包com.test.user.action中新建UpdateUserAction-validation.xml，内容与SaveUserAction-validation.xml相同。

到此，更新功能已经完成。

SSH学习笔记(二)

Nginx R31 doc 官方文档-01-nginx 如何安装

Qt/C++音视频开发74-合并标签图形/生成yolo运算结果图形/文字和图形合并成一个/水印滤镜

挑战程序设计竞赛 2.2章习题 POJ - 3617 Best Cow Line 贪心

字节面试：MySQL什么时候锁表？如何防止锁表？

.NET8连接SQL SERVER 2008 R2 报：证书链是由不受信任的颁发机构颁发的

golang开发环境搭建(win10)

python计算机视觉学习笔记——PIL库的用法

Golang初学：获取程序内存使用情况，std runtime

設計模式之(二十一)訪問者模式Visitor

SSH學習筆記(二)

Eclipse 項目有紅感嘆號、小紅叉

android模擬器快捷鍵（對使用模擬器開發很有用）

設計模式之(十八)策略模式Strategy

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結