Struts2实现简易登录
使用struts2编写登录demo
工具：
eclipse
tomcat v8.0
struts-2.3.x
顺便附个下载：struts-2.3.29-all.zip
（上个月下载的2.3.28.1，因为S2-037，最新已经是2.3.29了）
1.新建web project
命名后点击next并勾选Generate web.xml
2.导入相关jar包
打开struts-2.3.28.1\apps目录，将struts2-blank.war解压缩，从解压得到的WEB-INF\lib目录获取jar包，添加到新建项目lib中。
3.配置web.xml
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>LoginByStruts2display-name>
<welcome-file-list>
<welcome-file>index.jspwelcome-file>
welcome-file-list>
<filter>
<filter-name>struts2filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilterfilter-class>
filter>
<filter-mapping>
<filter-name>struts2filter-name>
<url-pattern>/*url-pattern>
filter-mapping>
web-app>4.配置struts.xml文件
在src文件夹下面创建strutx.xml文件。
<struts>
<package name="user" extends="struts-default">
<action name="login" class="com.claude.action.Login" method="login">
<result name="success">/success.jspresult>
<result name="input">/index.jspresult>
action>
package>
struts>
5.编写Bean
定义实体类Person
package com.claude.bean;
public class Person {
private String username;
private String password;
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;
}
}
6.编写Dao
模拟登录验证
package com.claude.dao;
import com.claude.bean.Person;
public class Dao {
public boolean isLogin(Person person) {
if (person.getUsername().equals(person.getPassword())) {
return true;
} else {
return false;
}
}
}7.编写Action
LoginAction处理登录的业务逻辑
package com.claude.action;
import com.claude.bean.Person;
import com.claude.dao.Dao;
import com.opensymphony.xwork2.ActionSupport;
public class Login extends ActionSupport{
/**
*
*/
private static final long serialVersionUID = -1339567642215112514L;
private Person person;
public String login(){
Dao dao=new Dao();
boolean flag=dao.isLogin(person);
if(flag){
return SUCCESS;
}else{
return INPUT;
}
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
8.相关JSP
登录界面index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<%-- <%@ taglib prefix="s" uri="/struts-tags"%> --%>
<html>
<head>
<title>Logintitle>
<link href="bootstrap.min.css" rel="stylesheet">
<link href="signin.css" rel="stylesheet">
head>
<body>
<%-- "login" >
"person.username" label="username">
"person.password" label="password">
登录成功success.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head>
<title>success pagetitle>
head>
<body>
Success login. <br>
body>
html>9.运行结果
登录页面
登录成功后
程序目录如下
此demo的struts2工作流程
(用Markdown做的，凑合看……)
Created with Raphaël 2.1.0 开始 访问JSP登录界面index.jsp 提交表单后数据提交到login.action struts2截获所有请求 查找struts.xml，login.action对用Login类 生成一个Login实例，将提交的数据设置到该实例中 根据method设置调用login()方法，否则默认调用实例的 返回SUCCESS 登录成功，访问success.jsp页面 结束 yes no
遇到的一些问题和解决方法
（1）初次配置时，打开JSP出现404。再看控制台，打印出如下错误信息
16:53:04.209 [localhost-startStop-1] ERROR org.apache.struts2.dispatcher.Dispatcher - Dispatcher initialization failed
com.opensymphony.xwork2.config.ConfigurationException: Unable to load configuration.
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70) ~[xwork-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:970) ~[struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:438) ~[struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:482) [struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74) [struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57) [struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279) [catalina.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260) [catalina.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:105) [catalina.jar:8.0.33]
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4658) [catalina.jar:8.0.33]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5277) [catalina.jar:8.0.33]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) [catalina.jar:8.0.33]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408) [catalina.jar:8.0.33]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398) [catalina.jar:8.0.33]
at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_77]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_77]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_77]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_77]
Caused by: com.opensymphony.xwork2.config.ConfigurationException: Cannot locate the chosen ObjectFactory implementation: spring
at org.apache.struts2.config.AbstractBeanSelectionProvider.alias(AbstractBeanSelectionProvider.java:74) ~[struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.config.AbstractBeanSelectionProvider.alias(AbstractBeanSelectionProvider.java:45) ~[struts2-core-2.3.28.1.jar:2.3.28.1]
at org.apache.struts2.config.DefaultBeanSelectionProvider.register(DefaultBeanSelectionProvider.java:363) ~[struts2-core-2.3.28.1.jar:2.3.28.1]
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:240) ~[xwork-core-2.3.28.1.jar:2.3.28.1]
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67) ~[xwork-core-2.3.28.1.jar:2.3.28.1]
... 17 more 不难发现居然在纯struts程序的中出现了spring的字眼，经过排查，发现错误原因是：struts.xml中多了一句
<constant name="struts.objectFactory" value="spring">constant>正常的配置绝对不会出现这种错误，怪就怪自己偷懒，从别处SSH项目里拷过来的配置文件，没改干净就用上了。
初学者一定要自己亲自配置，然后可以和现有项目对比，这样才容易发现细节问题。
（2）也是一个小问题，我在jsp页面中添加CSS时，发现没有起到作用。立即google了一下，按照很多人给出的方法，依次尝试（部分试过的代码已在index.jsp中加以注释），还是无果。不得已把CSS文件放在了程序根目录下。
（3）博客看了不少，从没自己写过。学的越多，越觉得记性不好使，笔记翻不过来，先写一篇非常简单的，算是给自己填补空白。代码过于简单，就不加注释了。研究了一下排版，尚不熟悉。如有看官路过，望多多包涵，不吝赐教。