1. Custom interceptor
1. Architecture
2. Interceptor creation
//拦截器:第一种创建方式//拦截器生命周期:随项目的启动而创建,随项目关闭而销毁public class MyInterceptor implements Interceptor{}Copy after login
//创建方式2: 继承AbstractInterceptor -> struts2的体贴//帮我们空实现了init 和 destory方法. 我们如果不需要实现这两个方法,就可以只实现intercept方法public class MyInterceptor2 extends AbstractInterceptor{}Copy after login
//创建方式3:继承MethodFilterInterceptor 方法过滤拦截器//功能: 定制拦截器拦截的方法.// 定制哪些方法需要拦截.// 定制哪些方法不需要拦截public class MyInterceptor3 extends MethodFilterInterceptor{}Copy after login
3. Interceptor api
//放行String result = invocation.invoke();
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//前处理System.out.println("MyInterceptor3 的前处理!");//放行String result = invocation.invoke();//后处理System.out.println("MyInterceptor3 的后处理!");Copy after login
//不放行,直接跳转到一个结果页面//不执行后续的拦截器以及Action,直接交给Result处理结果.进行页面跳转return "success";
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4. Interceptor configuration
<package name="inter" namespace="/" extends="struts-default" ><interceptors><!-- 1.注册拦截器 --><interceptor name="myInter3" class="cn.itcast.a_interceptor.MyInterceptor3"></interceptor><!-- 2.注册拦截器栈 --><interceptor-stack name="myStack"><!-- 自定义拦截器引入(建议放在20个拦截器之前) --><interceptor-ref name="myInter3"><!-- 指定哪些方法不拦截
<param name="excludeMethods">add,delete</param> --> <!-- 指定哪些方法需要拦截 --> <param name="includeMethods">add,delete</param></interceptor-ref><!-- 引用默认的拦截器栈(20个) --><interceptor-ref name="defaultStack"></interceptor-ref></interceptor-stack> </interceptors><!-- 3.指定包中的默认拦截器栈 --><default-interceptor-ref name="myStack"></default-interceptor-ref><action name="Demo1Action_*" class="cn.itcast.a_interceptor.Demo1Action" method="{1}" ><!-- 为Action单独指定走哪个拦截器(栈)
<interceptor-ref name="myStack"></interceptor-ref>--><result name="success" type="dispatcher" >/index.jsp</result></action></package>Copy after login
<!-- 补充知识：定义全局结果集 --><global-results><result name="toLogin" type="redirect" >/login.jsp</result></global-results>
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2. struts2 tags
1. Tag system
## 2.struts2 tag structure
3. Control tags
Prepare Action and then go to jsp to practice struts2 tags 
public class Demo2Action extends ActionSupport {public String execute() throws Exception {
List<String> list = new ArrayList<>();
list.add("tom");
list.add("jerry");
list.add("jack");
list.add("rose");
list.add("hqy");
ActionContext.getContext().put("list", list);return SUCCESS;
}
}Copy after login
Start practicing control tags:
<%@ taglib prefix="s" uri="/struts-tags" %><!-- 遍历标签 iterator --><!-- ------------------------------------- --><s:iterator value="#list" ><s:property /><br></s:iterator><!-- ------------------------------------- --><hr><s:iterator value="#list" var="name" ><s:property value="#name" /><br></s:iterator><!-- ------------------------------------- --><hr><s:iterator begin="1" end="100" step="1" ><s:property />|</s:iterator><!-- ------------------if else elseif------------------- --><hr><s:if test="#list.size()==4">list长度为4!</s:if><s:elseif test="#list.size()==3">list长度为3!</s:elseif><s:else>list不3不4!</s:else>
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4. Data label
<!-- ------------------property 配合ognl表达式页面取值 ------------------- --><hr><s:property value="#list.size()" /><s:property value="#session.user.name" />
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5. Form label
<!-- struts2表单标签 --><!-- 好处1: 内置了一套样式. --><!-- 好处2: 自动回显,根据栈中的属性 --><!-- theme:指定表单的主题
xhtml:默认
simple:没有主题 --><s:form action="Demo3Action" namespace="/" theme="xhtml" ><s:textfield name="name" label="用户名" ></s:textfield><s:password name="password" label="密码" ></s:password><s:radio list="{'男','女'}" name="gender" label="性别" ></s:radio><s:radio list="#{1:'男',0:'女'}" name="gender" label="性别" ></s:radio><s:checkboxlist list="#{2:'抽烟',1:'喝酒',0:'烫头'}" name="habits" label="爱好" ></s:checkboxlist><s:select list="#{2:'大专',1:'本科',0:'硕士'}" headerKey="" headerValue="---请选择---" name="edu" label="学历" ></s:select><s:file name="photo" label="近照" ></s:file><s:textarea name="desc" label="个人简介" ></s:textarea><s:submit value="提交" ></s:submit></s:form>Copy after login
6. Non-form tags
Add error message to action
this.addActionError("我是错误信息 哈哈哈");Copy after login
Remove error message
<s:actionerror/>
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3. Exercise: Login function
## Core code:
Action code:
public class UserAction extends ActionSupport implements ModelDriven<User> {private User user = new User();private UserService us = new UserServiceImpl(); public String login() throws Exception {//1 调用Service 执行登陆操作User u = us.login(user);//2 将返回的User对象放入session域作为登陆标识ActionContext.getContext().getSession().put("user", u);//3 重定向到项目的首页return "toHome";
}
@Overridepublic User getModel() {return user;
}
}Copy after login
Service layer code:
public class UserServiceImpl implements UserService {private UserDao ud = new UserDaoImpl();
@Overridepublic User login(User user) {//打开事务 HibernateUtils.getCurrentSession().beginTransaction();//1.调用Dao根据登陆名称查询User对象User existU = ud .getByUserCode(user.getUser_code());//提交事务 HibernateUtils.getCurrentSession().getTransaction().commit(); if(existU==null){//获得不到=>抛出异常提示用户名不存在throw new RuntimeException("用户名不存在!");
}//2 比对密码是否一致if(!existU.getUser_password().equals(user.getUser_password())){//不一致=>抛出异常提示密码错误throw new RuntimeException("密码错误!");
}//3 将数据库查询的User返回return existU;
}
}Copy after login
Dao layer code:
public class UserDaoImpl implements UserDao {
@Overridepublic User getByUserCode(String user_code) {//HQL查询//1.获得SessionSession session = HibernateUtils.getCurrentSession();//2 书写HQLString hql = "from User where user_code = ? ";//3 创建查询对象Query query = session.createQuery(hql);//4 设置参数query.setParameter(0, user_code);//5 执行查询User u = (User) query.uniqueResult();return u;
}
}Copy after login
IV. Exercise: Verify login interception Device
Core code:
Struts.xml configuration file code:
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd"><struts><!-- 指定struts2是否以开发模式运行
1.热加载主配置.(不需要重启即可生效)
2.提供更多错误信息输出,方便开发时的调试 --><constant name="struts.devMode" value="true"></constant><package name="crm" namespace="/" extends="struts-default" ><interceptors><!-- 注册拦截器 --><interceptor name="loginInterceptor" class="cn.itheima.web.interceptor.LoginInterceptor"></interceptor><!-- 注册拦截器栈 --><interceptor-stack name="myStack"><interceptor-ref name="loginInterceptor"><param name="excludeMethods">login</param></interceptor-ref><interceptor-ref name="defaultStack"></interceptor-ref></interceptor-stack></interceptors><!-- 指定包中的默认拦截器栈 --><default-interceptor-ref name="myStack"></default-interceptor-ref><!-- 定义全局结果集 --><global-results><result name="toLogin" type="redirect" >/login.jsp</result></global-results><global-exception-mappings><!-- 如果出现java.lang.RuntimeException异常,就将跳转到名为error的结果 --><exception-mapping result="error" exception="java.lang.RuntimeException"></exception-mapping></global-exception-mappings>
<action name="CustomerAction_*" class="cn.itheima.web.action.CustomerAction" method="{1}" ><result name="list" >/jsp/customer/list.jsp</result><result name="toList" type="redirectAction"> <param name="actionName">CustomerAction_list</param> <param name="namespace">/</param> </result></action><action name="UserAction_*" class="cn.itheima.web.action.UserAction" method="{1}" ><result name="toHome" type="redirect" >/index.htm</result><result name="error" >/login.jsp</result></action></package></struts>Copy after login
Supplementary knowledge: Check whether the parent page of the current page is itself, not If so, jump to solve the page nesting problem.
<script type="text/javascript">window.onload=function(){ if(window.parent != window){// 如果是在框架中//就让框架页面跳转到登陆页面window.parent.location.href = "${pageContext.request.contextPath}/login.jsp";
}
};</script>Copy after login
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