11级_Java_曹建波 03.02 Struts2_事物管理&文件上传-优快云博客

在实现登陆后对admin的增删改查的操作中。

http客户端------------->web容器----->struts2过滤器-

------>struts.xml--->Action----service-->dao->J数据库

登陆

Action中验证用户是否登陆成功

Adminentity;getEntity(){returnentity;};//request

返回到客户段：

sc.jsp页面${entity.adminName}

用户管理

----->查询所有的用户信息

Admin_list.jsp${entity.adminName}

Servlet

session.setAttribute(“entity”,entity);

Application:

服务器端：会话的集合

Session:

什么是一个会话?

从你打开IE浏览器开始----退出

就是一个会话。

Request

请求-------〉

《-------------------响应

Page:

当前页面

高内聚低耦合

Struts2：访问或添加request/session/application属性

通过前面的练习大家都知道，在action的方法中与servlet的所有的API是没有任何关系的。所以在struts2中做到了aciton与serlvet的松耦合，这点是非常强大的。但是如果没有HttpServletRequest,HttpServletSession,ServletContext有些功能是没有办法完成的。比如购物车程序，需要把购买的物品放入session中。所以就得找一些路径使得在struts2中和serlvet的API相结合。

Struts2ActionContextMap

publicStringscope()throwsException{

ActionContextctx=ActionContext.getContext();

ctx.getApplication().put("app","应用范围");//往ServletContext里放入app

ctx.getSession().put("ses","session范围");//往session里放入ses

ctx.put("req","request范围");//往request里放入req

return"scope";

}

JSP:

<body>

${applicationScope.app}<br>

${sessionScope.ses}<br>

${requestScope.req}<br>

</body>

HttpServletRequestHttpSessionServletContext

Requestsessionapplication

request.setAttribute(“name”，value);

${requestScope.name}

session.setAttribute(“name”,value);

${sessionScope.name}

application

ServletContextapplication=getServletContext();

application.setAttribute(“name”,value);

${application.name}

Struts2servlet松耦合

获取HttpServletRequest/HttpSession/ServletContext/HttpServletResponse对象

方式一：

ServletActionContext调用ServletAPI

//Struts2中提供ServletActionContext

//request

HttpServletRequestrequest=ServletActionContext.getRequest();

request.setAttribute("user",user);

//session

HttpSessionsession=request.getSession();

session.setAttribute("user",user);

//application

ServletContextapplication=ServletActionContext.getServletContext();

application.setAttribute("user",user);

方式二：实现几个接口

packagewww.csdn.struts_scope.action;

importjavax.servlet.ServletContext;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importjavax.servlet.http.HttpSession;

importorg.apache.struts2.ServletActionContext;

importorg.apache.struts2.interceptor.ServletRequestAware;

importorg.apache.struts2.interceptor.ServletResponseAware;

importorg.apache.struts2.util.ServletContextAware;

importwww.csdn.struts_scope.domain.User;

importcom.opensymphony.xwork2.ActionContext;

importcom.opensymphony.xwork2.ActionSupport;

publicclassUsersActionextendsActionSupportimplementsServletRequestAware,

ServletResponseAware,ServletContextAware{

//调用servlet中的api

privateHttpServletRequestrequest;

privateHttpServletResponseresponse;

privateServletContextapplication;

privateUseruser;

publicUsergetUser(){

returnuser;

}

publicvoidsetUser(Useruser){

this.user=user;

}

//注入request

publicvoidsetServletRequest(HttpServletRequestrequest){

this.request=request;

}

//注入response

publicvoidsetServletResponse(HttpServletResponseresponse){

this.response=response;

}

//注入application

publicvoidsetServletContext(ServletContextapplication){

this.application=application;

}

publicStringlogin(){

request.setAttribute("user",user);

request.getSession().setAttribute("user",user);

application.setAttribute("user",user);

return"user_login";

}

如果能用ActionContext解决就不坚决不使用后边两种

就用方式一、ServeltActionContext

文件上传：

public String upload() {

// 首先确认你保存的路径 ServletContext application
// 创建文件
File file = new File(getPath());

if (!file.exists()) {
file.mkdirs();
}

try {

if (upload != null) {
for (int i = 0; i < upload.length; i++) {
File uploadFile = upload[i];

/*if(uploadFile==null){
continue;
}*/

// commons-io FileUtils工具 copyFile(要拷贝的文件,拷贝给谁的那个文件);
FileUtils.copyFile(uploadFile, new File(file, System
.currentTimeMillis()
+ "_" + uploadFileName[i]));
}

return "upload";
}

} catch (IOException e) {
e.printStackTrace();
}

return "fail";
}