Struts2_事物管理&文件上传

来源：互联网发布：国考行测技巧知乎编辑：程序博客网时间：2024/05/28 15:06

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

Admin entity; getEntity(){return entity;}; //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。

Struts2 ActionContext Map

public String scope() throws Exception{

ActionContext ctx = 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>

HttpServletRequest HttpSession ServletContext

Request session application

request.setAttribute(“name”，value);

${requestScope.name}

session.setAttribute(“name”,value);

${sessionScope.name}

application

ServletContext application = getServletContext();

application.setAttribute(“name”, value);

${application.name}

Struts2 servlet 松耦合

获取HttpServletRequest / HttpSession / ServletContext / HttpServletResponse对象

方式一：

ServletActionContext 调用Servlet API

//Struts2中提供 ServletActionContext

//request

HttpServletRequest request = ServletActionContext.getRequest();

request.setAttribute("user", user);

//session

HttpSession session = request.getSession();

session.setAttribute("user", user);

//application

ServletContext application = ServletActionContext.getServletContext();

application.setAttribute("user", user);

方式二：实现几个接口

package www.csdn.struts_scope.action;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import org.apache.struts2.interceptor.ServletRequestAware;

import org.apache.struts2.interceptor.ServletResponseAware;

import org.apache.struts2.util.ServletContextAware;

import www.csdn.struts_scope.domain.User;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UsersAction extends ActionSupport implements ServletRequestAware,

ServletResponseAware, ServletContextAware {

//调用servlet中的api

private HttpServletRequest request;

private HttpServletResponse response;

private ServletContext application;

private User user;

public User getUser() {

return user;

}

public void setUser(User user) {

this.user = user;

}

// 注入request

public void setServletRequest(HttpServletRequest request) {

this.request = request;

}

// 注入response

public void setServletResponse(HttpServletResponse response) {

this.response = response;

}

// 注入application

public void setServletContext(ServletContext application) {

this.application = application;

}

public String login(){

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";
}