public class AskById extends BaseAction implements Action { private long id; public long getId() { return id; } public void setId(long id) { this.id = id; } public String execute() throws Exception{ return SUCCESS; }
} JSP中直接用${id}获取
request.getParameter("id"),还要进行强制类型转换 在action中定义一个 private int id;然后生成get,set方法 action会自动将页面传过来的id set到action中的id里面
首先建议你去查官方文档: 其实有很多方法获得request对象,这是其中一种 public class Test extends ActionSupport { private HttpServletRequest request; public void excute() { request = ServletActionContext.getRequest(); } }
public class AskById extends BaseAction implements Action { private long id; public long getId() {
return id;
} public void setId(long id) {
this.id = id;
} public String execute() throws Exception{
return SUCCESS;
}
}
JSP中直接用${id}获取
在action中定义一个 private int id;然后生成get,set方法
action会自动将页面传过来的id set到action中的id里面
不久可以了?
*方式一:
依赖于容器获取Map类型的request,session,application
<>在action中定义:private Map request;
private Map session;
private Map application;
<>可以在构造器里面或者其他地方用一下方法获取这三个元素:
request = (Map)ActionContext.getContext().get("request");
session = ActionContext.getContext().getSession();
application = ActionContext.getContext().getApplication();
[Debug]里面的Action Context中可以查看到
<>我们获取的虽然都是Map,但是我们通过put方法将键值对存入Map之后,struts2
会帮助我们和HttpRequest对象建立起联系,将值存入HttpRequest对象
<>前台页面访问形式:<s:property value="#request.key"/>
如果用<s:property value="#attr.key"/>可访问这三个对象中的值 *方式二:
IoC获取Map类型的request,session,application
IoC-Inverse of Control控制反转
DI-Dependency Injection依赖注入
<>action类中实现三个接口:RequestAware,SessionAware,ApplicationAware
让action知道这三个对象的存在,并且要实现三个方法;
2>在action中定义三个Map,加上范型:
private Map(String,Object) request;
private Map session;
private Map application;
*方式三:
依赖于容器获取HttpServletRequest,HttpSession,ServletContext对象
<>在Action类中声明三个属性:
private HttpServletRequest request;
private HttpSession session;
private ServletContext application;
<>用如下方法可以获得这三个对象:
request = ServletActionContext.getRequest();
session = request.getSession();
application = session.getServletContext();
*方式四:
IoC获取HttpServletRequest,HttpSession,ServletContext对象
1>Action类实现ServletRequestAware接口,实现接口中的方法
2>在Action中定义:
private HttpServletRequest request;
private HttpSession session;
private ServletContext application;
其实有很多方法获得request对象,这是其中一种
public class Test extends ActionSupport { private HttpServletRequest request; public void excute() {
request = ServletActionContext.getRequest();
}
}
import javax.servlet.http.HttpServletResponse; //在要用request的地方:
HttpServletRequest request = ServletActionContext.getRequest();
//HttpServletResponse response = ServletActionContext.getResponse();
//HttpSession session = request.getSession(); //在这里 和servlet里面一样去request.getParameter("id"),
import com.opensymphony.xwork2.Action;public class LoginAction implements Action
{
private User user; @Override
public String execute() throws Exception
{
if("zhangsan".equals(user.getUsername()) && "1234".equals(user.getPassword()))
return SUCCESS;
else
return ERROR;
} public User getUser()
{
return user;
} public void setUser(User user)
{
this.user = user;
}
}