struts 取得request session application的四种方式

Action文件：
package struts2.login;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class LoginAction  extends ActionSupport{
    private ActionContext context;
    private Map request;
    private Map session;
    private Map application;
    
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        this.context = ActionContext.getContext();
        this.request = (Map)this.context.get("request");
        this.session = this.context.getSession();
        this.application = this.context.getApplication();
        return SUCCESS;
    }
}

2，servlet 不相关的 IoC 取得Request等对象的方式
这种方法，是实现特定的接口，由container来设定request等对象。

Action文件：
package struts2.login;

import java.util.Map;

import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;

import com.opensymphony.xwork2.ActionSupport;

public class Login2Action  extends ActionSupport
    implements RequestAware , SessionAware, ApplicationAware{
    private Map request;
    private Map session;
    private Map application;
    
    @Override
    public String execute() throws Exception {
        this.request.put("attribute", "request value servlet 不相关的 IoC ");
        this.session.put("attribute", "session value servlet 不相关的 IoC ");
        this.application.put("attribute", "application value servlet 不相关的 IoC ");
        return SUCCESS;
    }

    @Override
    public void setRequest(Map<String, Object> arg0) {
        // TODO Auto-generated method stub
        this.request = arg0;
    }

    @Override
    public void setSession(Map<String, Object> arg0) {
        // TODO Auto-generated method stub
        this.session = arg0;
    }

    @Override
    public void setApplication(Map<String, Object> arg0) {
        // TODO Auto-generated method stub
        this.application = arg0;
    }
}


3，servlet 相关的 非IoC 取得Request等对象的方式
这种方法可以获取servlet相关的request等对象，也就是说这种方式取出的request对象不单单是设定属性的作用，而是可以获取http相关的信息。
取出方法，请参看代码中的蓝字部分。

Action文件：
package struts2.login;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class Login3Action  extends ActionSupport{
    private HttpServletRequest request;
    private HttpSession session;
    private ServletContext application;
    
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        this.request = ServletActionContext.getRequest();
        this.session = this.request.getSession();
        this.application = ServletActionContext.getServletContext();
        this.request.setAttribute("attribute", "request value servlet 相关的 非IoC ");
        this.session.setAttribute("attribute", "session value servlet 相关的 非IoC ");
        this.application.setAttribute("attribute", "application value servlet 相关的 非IoC ");
        return SUCCESS;
    }
    
}


4，servlet 相关的 IoC 取得Request等对象的方式

这种方法也可以获取servlet相关的request等对象，也就是说这种方式取出的request对象不单单是设定属性的作用，而是可以获取http相关的信息。
但是取出方法是通过接口进行实现，也就是由struts2的container来设定。

Action文件：
package struts2.login;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.util.ServletContextAware;

import com.opensymphony.xwork2.ActionSupport;

public class Login4Action  extends ActionSupport
    implements ServletRequestAware , ServletContextAware{
    private HttpServletRequest request;
    private HttpSession session;
    private ServletContext application;
    
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        this.request.setAttribute("attribute", "request value servlet 相关的 IoC ");
        this.session = this.request.getSession();
        this.session.setAttribute("attribute", "session value servlet 相关的 IoC ");
        this.application.setAttribute("attribute", "application value servlet 相关的 IoC ");
        return SUCCESS;
    }

    @Override
    public void setServletRequest(HttpServletRequest arg0) {
        // TODO Auto-generated method stub
        this.request = arg0;
    }

    @Override
    public void setServletContext(ServletContext arg0) {
        // TODO Auto-generated method stub
        this.application = arg0;
    }
}