Action 访问 Servlet API 的方式
这里只针对 Servlet 中常用的，如 HttpServletRequest、HttpServletResponse 和 HttpSession 来展开。
一般来说，在 Struts2 中访问 Servlet API 的方式有2种：
(1) 直接访问 Servlet API。这将会使得你的 Action 类与 Servlet API 耦合在一起。
(2) 通过 Struts2 API 来访问 Servlet API，这样 Action 类就不会再跟 Servlet API 耦合。
通过 ServletActionContext 来访问 Servlet API ( 耦合 )
package fan.tutorial.action;
import com.opensymphony.xwork2.Action;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
public class ServletApiAction implements Action {
private HttpSession session;
private HttpServletRequest request;
private HttpServletResponse response;
public String execute() throws Exception {
request = ServletActionContext.getRequest();
session = request.getSession();
response = ServletActionContext.getResponse();
request.setAttribute("requestScopeParam", "fan");
session.setAttribute("sessionScopeParam", "tutorial");
response.setHeader("expires", "-1");
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
return SUCCESS;
}
}
通过 ServletRequestAware、ServletResponseAware 接口来访问 Servlet API ( 耦合 )
package fan.tutorial.action;
import javax.servlet.http.HttpSession;
import com.opensymphony.xwork2.Action;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
public class IServletApiAction implements Action, ServletRequestAware, ServletResponseAware {
private HttpSession session;
private HttpServletRequest request;
private HttpServletResponse response;
public String execute() throws Exception {
request.setAttribute("requestScopeParam", "fan");
session.setAttribute("sessionScopeParam", "tutorial");
response.setHeader("expires", "-1");
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
return SUCCESS;
}
public void setServletRequest(HttpServletRequest request) {
this.request = request;
this.session = request.getSession();
}
public void setServletResponse(HttpServletResponse response) {
this.response = response;
}
}
通过 ActionContext 来访问 Servlet API ( 解耦 )
package fan.tutorial.action;
import java.util.Map;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;
public class StrutsServletApiAction implements Action {
private Map<String, Object> session;
private Map<String, Object> request;
private ActionContext context = ActionContext.getContext();
public String execute() throws Exception {
session = context.getSession();
request = (Map<String, Object>)context.get("request");
request.put("requestScopeParam", "fan");
session.put("sessionScopeParam", "tutorial");
return SUCCESS;
}
}
通过 RequestAware、SessionAware 接口来访问 Servlet API ( 解耦 )
package fan.tutorial.action;
import java.util.Map;
import com.opensymphony.xwork2.Action;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;
public class IStrutsServletApiAction implements Action, RequestAware, SessionAware {
private Map<String, Object> session;
private Map<String, Object> request;
public String execute() throws Exception {
request.put("requestScopeParam", "fan");
session.put("sessionScopeParam", "tutorial");
return SUCCESS;
}
public void setRequest(Map<String, Object> request) {
this.request = request;
}
public void setSession(Map<String, Object> session) {
this.session = session;
}
}
Struts2 对 HttpServletRequest 和 HttpSession 做了一层封装，使用 Map<String, Object> 来替换掉这2种对象，这样可避免 Action 类与 Servlet API 耦合在一起。
struts-servlet.zip
posted on 2014-03-17 19:58
fancydeepin 阅读(2043)
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