SessionAware this.getSession().get("key") 总是给出 null struts2

Question

使用struts2，使用SessionAware将userObject保留在会话中，我发现在MainAction执行期间userObject在会话中正确设置，但是每次返回null时在另一个action（UploadAction）类中的不同流程中获取userObject。检查了很多东西但没有用。我是 struts 和 SessionAware 的新手，我在这里缺少什么？将所有相关代码放在这里。

public class WelcomeAction extends MainAction {

private UserObject userObject = new UserObject();
public String executeAction() {

userObject = //DB CALL;
this.getSession().put("user", userObject);
System.out.println("++"+this.getSession().get("user"));
    //giving me UserObject

}
}

public class MainAction extends ActionSupport implements SessionAware{
static Map<String,Object> session;

public MainAction() {       
        
    }



public Map<String,Object> getSession() {
        return session;
    }
    
    @Override
    public void setSession(Map<String,Object> session) {
        BaseAction.session = session;
    }


}


public class UploadAction extends MainAction implements ServletRequestAware{

public String executeAction() {

 UserObject uobj = (UserObject) this.getSession().get("user");// this line always give me null;
 
 //this uobj always null

}

}
struts.xml

    <interceptors>
            <interceptor name="sessionInterceptor"
                class="***.SessionInterceptor"></interceptor>
            <interceptor-stack name="loggingStack">
                <interceptor-ref name="sessionInterceptor" />
                <interceptor-ref name="defaultStack" />
            </interceptor-stack>
        </interceptors>
        <default-interceptor-ref name="loggingStack"></default-interceptor-ref>
        
        
        <action *******.WelcomeAction
            method="executeAction">
            <result name="success" type="redirectAction">*******</result>
        </action>
        
        
        <interceptors>
            <interceptor name="logInterceptor" class="*********LogInterceptor"></interceptor>
            <interceptor name="sessionInterceptor" class="*********.SessionInterceptor"></interceptor>
            <interceptor-stack name="loggingStack">
                <interceptor-ref name="sessionInterceptor" />
                <interceptor-ref name="logInterceptor" />       
                <interceptor-ref name="defaultStack" />             
            </interceptor-stack>
        </interceptors>     
        <default-interceptor-ref name="loggingStack"></default-interceptor-ref>
        
        
        <action name="upload"
            class="*******.UploadAction"
            method="executeAction">
            <interceptor-ref name="Upload">
            </interceptor-ref>                     
            <interceptor-ref name="defaultStack" />
            <result name="success" type="json">
                <param name="noCache">true</param>
                <param name="excludeNullProperties">false</param>
                <param name="contentType">text/html</param>
                <param name="includeProperties">sessionId.*,lstError.*,success.*,message.*</param>
            </result>   
            
            <result name="input" type="json">
                <param name="noCache">true</param>
                <param name="excludeNullProperties">false</param>
                <param name="contentType">text/html</param>
                <param name="includeProperties">success.*,message.*</param>
            
        </action> 

        
        web.xml 
        <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter
        </filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern></url-pattern>
    </filter-mapping>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>
    <servlet>
    <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet>
        <servlet-name>*******</servlet-name>
        <servlet-class>*******.Process******
        </servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>



SessionInterceptor::
    
    if ( !className.equalsIgnoreCase("WelcomeAction")
              && !className.equalsIgnoreCase("com.opensymphony.xwork2.ActionSupport")
              && ( session == null || session.isEmpty()) ) {
            return "session";
        } else {
            
            return actionInvocation.invoke();
        }

LogInterceptor

Map session = (Map)ActionContext.getContext().get("session");
        UserObject userObject = this.getSession().get("user"));
        if(userObject==null){
            
            return "session";
        }
        else{
            
        }
      
        String result = invocation.invoke();
    

Answer 1

您已使用不同的属性将会话对象注入到操作中。一个是

MainAction

的属性，另一个是

BaseAction

中的属性。当您调用

this.getSession()

时，它会从

session

返回一个

MainAction

，但是当注入会话对象时，属性为

BaseAction

。

您应该更改 setter 方法，以便在注入时将会话对象分配给

MainAction

@Override
    public void setSession(Map<String,Object> session) {
        this.session = session;
    }

不要使用操作的

static

属性。

---

还要正确实施

SessionAware

，您可以阅读this答案。

---

您还创建了两个

interceptor-stack

，名称为

loggingStack

，其中一个覆盖另一个。