在 Struts2 中执行另一个操作后，值堆栈的值发生变化

Question

I have like following jsp .I send some data via form and execute Action ,我喜欢关注jsp 。我通过表单发送一些数据并执行Action ，

case.jsp

before action:${CasePostFormBean.subject}
<s:action var="ServletHelperAction" name="login-user-to-bean" namespace="/servlet-helper"></s:action>
after action:${CasePostFormBean.subject}

<input name="CasePostFormBean.subject" value="${CasePostFormBean.getSubject()}" form="formCasePost">

<form method="post" id="formCasePost" submit="case-create"></form>

servlethelper.jsp

<html></html>

CasePostAction.java

public class CasePostAction extends ActionSupport implements SessionAware {

    @Getter @Setter
    private CasePostFormBean casePostFormBean = new CasePostFormBean();

    @Action(value = "case-create", results = {
        @Result(location = "case.jsp")
    })
    public String register() {
        this.casePostFormBean.setSubject("success to send form");
        return SUCCESS;
    }
}
}

public class ServletHelperAction extends ActionSupport implements SessionAware  {

    // Beans
    @Getter @Setter
    private UserParamsBean userParamsBean = new UserParamsBean();

    @Action(value = "login-user-to-bean", results = {
        @Result(location = "servlethelper.jsp")
    })
    public String loginUserToBean() {
        final MstUserModel mstUserModel = new MstUserModel(this.dbManager.getSqlSession());

        if (this.session.get("userParamsBean.userCode") != null) {
            this.userParamsBean.setUserCode(this.session.get("userParamsBean.userCode").toString());

            Map<String, Object> loginUser = mstUserModel.selectUserOne(1, this.userParamsBean.getUserCode()).get(0);
            this.userParamsBean.setUserName(loginUser.get("name").toString());
        }
        return SUCCESS;
    }
}

After input input value and after button submitted, like following was shown.输入input value并提交按钮后，如下所示。

before action: success to send form
after action: input value

Out put is like follows, When I execute another action via <s:action> the value stack seems to be changed.输出如下，当我通过<s:action>执行另一个操作时，值堆栈似乎发生了变化。 Seems that after <s:action> these sent data was recaptured by value stack.似乎在<s:action>之后，这些发送的数据被值堆栈重新捕获。

My desired result is like我想要的结果就像

before action: success to send form
after action: success to send form

What is the root cause of this?根本原因是什么？

Answer 1

If you set some bean to the action object, then it belongs to it until you reference it someare else, ie a session map. Since you have to implement a SessionAware interface on CasePostAction .如果您将某个 bean 设置为操作 object，那么它属于它，直到您在其他地方引用它，即 session map。因为您必须在CasePostAction上实现SessionAware接口。 Then you put CasePostFormBean into the session map. In this way the scope of the object will be a session scope until you remove it from the session or invalidate a session map.然后，您将CasePostFormBean放入session882477763218788。以这种方式，8828299540288的scope将是session88888888888888888888888888888888888888.

In the JSP you use EL expression to search for the CasePostFormBean .在 JSP 中，您使用 EL 表达式来搜索CasePostFormBean 。 Currently you keep it in the action bean and a scope belongs to the action scope.目前，您将其保存在操作 bean 中，而 scope 属于action scope。

The action scope is similar to the request if you don't instantiate other actions in the request like <s:action> .如果您不在请求中实例化其他操作，例如<s:action> ，则action scope 类似于request 。 Each action has its own action scope and therefore a ValueStack .每个动作都有自己的action scope ，因此有一个ValueStack 。

Change the code更改代码

public class CasePostAction extends ActionSupport implements SessionAware {

    @Getter @Setter
    private CasePostFormBean casePostFormBean = new CasePostFormBean();

    @Getter @Setter
    private Map<String, Object> session;

    @Action(value = "case-create", results = {
        @Result(location = "case.jsp")
    })
    public String register() {
        
this.casePostFormBean.setSubject("success to send form");
        session.put("casePostFormBean", casePostFormBean);
        return SUCCESS;
    }
}
}

When a result is executed you should reference this object directly from the session.执行结果时，您应该直接从 session 引用此 object。

before action:<s:property value="%{#session.casePostFormBean.subject}"/>
<s:action var="ServletHelperAction" name="login-user-to-bean" namespace="/servlet-helper"></s:action>
after action:<s:property value="%{#session.casePostFormBean.subject}"/>

在 Struts2 中执行另一个操作后，值堆栈的值发生变化

问题描述

1 个解决方案

解决方案1
0 2022-12-26 11:29:00

在 Struts2 中执行另一个操作后，值堆栈的值发生变化

问题描述

1 个解决方案

解决方案1 0 2022-12-26 11:29:00

解决方案1
0 2022-12-26 11:29:00