Struts2 - 从 JSP 访问动作变量

Question

Struts2出了点小问题，不知道为什么不行……

我想通过 Action 类在两个 JSP 之间传递 2 个变量：

view1.jsp：

<s:form action="myAction">
   <input id="var1" name="var1" type="text" />
   <input id="var2" name="var2" type="text" />
   <button type="submit"> Ok </button>
</s:form>

-> var1 和 var2 是我要传递给 Action 类的变量

struts.xml：

<action name="myAction" class="MyAction" method="execute">
    <result name="success">view2.jsp</result>
</action>

Action.java：

public class MyAction extends DefaultActionSupport
{
    private String var1;
    private String var2;

public String execute() throws Exception
{
    // ... Some actions ...
    return SUCCESS;
}

// Getters & Setters for var1 and var2 (generated by Eclipse)
public String getVar1()
{
    return var1;
}

public void setVar1(String var1)
{
    this.var1 = var1;
}

public String getVar2()
{
    return var2;
}

public void setVar2(String var2)
{
    this.var2 = var2;
}

-> 这可以正常工作；如果我将“System.out.print”与 getter 放在一起，它会向我展示 var1 (content1) 和 var2 (content2) 的良好值

view2.jsp：

Values of var1 = <s:property value="var1" />
Values of var2 = <s:property value="var2" />

Textfield with var1 in default-value : <s:textfield value="%{var1}" />
Textfield with var2 in default-value : <s:textfield value="%{var2}" />

-> 这里有一个问题： 我无法获取 var1 和 var2 的内容！
-> <s:property value="var1" /> 和 <s:textfield value="%{var1} 返回“null”

我的错误在哪里？我不明白...我按照网上其他人所说的...

谢谢！

Answer 1

我终于找到了问题的答案！
要获得var1和var2的值，我必须使用以下几行：

view1.jsp：

<s:form action="myAction">
   <input id="var1" name="var1" type="text" />
   <input id="var2" name="var2" type="text" />
   <button type="submit"> Ok </button>
</s:form>

struts.xml：

<action name="myAction" class="MyAction" method="execute">
    <result name="success">view2.jsp</result>
</action>

Action.java：

public class MyAction extends DefaultActionSupport{
    private String var1;
    private String var2;

    public String execute() throws Exception{
        // ... Some actions ...

        ActionContext.getContext().getSession().put("var1", getVar1());
        ActionContext.getContext().getSession().put("var2", getVar2());

        return SUCCESS;
    }

    // Getters & Setters for var1 and var2 (generated by Eclipse)
    public String getVar1(){
        return var1;
    }

    public void setVar1(String var1){
        this.var1 = var1;
    }

    public String getVar2(){
        return var2;
    }

    public void setVar2(String var2){
        this.var2 = var2;
    }
}

view2.jsp：

Values of var1 = <s:property value="#session.var1" />
Values of var2 = <s:property value="#session.var2" />

//To transform var1 and var2 into JSP variables :

<s:set var="var1 " value="#session.var1 " />
<s:set var="var2 " value="#session.var2" />
<jsp:useBean id="var1 " type="java.lang.String" />
<jsp:useBean id="var2 " type="java.lang.String" />

<%
    String myString1 = var1;
    String myString2 = var2
%>