如何检测在单个 Action 类中的多个提交按钮场景中单击的提交按钮? [英] How to detect submit button clicked in multiple submit buttons scenario in single Action class?

问题描述

我在jsp中有一个表单.有两个提交按钮:搜索"和添加新"按钮.

I have a form in a jsp. There are two submit buttons: "Search" and "Add New" button.

<s:form name="searchForm" action="employeeAction" method="post">
    <s:textfield name="id" label="Employee ID"/>
    <s:textfield name="name" label="Employee Name"/>

    <s:submit value="Search"/>
    <s:submit value="Add New"/>
</s:form>

在struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />

    <package name="default" namespace="/" extends="struts-default">

        <default-action-ref name="index" />

        <global-results>
            <result name="error">/error.jsp</result>
        </global-results>

        <global-exception-mappings>
            <exception-mapping exception="java.lang.Exception" result="error"/>
        </global-exception-mappings>

    </package>

    <package name="example" namespace="/example" extends="default">

        <action name="employeeAction" class="example.EmployeeAction">
           <result name="search">/example/search.jsp</result>
           <result name="add" type="redirect">/example/add.jsp</result>
        </action>

    </package>
</struts>

在Struts Action类中，我们知道处理http请求的方法只有一种，就是execute()方法.

In Struts Action class, we know that there is only one method that processing http request, that is execute() method.

在我预期的情况下，当我点击搜索按钮时，它会执行搜索数据并将数据呈现到/example/search.jsp，当我点击添加新按钮，它将执行重定向页面到/example/add.jsp.但是，两个按钮在被点击时都会进入 execute() 方法.所以我需要知道如何检测在 execute() 方法中点击了哪个按钮.

In my expected case, when I clicked Search button, it will perform searching data and render data to /example/search.jsp, when I clicked Add New button, it will perform redirecting page to /example/add.jsp. However, both buttons when clicked will go into execute() method. So I need to know how to detect which button clicked in the execute() method.

场景是这样的

public class EmployeeAction extends ActionSupport {

    public String execute() throws Exception {

        //PSEUDOCODE
        //IF (submitButton is searchButton) 
        //    return doSearch();
        //ELSE IF (submitButton is addNewButton) 
        //    return doAddNew();

        return SUCCESS;
    }

    public String doSearch() throws Exception {
        //perform search logic here
        return "search";
    }

    public String doAddNew() throws Exception {
        return "add";
    }
}

推荐答案

您可以在 struts.xml 文件中定义两个动作，并使用 标签的 action 属性来提交不同的动作 http://struts.apache.org/docs/submit.html.

You can define two actions in struts.xml file and use action attribute of <s:submit> tag in order to submit to different actions http://struts.apache.org/docs/submit.html.

在 JSP 中:

<s:submit value="Search" action="searchEmployeeAction"/>
<s:submit value="Add New" action="addEmployeeAction"/>

在 struts.xml 中:

In struts.xml:

<action name="addEmployeeAction" method="add" class="example.EmployeeAction">
    <result>/example/add.jsp</result>
</action>

<action name="searchEmployeeAction" method="search" class="example.EmployeeAction">
    <result>/example/search.jsp</result>
</action>

并在您的操作中创建两个 public String 方法 add 和 search.

And in your action create two public String methods add and search.

阅读多个提交按钮http://struts.apache.org/docs/multiple-submit-buttons.html.

更新

从 Struts2 版本 2.3.15.3 开始，您需要将 struts.mapper.action.prefix.enabled 常量设置为 true 以启用对 action: 前缀的支持.

Starting from Struts2 version 2.3.15.3 you need to set struts.mapper.action.prefix.enabled constant to true in order to enable support for action: prefix.

把它放在你的 struts.xml 文件中:

Put that in your struts.xml file:

<constant name="struts.mapper.action.prefix.enabled" value="true" />

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