如何从无提交按钮调用Struts2操作

Question

I need to know how to call a Struts2 action from a button that does not submit the form. When I click on the button it should call a Struts2 action that will make a web service call to a SSRS server (SQL Server Reporting Services). The server sends the report to a stream that I put in the Response. It then displays a popup to download the PDF file. With JSF it's easy, the commandButton provides an "action" attribute. I'd like the equivalent of this:

<h:commandButton id="editButton" value="Edit" action="#{myBean.edit}" />

public class MyBean { public String edit() call web service, put the stream on the response return "OK"}}

How in Struts2? Ajaxa? JQuery? Dojo? I am new to Struts2 and Ajax, I do a lot of JSF.

thank you

Answer 1

Without submitting the form, you would need AJAX .

But since you simply need to download a PDF, then simply perform a GET call to an Action that returns a Stream Result (and won't change the current page).

Read more here

Specifying contentDisposition: attachment , you will ask the user where to download the file (or which application to use to open it), while contentDisposition: inline would open it inside the browser, changing the page (that is not what you want).

Then specify the action in url and use it anchor tag

<s:url action="downloadAction.action" var="url">
    <s:param name="param1">value1</s:param>
</s:url>
<s:a href="%{url}" >download</s:a>

and in Struts.xml

<result name="success" type="stream">
   <param name="contentType">application/pdf</param>
   <param name="contentDisposition">attachment;filename="yourPDF.pdf"</param>
</result>

In the Action you need to provide (through a getter) an InputStream called inputStream .

EDIT

If you want to do it from a button, like you asked in the comments:

<input  type = "button" 
       value = "download" 
     onclick = "javascript:location.href='downloadAction.action';"
/>

Answer 2

In dojo, you can create an iframe and make an ajax call to report service to get back a pdf file name, then download this pdf file in ifrmae:

    var reportCP = new dijit.layout.ContentPane({
        content: dojo.create("iframe")
    });   

    new dijit.Button({
        label: "Report",
        onClick: function(){

            dojo.request.post(yourServiceUrl, {
                data : yourData,
                handleAs: "json"
            }).then( 
                function(response){
                    reportCP.content.src=response.fileName;   
                },
                function(error){
                    alert(error);
                }
            );
        }
    });  

Or you can use window.open to download the pdf stream into a new window directly , like:

new dijit.Button({
    label: "Report",
    onClick: function(){
        window.open(yourReportServiceUrl,"","height=600, width=1000, scrollbars=1");
    }
});