Some error-prone problems when using struts to process web programs

1. Question about JSP page forms and <div> </div>.

Previously, there was a page in the project, because there were a lot of things on the page, so multiple <div> </div> were used,
Then, when I submit a form, the script called cannot find the form I submitted.
The reason is that <div> </div> indicates a region. When a form spans one or more Divs, a problem occurs,
The from form must be in the div.

Previously, there was a page in the project, because there were a lot of things on the page, so multiple <div> </div> were used,
Then, when I submit a form, the script called cannot find the form I submitted.
The reason is that <div> </div> indicates a region. When a form spans one or more Divs, a problem occurs,
The from form must be in the div.

For example:
 
<HTML: Form Action = "/infomanagement" target = "hiddenframe" method = "Post" enctype = "multipart/form-Data" style = "margin: 0px;">
<Div id = "employeeinfo" style = "display: none">
<Table width = "100%" border = "0" cellspacing = "0" cellpadding = "0" style = "padding-left: 8px; padding-Right: 8px">
<Tr>
<TD nowrap> ...... </TD>
</Tr>
</Table>
</Div>

//------------------------------

<Div id = "centercontent" style = "display: none">
<Table width = "100%" border = "0" cellpadding = "0" cellspacing = "0" style = "padding-left: 8px; padding-Right: 8px">
<Tr>
<TD> ...... </TD>
</Tr>
</Table>
</Div>
</Html: Form>

In this case, the form spans multiple Divs. When submitting the form, the page reports an error: the form is not defined.

Solution 1: combine two divs into one. If you need to display the page effect, you can control the style of the two tables and place the form inside the div.
Solution 2: Check the submitted content. If you only need the content in one Div, you can put the form in only one Div,
For example:

<Div id = "employeeinfo" style = "display: none">
<Table width = "100%" border = "0" cellspacing = "0" cellpadding = "0" style = "padding-left: 8px; padding-Right: 8px">
<Tr>
<TD nowrap> ...... </TD>
</Tr>
</Table>
</Div>

//------------------------------

<Div id = "centercontent" style = "display: none">
<HTML: Form Action = "/infomanagement" target = "hiddenframe" method = "Post" enctype = "multipart/form-Data" style = "margin: 0px;">
<Table width = "100%" border = "0" cellpadding = "0" cellspacing = "0" style = "padding-left: 8px; padding-Right: 8px">
<Tr>
<TD> ...... </TD>
</Tr>
</Table>
</Html: Form>
</Div>

2. About how to use struts to process the form with uploaded files

When processing a form with Struts, you must first add enctype = "multipart/form-Data" to the form, for example
<HTML: Form Action = "/infomanagement" target = "hiddenframe" method = "Post" enctype = "multipart/form-Data" style = "margin: 0px;">
.......
</Html: Form>
In addition, define the corresponding formfile object and (get/set method) in the corresponding * form. java)

Note the following:
<Table>
<Tr>
<TD>
<Logic: notempty name = "infoform" property = "values (employee). Values (photo)">
<Bean: Define id = "photo" name = "infoform" property = "values (employee). Values (photo)" type = "Java. Lang. String"/>
<Bean: Define id = "photonum" name = "infoform" property = "values (employee). Values (photonumber)" type = "Java. Lang. String"/>
<% --
Document. Write ("photo =" + <% = photo %> );
Document. Write ("src =" + <% = request. getcontextpath () + photo %> );
<HTML: hidden name = "infoform" property = "photonumber" value = "<% = photo %>"/>
-- %>
<HTML: hidden name = "infoform" property = "values (photolastname)" value = "<% = photonum %>"/>
<Tr>
<TD Height = "20" nowrap> <Div align = "Left"> <strong> <Bean: Message key = "STF. infocenter. photo "bundle =" staffing "/>:</strong> </div> </TD>
</Tr>
<Tr>
<TD nowrap>
<Div id = "img0" style = "display: Block"> "width =" 250 "/> </div>
<Div id = "img1" style = "display: none"> </div>
</TD>
</Tr>
<Tr>
<TD align = "center">
<Button class = "button" onclick = "fntoggle1 (this, 'img0 ', 'img1',' <Bean: Message key =" STF. basicinfo. normalsize "bundle =" staffing "/> ',' <Bean: Message key =" STF. basicinfo. scalesize "bundle =" staffing "/> ');"> <Bean: Message key = "STF. basicinfo. scalesize "bundle =" staffing "/> </button>
</TD>
</Tr>
</Logic: notempty>
</TD>
</Tr>
</Table>

In the above Code, pay attention to this line
[1]: <HTML: hidden name = "infoform" property = "values (photolastname)" value = "<% = photonum %>"/>

You can also write it like this.
[2]: <HTML: hidden name = "infoform" property = "photolastname" value = "<% = photonum %>"/>

[Note: The values here is only a map defined in form to facilitate the value transfer in pages and actions]

However, the Code contains the string file and enctype = "multipart/form-Data", which makes struts significantly different when assembling the form.
For example, my form name is informationform infoform = (informationform) form. I will directly describe it using infoform later.
If method [1] is used for form submission, the submitted information is stored in infoform [(hashmapz) Values,

Parameter Extraction Method:
String STR = (string) infoform. getvalue ("photolastname ");
If (STR! = NULL & Str. Trim (). Length ()> 0 ){
Infoform. setvalue ("photo", STR );
}

Method [2] is used for form submission. After submission, the information is stored in
Infoform [(commonsmultipartrequesthandle) multipartrequesthandle [elementsall and elementstext.

All colleagues who are recommended to work as Struts web projects should try their best to select the first method. Also, do not add enctype = "multipart/form-Data" to the pages that do not need to upload attachments ",
To avoid other problems, debugging takes time.