Struts: Implements argument Type Mismatch Error for image uploading.

Partial source code of upload. jsp:

<HTML: Form Action = "Upload. Do" method = "Post">

Select the photo to be uploaded:

<HTML: file property = "photofile"/>

<HTML: Submit value = "Upload"/>

</Html: Form>
Next, declare this attribute in actionform and set the getter and setter methods. The source code is as follows:

Public class uploadform extends actionform {

Protected formfile photofile;

Public formfile getphotofile (){

Return photofile;

}

Public void setphotofile (formfile photofile ){

This. photofile = photofile;

}

}
The photofile attribute of this form is not string or Boolean,
Org. Apache. Struts. Upload. formfile. Because the user uploads a binary file, and the HTTP protocol transmits data in the form of text, this requires
To convert. For example, a car needs to be sent from the ground a to the ground B, but there is only one cableway between the two places, and the car cannot be opened. So I want to find a way to remove the car in the ground, send parts to location B and then group again
Build a car. Formfile is used for disassembly and assembly, but it encapsulates the process of disassembly, transmission, and assembly. What we see is that a car enters from the ground.
Formfile. After a while, it will be opened from location B. All we have to decide is where to stop it. This is the activity of action.

Public class uploadaction extends action {
Public actionforward execute (actionmapping mapping, actionform form,
Httpservletrequest request, httpservletresponse response)
Throws exception {
Uploadform = (uploadform) form;
If (! Photofile. getfilename (). Equals ("")){
Try {

Inputstream stream = photofile. getinputstream ();
String filepath = request. getrealpath ("/");
Filepath = filepath + photofile. getfilename ();
Outputstream Bos = new fileoutputstream (filepath );
Int bytesread = 0;
Byte [] buffer = new byte [400000];
While (bytesread = stream. Read (buffer, 0, 400000 ))! =-1 ){
Bos. Write (buffer, 0, bytesread );
Bos. Flush ();
Bos. Close ();
Stream. Close ();
}
} Catch (exception e ){
System. Err. Print (E );
}
Photofile. Destroy ();
}

Return (mapping. findforward ("toindex "));
}
}
The following definitions in <action-mappings> In the struts-config.xml:
<Action Path = "/upload" type = "com. WebEx. TMIS. uploadaction" name = "uploadform" Scope = "request" input = "/wrong. jsp"/>
Run: The following exception is thrown:
Struts's argument Type Mismatch Error ..
Java. Lang. illegalargumentexception: cannot invoke com. WebEx. TMIS. uploadform. setphotofile-Argument Type Mismatch,
Debug
It turns out that the string is forcibly converted to formfile, so the argument type will be thrown.
Mismatch: In the form (HTML: form), enctype = "multipart/form-Data" means to set the form
Mime encoding. By default, the encoding format is application/X-WWW-form-urlencoded and cannot be used for file upload.
Multipart/form-data to increase the function of transferring file data, perform the following operations. enctype = "multipart/form-Data" is
Upload binary data;
The input values in form are passed in binary format. When enctype = "multipart/form-Data" is added to the HTML form
The Slice upload problem is solved.
The upload. JSP code is as follows:
<HTML: Form Action = "Upload. Do" enctype = "multipart/form-Data" method = "Post">

Select the photo to be uploaded:

<HTML: file property = "photofile"/>

<HTML: Submit value = "Upload"/>

</Html: Form>