How to read file(pdf or excel or outlook msg) from the path given in CSV and upload that file in Attachment object?

Question

I have requirement where I have to read a CSV file. Using CSV file I have to insert a records in Salesforce after that I have to upload attachment in newly inserted records.

CSV File will be having data to create a records as well as file name and file path(from local drive).

I have managed to insert a records and upload the given file under Notes & Attachment section of the newly created records. But when I download the uploaded file it will show the error message that file is damaged, which means Im not reading the file properly that resulting in inserting damaged file in Notes & Attachment.

below is my piece of code, can any one help me in reading file path from csv and uploading the corresponding file in Salesforce?

Apex Controller which is used to insert a Attachment file:

    for(Integer rowCount = 0 ; rowCount < listOfRows.size() ; rowCount++){    //It will iterate through each row of CSV File
    List<String> row = listOfRows[rowCount];
    for(Integer docCount = rowCount ; docCount<docsAttachmentList.size() ; docCount++){ //It will iterate through newly created records, in which I have to Insert a file
        Documents_Attachments__c doc = docsAttachmentList[docCount];
        if(row[0] == doc.COPF_ID__c){
            Attachment attacmentRec = new Attachment();
            attacmentRec.ParentId = doc.Id;
            attacmentRec.Name = row[2];   //row[2] is a file name
            attacmentRec.ContentType=contentType; 
            attacmentRec.Body = Blob.valueOf(row[3]); //row[3] is a file path
            attachmentToInsertList.add(attacmentRec);
            break;
        }
    }
}
insert attachmentToInsertList;

VF Page :

<apex:page controller="BulkUploadAttachmentsController"> 
<apex:form >
    <apex:sectionHeader title="Upload CSV File"/>
    <apex:pageBlock Title="CSV File Upload Section" >
        <apex:inputFile value="{!contentFile}" filename="{!nameFile}" contentType="{!contentType}" accept="csv"/>
        Select The Document type : <apex:selectList id="chooseColor" value="{!recordType}" size="1">
            <apex:selectOption itemValue="- None -" itemLabel="- None -"/>
            <apex:selectOption itemValue="Handover to PM" itemLabel="Handover to PM"/>
            <apex:selectOption itemValue="Handover to SS" itemLabel="Handover to SS"/>
        </apex:selectList> 
        <apex:pageBlockButtons location="Bottom" >
              <apex:commandButton action="{!BulkUploadAttachmentsController}" value="Upload File"  id="theButton" style="width:70px;" />
        </apex:pageBlockButtons>
    </apex:pageBlock>
</apex:form>

Answer 1

Apex Code can't read or write files directly to your computer. There's too many layers of security and other limitations that prevent this from happening. Literally, what you're doing in your code is saving the file's full path into the Attachment, which would only work for plain text files, but it still wouldn't be your intent, which is to read and upload the file.

If your really want to do this, you're going to need to move all of your code client-side, to JavaScript, and even then, you're going to have to help it along, as JavaScript can only select files specifically selected by a user in a secure dialog (e.g. a File Selection screen provided by the OS). Ideally you'd have no Apex Code at all, and just use Remote Objects to manipulate the data.