I want to open an Excel file through an Apex dialog box, then browse the information in my file line and display it with visualforce. I show you my code

public class ImportExcel {  
    public String fileName{get; set;}
    public Blob contentFile{get;set;}
    public String[] csvFileLines{get;set;}
    public List<String> acclist{get;set;}
    public String[] data{get;set;}
    public ImportExcel(){
        csvFileLines = new String[]{};
        acclist = New List<String>(); 
public void readFile(){
        }catch(Exception e){
        ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.FATAL,'Please upload a valid CSV document');
            return ; 
        for(Integer i=0;i<csvFileLines.size();i++){

Once I execute my code, it puts me this error:

13:52:13:012 VARIABLE_ASSIGNMENT [15]|e|"common.apex.runtime.impl.ExecutionException: BLOB is not a valid UTF-8 string"|0x4e4728

  • 1
    Please edit your existing question instead of opening a new one. Please make sure that all relevant information (code, objective, and error details) is in the body of your question. This time, I will close the previous question as a duplicate of this one, but please do familiarize yourself with How to Ask. – David Reed Apr 29 '19 at 12:33

This issue is with your file primarily and your code only secondarily. Apex (and Salesforce more broadly) only supports UTF-8 encoded text, or encodings like ASCII that are equivalent to UTF-8 for their codepoint ranges. What this error is telling you is that the file you've uploaded is not valid UTF-8 text, and therefore cannot be converted to an Apex String.

There are few routes around this in Apex. It's really a problem you should fix at the source (the file). The most likely case is that your file isn't really CSV but is a binary format. If it actually is CSV data (not just a file called .csv!), you should use a programmer's editor like Visual Studio Code to examine its contents and may need to re-save it using the UTF-8 encoding.

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