You have to wait for the image to load. Try handling the element inside .onload. I’ve also simplified the process of setting the source of the two elements to how you should be doing it (with jQuery). reader.onload = (function(theFile) { var image = new Image(); image.src = theFile.target.result; image.onload = function() { // access … Read more
Ended up not using FileReader at all, instead I looped through event.files and got each file by files[i] and sent an AJAX request by XHR with a FormData object (worked for me because I decided I don’t need to get the file data): var xhrPool = {}; var dt = e.dataTransfer; var files = (e.files … Read more
Sadly, the only answer I can come up with will hog some extra bandwidth. Firstly, use something like if (typeof FileReader !== “undefined” or Modernizr to follow your normal flow for the browsers that DO support FileReader. Otherwise, POST the file via AJAX to some server-side script that echoes back the contents. So for compliant … Read more
You are getting the characters  on the first line because this sequence is the UTF-8 byte order mark (BOM). If a text file begins with a BOM, it’s likely it was generated by a Windows program like Notepad. To solve your problem, we choose to read the file explicitly as UTF-8, instead of whatever … Read more
There is a super simple way to do this, along the lines of sowbug’s answer, but which doesn’t need any XHR or file reading. Step 1. Create resource/config.js like so: gOptions = { // This can have nested stuff, arrays, etc. color: ‘red’, size: ‘big’, enabled: true, count: 5 } Step 2. Include this file … Read more
Sample content of test.txt Hello Stack Over Flow com Code to read from this text file using lines() and forEach() methods. import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.stream.Stream; public class FileLambda { public static void main(String args[]) { Path path = Paths.of(“/root/test.txt”); try (Stream<String> lines = Files.lines(path)) { lines.forEach(s -> System.out.println(s)); } … Read more
Eventually I’ve created new line-by-line reader, which is totally different from previous one. Features are: Index-based access to File (sequential and random) Optimized for repeat random reading (milestones with byte offset saved for lines already navigated in past), so after you’ve read all file once, accessing line 43422145 will be almost as fast as accessing … Read more
I came up with a solution myself which works. function readmultifiles(files) { var reader = new FileReader(); function readFile(index) { if( index >= files.length ) return; var file = files[index]; reader.onload = function(e) { // get file content var bin = e.target.result; // do sth with bin readFile(index+1) } reader.readAsBinaryString(file); } readFile(0); }
You can use the standard FileReaderSync, which is a simpler, synchronous, blocking version of the FileReader API, similar to what you are already using: let reader = new FileReaderSync(); let result_base64 = reader.readAsDataURL(file); console.log(result_base64); // aGV5IHRoZXJl… Keep in mind though that this is only available in worker threads, for obvious reasons. If you need a … Read more
PrintWriter gives more methods (println), but the most important (and worrying) difference to be aware of is that it swallows exceptions. You can call checkError later on to see whether any errors have occurred, but typically you’d use PrintWriter for things like writing to the console – or in “quick ‘n dirty” apps where you … Read more