js filereader

FileReader is similar to XMLHttpRequest, but it is used to read files from the file system, providing different ways to read file data:1, Readastext2, Readasdataurl3, Readasbinarystring4, ReadasarraybufferThe process of reading is asynchronous, some events can be monitored, progress,error,load, etc.The progress event does not trigger once in 50 milliseconds, and there is a lengthcomputable,loaded,total attribute that allows you to see how much data is

);//write the string into the file}Catch(IOException e) {System. out. println ("Error"+E); } }}Example: Copying a file to another fileImportJava.io.File;ImportJava.io.IOException;ImportJava.io.FileOutputStream;ImportJava.io.FileInputStream; Public class test{ Public Static void Main(String args[])throwsIOException {Try{File FromFile =NewFile ("A.txt"); File ToFile =NewFile ("B.txt"); FileInputStream FormS =NewFileInputStream (FromFile);//File input streamFileOutputStream ToS =NewFileOutpu

var input = document.getElementById ("J-btn-cont2");var Img_area = document.getElementById ("Ul-box");if (typeof (filereader) = = = ' undefined ') {DialogBox (' Your browser does not support FileReader properties, please change to a major browser ');Input.setattribute (' disabled ', ' disabled ');} else {$ (' #J-btn-cont2 '). On (' Change ', ' input[type=file] ', function () {var length = $ (' #ul-box li ')

Recently looking at a letter of Java small software source code, and then try to write their own, but in the reading of the file has been found "file not found" exception, check the various environment variables and directories, finally found the problem. The following are the specific error conditions:　　Import Java.io.FileReader; Public class test{ publicstaticvoid { new FileReader (" A.txt "); System.out.println (A.read ());}

FileReader and FileWriter Read and write Strings1 PackageObject.io;2 3 ImportJava.io.BufferedReader;4 ImportJava.io.BufferedWriter;5 ImportJava.io.FileReader;6 ImportJava.io.FileWriter;7 Importjava.io.IOException;8 9 Public classFileWrite {Ten One Public Static voidMain (string[] args)throwsIOException { A //TODO auto-generated Method Stub -FileReader reader=NewFileReader ("D:\\Program Files

Article reprinted from: http://blog.okbase.net/jquery2000/archive/1296.html;The Readasdataurl method of the FileReader object encodes the read file into the data URL. The data URL is a special technique that allows you to embed data (such as a sample) in a Web page without putting it in an external file. The advantage of using the data URL is that you do not need to send an additional HTTP request to the server to obtain additional data, and the disad

array B; When placed in an array cbuf, it does not start from the beginning of the array, but starts from the off position, returning the actual number of bytes read FileReader's parent inherits from reader and reads files using FileReaderCode 1-2Import Java.io.filereader;import Java.io.ioexception;public class Filereadertest {public static void main (string[] args {if (args = = NULL | | args.length = = 0) {throw new RuntimeException ("Please enter Path");}

exception is thrown and not processed. // Step 3: use the file class to find a file F = new file ("C:" + file. separator + "test.txt"); // declare the file object // Step 2: instantiate the parent class Object outputstream out = NULL through the subclass; // prepare an output object and use the object polymorphism, instantiate out = new fileoutputstream (f); // Step 4: Write a string. STR = "Hello world !!! "; // Only the byte array can be output, so the string is changed to byte array byte B [

Use html5 FileReader to retrieve images and upload them to the server asynchronously (without iframe ), Use html5 FileReader to retrieve images and upload them to the server asynchronously (without iframe) Principle: 1. Use FileReader to read the base64 encoding of the image 2. Use ajax to post the base64 encoded image to the server. 3. analyze the image type (j

(ioexception e ){// Todo auto-generated Catch BlockE. printstacktrace ();}}} } // Filereader Public class filereaderdemo {// Upstream stream (read operation)Public static void main (string [] ARGs ){ Filereader Fr = NULL;Bufferedreader BR = NULL;Try {Fr = new filereader ("abc.txt ");BR = new bufferedreader (FR );String STR = NULL; // stores the character data r

; Public class Testfileoutputstream { public static void Main (string[] args) throws Exception { //exception thrown, not processed //1th step: Use the file class to find a document File F = new file ("C:" + File.separator + "test.txt"); //Declare file object //2nd step: Instantiating a parent class object from a subclass OutputStream out = null; //Prepare an Output object, and instantiate it through the polymorphism of the object out = new FileOutputStream (f); //3r

Java io is really confusing, since there are FileWriter can write the character stream, why create DataOutputStream can also input character flow to the file. The following demo shows that files created by DataOutputStream can be read by FileReader. Package ZC; Import java.io.*; public class Test {public void stream () throws ioexception{ String s = "Hello world!"; DataOutputStream OS = new DataOutputStream (New FileOutputStream ("

Import java.io.*; public class Filereadersample {public static void main (String args[]) throws IOException {//Create an array that can hold 1024 characters Char Data[]=new char[1024]; Establish object Fr FileReader fr=new filereader ("C://java//donkey.txt"); Read the data into the character list, int num=fr.read (data); Converts a list of characters to a string Str=new string (data,0,num); Outp

Introduction: Title Packagecom.cc.test;ImportJava.io.FileReader;ImportJava.io.FileWriter; Public classTestchar { Public Static voidMain (string[] args) {FileReader Freader=NULL; FileWriter Fwriter=NULL; Try{Freader=NewFileReader ("E:/android/androidstudioprojects/text.txt"); Fwriter=NewFileWriter ("E:/android/androidstudioprojects/store.txt"); Char[] Cbuf =New Char[100]; Freader.read (Cbuf,0, cbuf.length); for(inti = 0;i ) {System.out.println (cbuf[

FileInputStream, FileReader, FileWriter, and File, inputstreamreader FileInputStream provides bytes for reading filesUsed to read original byte streams like data, such as: FileInputStream FD = new FileInputStream (new File ("D: \ 123.txt"); // create a FileInputStream object FileReader provides the ability to read characters from a file. It is inherited from the InputStreamReader class. This class re

This article describes how to use FileReader to encode a file into Base64 and upload it via AJAX, including the PHP code that the backend decodes and stores the file data, for more information about how to use AJAX, you cannot directly upload files. Generally, you can create a new iframe to complete the form submission process in it to achieve asynchronous file upload. This can achieve better browser compatibility, but the amount of code will be relat

1 we often need to upload avatar, click the Upload button need to preview, using the FileReader method does not need to interact with the background, the code is as follows://preview of local pictures before uploading//Image upload Previewfunctionpreviewimage (file) {if(File.files File.files[0]) { varimg = document.getElementById (' Imghead '); varReader =NewFileReader (); //load after reading file completeReader.onload =function(evt) {im

1. Get the File object firstvar file = $ ("input[type=file]") [0].files[0];2. Read the file using an object instance of FileReadervar reader = new FileReader ();Reader.onload = function (e) {var fileData = E.target.result;}Reader.readasdataurl (file);Can be used in the image upload file display and so on, in the file upload display can also use for attributes to better meet the customization of the upload interface, so that it better conform to the de

Baidu experience version: How to Use HTML5 FileReader to generate Data URLs Previous Article: Use Visual Studio 2010 to compile Data Url generation tool C # Today, we used HTML5 FileReader to implement the Data Url generation tool. Let's go to the Code: Finally:

Because the recent project to do a WebApp page, need to upload pictures, summed up a bit, the idea is as follows:First, listen for a Change event of input (type= ' file '), and then get the file;id= "Img-input" class= "Upload-input" type= " File " accept=" image/* "id=" Imgbox " multiple/>Second, turn file into Dataurl;/** *function filetodataurl (file, callback ) {new window. FileReader(); function (e) { callback (E.target.result); }; R