base64

JAVA base64与图片的转换

由 孤街浪徒 提交于 2020-01-18 01:38:16
想看原文请移步下面 转载: https://www.jianshu.com/p/f9e04600bbf3 Base64生成图片的方法 /** * base64生成图片方法 * @param imgData base64字符串 * @param imgFilePath 图片的生成路径 * @return 是否生成成功 * @throws IOException */ public static String GenerateImage ( String imgData , String imgFilePath ) throws IOException { // 对字节数组字符串进行Base64解码并生成图片 if ( imgData == null ) // 图像数据为空 return "" ; //随机生成一个UUID并去除他的 "-" String s = UUID . randomUUID ( ) . toString ( ) . replaceAll ( "-" , "" ) ; imgFilePath += s + ".jpg" ; BASE64Decoder decoder = new BASE64Decoder ( ) ; OutputStream out = null ; try { out = new FileOutputStream ( imgFilePath )

根据百度网盘的上传原理，自己写大文件上传

由 ￡可爱￡侵袭症＋ 提交于 2020-01-17 19:44:56
在之前大文件的上传我都是通过FilderReader获取文件的base64然后转为Blob在一段一段截取上传，但是这个方法有个弊端就是很大的文件的时候获取文件的base64会使整个浏览器崩溃卡死，后面我去看了一下百度网盘的上传原理 我们可以看到百度是通过类似表单提交的方式上传文件的，这样子似乎不需要把文件转化为base64减少了浏览器的开销。那个让我们来动手做一个大文件上传吧 这里用input标签来获取需要上传的文件 获取到file对象以后我们就可以得到 这样一个对象里面就是文件的大小名字等信息 接下来我们可以通过size判断文件的大小，对大文件进行切割上传处理 大文件上传的话我们需要告诉后端切割的总公块数和当前是那一块这样子后端可以对数据进行处理 这里我们通过step控制切割的大小，star和end表示该次上传的文件开始个结束的数据位置，totalindex是总共切割的个数，index是当前上传的个数 以上就是我的大文件上传的方法~~~~ 快过年了，在这里提前祝大家新年快乐！！！！！！！！！！！！ 来源： https://www.cnblogs.com/july-lin/p/12206973.html

base64 string to byte to image

由 允我心安 提交于 2020-01-17 15:48:27
问题 I have a base64 string which was generated from an image using another application. Now on my application I want to convert the base64 string to byte and display it on a PictureBox. I already found a sample application which takes a byte input and sets a PictureBox image. Unfortunately the sample application gets the byte array from an image and just translates it back. Here's the function it uses. Public Function PictureFromByteStream(b() As Byte) As IPicture Dim LowerBound As Long Dim

Base64与File之间的相互转化

由 对着背影说爱祢 提交于 2020-01-17 08:43:00
/** * * @param path * @return String * @description 将文件转base64字符串 * @date 2018年3月20日 * @author changyl * File转成编码成BASE64 */ public static String fileToBase64 ( String path ) { String base64 = null ; InputStream in = null ; try { File file = new File ( path ) ; in = new FileInputStream ( file ) ; byte [ ] bytes = new byte [ ( int ) file . length ( ) ] ; in . read ( bytes ) ; base64 = Base64 . getEncoder ( ) . encodeToString ( bytes ) ; } catch ( Exception e ) { e . printStackTrace ( ) ; } finally { if ( in != null ) { try { in . close ( ) ; } catch ( IOException e ) { e . printStackTrace ( ) ;

Comparing base64 image strings in Golang

由 ≡放荡痞女 提交于 2020-01-17 03:38:28
问题 I have a service that compares two base64 encoded image strings My initial attempt revealed that there is differences in metadata while the actual image (JPG) in this case is identical (size,resolution,dimensions,etc). Is there a way to strip away much of the dynamic metadata so that I can just compare the visual aspect of the image? Currently, I am using the following... package converter import ( "bufio" "encoding/base64" "log" "os" ) func Base64(path string) (string, error) { imgFile, err

NodeJS base64 image encoding not quite working

由 巧了我就是萌 提交于 2020-01-17 01:48:05
问题 I am using API to get user's profile photo from O365 cloud. Based on the doc it says response contains *The binary data of the requested photo. * I would like to use this image to be displayed by Data URI format. Ex:- "data:image/png;base64,iVBORw0KGgoAAA ANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4 //8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU 5ErkJggg==" where everything after data:image/png;base64,.... is image data in Base64. I unable to get Base64 encoding working for the image data I

Python / Django fails at decoding file encoded as base64 by javascript

由 早过忘川 提交于 2020-01-16 18:17:28
问题 I'm using this, in react, to base64 encode an image file: fileToBase64 = (filename, filepath) => { return new Promise(resolve => { var file = new File([filename], filepath); var reader = new FileReader(); reader.onload = function(event) { resolve(event.target.result); }; reader.readAsDataURL(file); }); }; Which gets called by this: handleChangeFile = event => { const { name, files } = event.target; if (files.length) { const file = files[0]; let fields = this.state.fields; this.fileToBase64

toDataURL's output is base64, how to reduce the uploading time and bandwidth of a factor 1/3?

由 我怕爱的太早我们不能终老 提交于 2020-01-16 18:05:06
问题 The goal of the following code is to compress the input file (2 MB JPG file => 500 KB file) and then upload it to server when submitting the <form> . When importing an image from a JPG file into a canvas, and exporting it with toDataURL with: function doit() { var file = document.getElementById('file').files[0], canvas = document.getElementById('canvas'), hidden = document.getElementById('hidden'), ctx = canvas.getContext("2d"), img = document.createElement("img"), reader = new FileReader();

toDataURL's output is base64, how to reduce the uploading time and bandwidth of a factor 1/3?

由 孤街醉人 提交于 2020-01-16 18:04:39
问题 The goal of the following code is to compress the input file (2 MB JPG file => 500 KB file) and then upload it to server when submitting the <form> . When importing an image from a JPG file into a canvas, and exporting it with toDataURL with: function doit() { var file = document.getElementById('file').files[0], canvas = document.getElementById('canvas'), hidden = document.getElementById('hidden'), ctx = canvas.getContext("2d"), img = document.createElement("img"), reader = new FileReader();

java 和Python ASE加密解密

由 耗尽温柔 提交于 2020-01-16 14:41:30
java实现 @Slf4j public class AESUtil { private static String ivParameter = "t234DsfDgdKKAVDd"; private static String salt = "Loefcodr046DKRVd"; /** * 解密. */ public String decrypt(String sSrc) { try { byte[] raw = salt.getBytes("ASCII"); SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes()); cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv); byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);//先用base64解密 byte[] original = cipher.doFinal(encrypted1); String
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