使用java将图像转换为base64

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时间:2020-08-11 05:53:09  来源:igfitidea点击:

convert image to base64 with java

javaimagejspservletsbase64

提问by NoSixties

I need to convert a image object to a base64 object so I can load it into the tag on my client side.

我需要将图像对象转换为 base64 对象,以便将其加载到客户端的标签中。

However I can't seem to figure out how to pull this off. Is there anyone who has a piece of code for this that I could use easily?

但是,我似乎无法弄清楚如何实现这一点。有没有人有一段我可以轻松使用的代码?

This is what I use to turn the external image link into a image object

这是我用来把外部图片链接变成图片对象的

Image image = null;
URL url = new URL(request.getParameter("hdn_path"));
image = ImageIO.read(url);

not sure if I'm going about this the correct way.

不确定我是否以正确的方式解决这个问题。

采纳答案by Jean Logeart

Using Apache IOUtilsand Base64:

使用 ApacheIOUtilsBase64

byte[] imageBytes = IOUtils.toByteArray(new URL("...")));
String base64 = Base64.getEncoder().encodeToString(imageBytes);

回答by Adam

  • write using ImageIO.write().
  • ByteArrayOutputStream wraps the byte array so it can be used as an output stream.
  • convert the byte array to a a base64 string using DatatypeConverter, in core Java since 6, no extra libraries required
  • 使用 ImageIO.write() 写入。
  • ByteArrayOutputStream 包装字节数组,因此它可以用作输出流。
  • 使用 DatatypeConverter 将字节数组转换为 base64 字符串,从 6 开始在核心 Java 中,不需要额外的库

Example

例子

ByteArrayOutputStream output = new ByteArrayOutputStream();
ImageIO.write(image, "png", output);
DatatypeConverter.printBase64Binary(output.toByteArray());

回答by Raju

Accepted answerreads the file from URL, if any one looking for image to Base64 encoding by reading the image from file system, below snippet can be used.

接受的答案从 URL 读取文件,如果有人通过从文件系统读取图像来寻找 Base64 编码的图像,则可以使用以下代码段。

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Base64;
import org.apache.commons.io.IOUtils;

public String img2Text(){
    String base64="";
    try{
        InputStream iSteamReader = new FileInputStream("featured-700x467.png");
        byte[] imageBytes = IOUtils.toByteArray(iSteamReader);
        base64 = Base64.getEncoder().encodeToString(imageBytes);
        System.out.println(base64);
    }catch(Exception e){
        e.printStackTrace();
    }
    return "data:image/png;base64,"+base64;
}

Returned base64 text can be used in HTML pages like below example

返回的 base64 文本可用于 HTML 页面,如下例所示

<!DOCTYPE html>
<html>
<body>

<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACoAAAAqCAYAAADFw8lbAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAfDSURBVFhHrZihb2NHEMatKpUCAgIMQgMOFIZUKg3oH9F/oaCwqo4GFAREVRUdMDWwTgcCopOB6VNlEFXRySDgUUtxKoMAA1+0N7/Z/db7Xl5in64rjd++3X0z3347M7vr3tFxL7wmlLIewjI9N+1lf3c9ftNu/xrZCahKu+8xYV6tHvNY6i6P89zfVehr63tNtgKVqOh9sVjn9rt6Fh7uFw6O+v39nb8j9Tyi5anx0gHTqm+TnYCqLB8jGKSezxzUp093Lv/8Ow3T6dilqqb5/XY2DpPpxL+f3S1cx+O6zquwq+y89CjGAGwBAnAA+vhxGkajSRi8G4fhYBAGw2G4fHdp76MwHI28j/GT6kO4ub0Nd3frMK+Xzjb6umx2yVagAFyuo+Kb6W1m0IEMqnB+NgwHe8eh1+uFvb4ptGdbzs/OHfzV1VWYjG+d2ewuyae7bJfyIlApYNZSWk1m4f37q/D27a/hKIE6trHz+WH4HH4Mi6WtwOfvQ1j3wyrs+fPh4SSPPdzrhYvz38L15MwZhl30Il0YStkKtJ5XziRLPLgYukGYq5enxvQbC9++A3KAyGMCW9T/e/ouPD29CfPlz4nlvjM8uqpCXdc7gXUnpFI+xSQg3b8mdbj86w83cmQiYBhvgxOTq5U9aSvrJnwDs+hi4tX1PMxmU7eFi6mUIJGIzIpAUvhAEY1fESgoZnkdzKrJ4Gp5EMGnCTiwBFAg1eb1EF0CnX+e/e5uUNcGOGUFsVumL196ip6wyUAi06N5cOYKUZ7BYWxh4/WeADizCWDuM3kGNgPec/9ltQhMwJJVKM+AeqsVADIbOvFJAoelIaKlvAGgNCggJfjkDnKFsg0hAGmHWVzhengTAywFbjt19QCnFxK5+8ts4dENk8emhGBwAy2DgMAdMCYAZb+CSN/7RAi+cqzpxA5yff23k9QJFDbbQBlMCiK6G4zY0/1RdevDAMtX1z/kfsDRx5P+/gEpLK6MpzD0IabH9YdTH+f+aruYWO0Eyt6NfyiZu3FLQZp52+9gSdG7AROXE+P0q2/f0hFj6/l+BqvJaHwIv/hYVhKywCNsDpQfnWSYCdsijs1HnicFDgZs2VCKiC0JQMQSIAm+dj9t+p5x2bftnUkyDtvX47GTVp6wcsKn4JskYbZFdpxnydxE/lgyJiDOTmE89m0Aa7KlPgkTZ1WwDVAOPWSeBlAiXnmTlESk+zKZUg+EFtgmo31fWuq0+Zg0wcMeLNEX+8WkxjCpsg0/Z8Lkbk5d+CnYMlAKjexCinYl96jUxpRPBCCmlLEAhQ2fnPVhnGVmF9NEtPTumwXrToR0m070ceoiqBpAHaUVIh7/5JjGYB0wcpQnlvResnp8uIlqB5GeAAMgAiDGK+r1Tt0l6UQfOyErzNI3GAU5zstBV0DLWboSDCcmfL+nHwGUAcrvZbtttQDSpKhHZhOjhU59E4F2MKqlF1BONQ40AZS4cmvDYAOo+uyZc2TRJ9EKaQORPo3Xtw50eBGqG9v/7aBCaSw9QEn0YhRlMoLS5eo0M6L2LGbAmUkRnVlKPi23IGMs7MlEPVUZ4+1dTUBhk3zayajnUHPkzKgZAiTgaJOgUCy+Kgo+05V93r4juBAAw7DG04d+MFTV0vNoAygN3BJJCaQnBvtMAZsMqb5eHLsB2C1Zpz/7appg7jOBScbzrQeR+tJkGE8/WYJDutITJS395rCKA5OiuOOwhQpIQ3F6ZzKksBKsA3WQG8A8teTuNkwYF0luIt0AxSb7PSmSzQcCKQloLEJPsuU2CZASIPXyGAczjMHPMnsGTMBp9++tjafcB8CAZZJt1unn/Mv1hPSkZc9LT+Hp11kbwIxQzB3HjZpCDxCM6N1YA6wAwxAgfDLOGm2xD8lBqL4EDmFyuk9hm1ghZpAM1FGmwtmUmyFXWm6LfIgSzV4BIeHQcmLbZHW0n8FE4PGagZyfHPkYvkcXu5d2vTjheKZlLGzqOh2XveMqQuGwyvGKgVxpyz06+10SuQFGnK19O231fgrh8MjrtYlp9z58FJDo8e9bjGKDLIDLkctZ8vJAkoHqOMUA+QfXApI/ChpACyPKl4Agzax7By5LM8zT2yxLaDwrILC6IJKfnU1upCnJs+Sw+cxHEdEMqwQWLkCa0DU5s5F8jADxAKPd3gEU/ylhFfpe92BK3zAZr5di7TCODWwRI9yAFe2UZ0BLYSaAhV18hjMiqUO51Y0C2IzlCRQSVyC1p0mVfTxh0kHaqnH+5IiJTf1LiOwMFGEbqyYfPL+hGHa54zTAGOjG4eIFYYIKHMT/3jGQ5G7ZK8GV0gkUoQB4Vlfus35FsCutjHDH0R1JR0DYa+/zmhCiFITf45Mst5ikdOGQvAhUgs+wvfLnAAHGlRZ2BZgrS13HP8nkhxFY3FJpw200nhREdBM4+KSYxBalDKBStgKlEGBEIsxywiKFkJj1t6PSWLf0fWIA5BtYxJ1YKUgAWFm+CaiWhqfSF2zgXxxiCDhOPAhHNAKEOk+AsS3zHXWyCRsLE1dabNujtNu3Ai0FA0pf+h+AOqDFtA42Ek5BHDAAyreAI5nrMNRlp0t2AhqVNncKCkbLDIEAonxHNE6JnO/jksc6pdTdJV/FaJdg8DVhzC5Atsk3A+2S/wNYU3rhC7E8UDjURuIvAAAAAElFTkSuQmCC
" alt="Smiley face" width="42" height="42">

</body>
</html>