如何在java中将图像转换为base64字符串？
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How to convert an Image to base64 string in java?
提问by Setu Kumar Basak
It may be a duplicate but i am facing some problem to convert the image into Base64for sending it for Http Post. I have tried this code but it gave me wrong encoded string.
它可能是重复的，但我在将图像转换Base64为用于发送时遇到了一些问题Http Post。我试过这段代码，但它给了我错误的编码字符串。
public static void main(String[] args) {
File f = new File("C:/Users/SETU BASAK/Desktop/a.jpg");
String encodstring = encodeFileToBase64Binary(f);
System.out.println(encodstring);
}
private static String encodeFileToBase64Binary(File file){
String encodedfile = null;
try {
FileInputStream fileInputStreamReader = new FileInputStream(file);
byte[] bytes = new byte[(int)file.length()];
fileInputStreamReader.read(bytes);
encodedfile = Base64.encodeBase64(bytes).toString();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return encodedfile;
}
Output:[B@677327b6
But i converted this same image into Base64in many online encoders and they all gave the correct big Base64 string.
输出：[B@677327b6
但我Base64在许多在线编码器中转换了相同的图像，它们都给出了正确的大 Base64 字符串。
Edit:How is it a duplicate?? The link which is duplicate of mine doesn't give me solution of converting the string what i wanted.
编辑：它是如何重复的？我的重复链接没有给我转换我想要的字符串的解决方案。
What am i missing here??
我在这里错过了什么？
采纳答案by Lolo
The problem is that you are returning the toString()of the call to Base64.encodeBase64(bytes)which returns a byte array. So what you get in the end is the default string representation of a byte array, which corresponds to the output you get.
问题是您正在返回返回字节数组toString()的调用的Base64.encodeBase64(bytes)。所以你最终得到的是一个字节数组的默认字符串表示，它对应于你得到的输出。
Instead, you should do:
相反，你应该这样做：
encodedfile = new String(Base64.encodeBase64(bytes), "UTF-8");
回答by MojioMS
this did it for me. you can vary the options for the output format to Base64.Default whatsoever.
这是为我做的。您可以将输出格式的选项更改为 Base64.Default。
// encode base64 from image
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] b = baos.toByteArray();
encodedString = Base64.encodeToString(b, Base64.URL_SAFE | Base64.NO_WRAP);
回答by Joels Elf
I think you might want:
我想你可能想要：
String encodedFile = Base64.getEncoder().encodeToString(bytes);
