Java - 将图像转换为 Base64 [英] Java - Convert image to Base64
问题描述
我在将 gif 图像转换为 base 64 字符串时遇到问题.
I'm having a problem while converting a gif image to a base 64 string.
当我转换它时，代码给我加上了 100,000 AAAAAA 而图像真的很小！
When I converts it, the code adds me like 100,000 AAAAAA whereas the image is really small!
这是我的代码:
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.util.ArrayList;
public class Main
{
public static void main(String[] args)
{
try
{
FileWriter fstream = new FileWriter("./out.txt");
BufferedWriter out = new BufferedWriter(fstream);
File folder = new File("./flags/");
File[] listOfFiles = folder.listFiles();
for (int i = 0; i < listOfFiles.length; i++)
{
if (listOfFiles[i].isFile())
{
Main.readFile(out, listOfFiles[i]);
}
}
out.close();
System.out.println("Done");
}
catch (Exception e) {}
}
public static void readFile(BufferedWriter out, File file)
{
try
{
byte[] byteArray = new byte[102400];
FileInputStream fis = new FileInputStream(file);
String base64String;
int bytesRead = 0;
while ((bytesRead = fis.read(byteArray)) != -1)
{
new String(byteArray, 0, bytesRead);
base64String = Base64.encode(byteArray);
out.write("public static ImageIcon getFlag" + file.getName() + "()");
out.newLine();
out.write("{");
out.newLine();
ArrayList<String> array = Main.cut(base64String);
out.write("return Utils.toImage("" + array.get(0) + """);
for (int i=1; i<array.size()-1; i++)
{
out.write("<tab>+"" + array.get(i) + """);
}
out.write("<tab>"" + array.get(array.size() - 1) + "");");
out.newLine();
out.write("}");
out.newLine();
out.newLine();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
public static ArrayList<String> cut(String in)
{
ArrayList<String> array = new ArrayList<String>();
while (in.length() > 76)
{
array.add( in.substring(0, 77) );
in = in.substring(77);
}
return array;
}
}
基本上，它在一个文本文件out.txt中写入了一堆Java方法，里面有base 64代码.
Basicaly, it writes in a text file out.txt a bunch of java methods with the base 64 code inside.
这是输出的(小)部分:
Here is a (small) part of the output:
<代码>返回Utils.toImage( R0lGODlhEAALANUAANPTAPZva/n5AfLySPz8iYqY3O01NgoksbGZa + kYGOskJKi05vb2XZ + R4 + 05O" <标签> + Pv7eO3tKPv7bZak4dSvebC76tC2iPNISPX1UMkAAMm6U/NWTeYAAF5y1LqlevNaWpSh3e7uQ + 1CQt" <标签> + gAAKOv5Vds1C1IvpGf37a/7OnTYZ6q6NGkamd71/LyPusvLvFiTEFbx9rPb/HuaczATd7eAPAAAH2" <标签> + N2vE + PMqiYuXQUsKufJqn4jlRxUlhy + CpelFnz/PxbyH5BAAAAAAALAAAAAAQAAsAAAaQwBVnSBIY" <标签> + jzTaZsk5OSmEKOHxCAQ8nk1zMUo9Ir8Y42Kx2Dyi5qihi1QqkxzZZtCISBS2JNILoFQDdC0WIj4UO" <标签> + hImDBMoLjcsBi0KISI8C4kFMB0uOAgykgkOGC8LJgUFFx0IqxAKCQkGGDsjpzUDLBkZEBCvCS0YJW" <标签> + wfBQxjAyAgDpG/OwfOBzPRANMY1dVBADsAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签>+"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"<tab>+"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"<标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"<标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"<标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" <标签> +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA <标签> +" AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA<标签>
谢谢.
我正在使用这个问题中的 base64 代码:https://stackoverflow.com/a/4265472/1295422
I'm using the base64 code from this question: https://stackoverflow.com/a/4265472/1295422
推荐答案
byte[] byteArray = new byte[102400];
base64String = Base64.encode(byteArray);
无论您在数组中实际使用多少数据，该代码都将编码 102400 个字节.
That code will encode 102400 bytes, no matter how much data you actually use in the array.
while ((bytesRead = fis.read(byteArray)) != -1)
您需要在某处使用 bytesRead 的值.
You need to use the value of bytesRead somewhere.
此外，这可能不会一次性将整个文件读入数组(它只会读取 I/O 缓冲区中的内容)，因此您的循环可能无法正常工作，您最终可能会得到一半图像在你的数组中.
Also, this may not read the whole file into the array in one go (it only reads as much as is in the I/O buffer), so your loop will probably not work, you may end up with half an image in your array.
我会在这里使用 Apache Commons IOUtils:
I'd use Apache Commons IOUtils here:
Base64.encode(FileUtils.readFileToByteArray(file));
这篇关于Java - 将图像转换为 Base64的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
