java下载base64图片

可以使用 Java 的 URL 和 HttpURLConnection 对象来下载 base64 图片：

import java.net.URL;
import java.net.HttpURLConnection;
import java.util.Base64;

public class DownloadBase64Image {

    public static void main(String[] args) throws Exception {
        String base64 = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAACjElEQVR4nK2TwW4bRxiHn7MvkNLdPnj9klvX8SQ31WKNhe1EiFQVNk..."; // base64 string
        String[] parts = base64.split(",");
        String contentType = parts[0].split(";")[0].split(":")[1];
        String imageData = parts[1];
        byte[] decoded = Base64.getDecoder().decode(imageData.getBytes());
        
        URL url = new URL("https://example.com/image.png");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("PUT");
        connection.setRequestProperty("Content-Type", contentType);
        connection.setRequestProperty("Content-Length", String.valueOf(decoded.length));
        connection.setDoOutput(true);
        connection.getOutputStream().write(decoded);
        
        int responseCode = connection.getResponseCode();
        System.out.println("Response Code : " + responseCode);
    }
}

这个程序将从 base64 图片中提取图片数据并使用 HttpURLConnection 将其上传到指定的 URL。你需要替换 url 和 content-type，以确保这个程序运行在你的环境中。