java上传图片到服务器，并返回可访问图片的url地址

在Java中，你可以使用HttpURLConnection或者第三方库如Apache HttpClient来上传图片到服务器，并返回可访问图片的URL地址。以下是使用HttpURLConnection的一个简单示例：

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
 
public class ImageUploader {
 
    public static void uploadImage(String targetUrl, File imageFile) throws IOException {
        String boundary = Long.toHexString(System.currentTimeMillis()); // 随机边界
        String CRLF = "\r\n"; // 换行符
        String charset = "UTF-8"; // 设置编码
 
        URL url = new URL(targetUrl);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setDoOutput(true);
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
 
        try (
            OutputStream output = connection.getOutputStream();
            PrintWriter writer = new PrintWriter(new OutputStreamWriter(output, charset), true);
        ) {
            // 发送文件数据
            writer.append("--" + boundary).append(CRLF);
            writer.append("Content-Disposition: form-data; name=\"image\"; filename=\"" + imageFile.getName() + "\"").append(CRLF);
            writer.append("Content-Type: " + URLConnection.guessContentTypeFromName(imageFile.getName())).append(CRLF);
            writer.append(CRLF).flush();
 
            Files.copy(imageFile.toPath(), output);
            output.flush(); // 确保图片数据被发送
 
            writer.append(CRLF).flush(); // 结束标记
 
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        int responseCode = connection.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            try (BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
                String inputLine;
                StringBuilder response = new StringBuilder();
 
                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }
 
                // 打印服务器回传的可访问图片URL地址
                System.out.println(response.toS