java post下载文件

在Java中，你可以使用HttpURLConnection或者第三方库如Apache HttpClient或者OkHttp来进行POST请求并下载文件。这里是一个基本的例子，使用HttpURLConnection：

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class DownloadFile {
    public static void main(String[] args) throws IOException {
        String url = "http://example.com/file-to-download.zip"; // 替换为你需要下载的文件URL

        try (BufferedInputStream in = new BufferedInputStream(
                new URL(url).openStream())) {

            File file = new File("downloaded-file.zip"); // 文件保存路径
            FileOutputStream out = new FileOutputStream(file);

            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }

            out.close();
            in.close();

            System.out.println("Download complete.");
        } catch (IOException e) {
            System.err.println("Error occurred during download: " + e.getMessage());
        }
    }
}

这个例子首先创建一个URL对象，并通过`openStream()`方法获取到连接到服务器的输入流。然后，将输入流读取的数据写入本地文件中。最后关闭流以释放资源。