java调用post接口获取图纸PDF

好的，我理解了你的要求。为了调用post接口获取图纸PDF，你需要使用Java的HttpURLConnection来发送post请求，并且需要进行身份验证，传递参数，并获取响应。你可以先创建一个URL对象，然后使用HttpURLConnection.openConnection()方法创建连接。接着，你可以使用HttpURLConnection.setRequestMethod("POST")方法设置请求方法为POST，并使用HttpURLConnection.setRequestProperty()方法设置请求头部信息。最后，你需要获取响应信息，并将其转换成PDF格式保存。具体实现代码如下：

import java.io.*;
import java.net.*;
import javax.net.ssl.HttpsURLConnection;

public class PostRequestExample{

  public static void main(String[] args) {

    String url = "http://example.com/api/get_pdf";
    String params = "fileId=1234&accessToken=abcd1234";
    String saveFilePath = "C:/pdfs/file.pdf";

    try {
      URL obj = new URL(url);
      HttpsURLConnection conn = (HttpsURLConnection) obj.openConnection();

      // Header
      conn.setRequestMethod("POST");
      conn.setRequestProperty("User-Agent", "Mozilla/5.0");
      conn.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
      conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

      // Body
      conn.setDoOutput(true);
      OutputStreamWriter os = new OutputStreamWriter(conn.getOutputStream());
      os.write(params);
      os.flush();
      os.close();

      // Response
      int responseCode = conn.getResponseCode();

      if (responseCode == HttpURLConnection.HTTP_OK) { // success

        InputStream inputStream = conn.getInputStream();
        OutputStream outputStream = new FileOutputStream(new File(saveFilePath));

        byte[] buffer = new byte[2048];
        int len;
        while ((len = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, len);
        }

        outputStream.close();
        inputStream.close();

        System.out.println("PDF 文件下载成功");

      } else {
        System.out.println("PDF 文件下载失败: " + responseCode);
      }

    } catch (Exception e) {
      e.printStackTrace();
    }

  }
}