Java调用Zoom API发送文件遇405错误求助

已完成Zoom OAuth服务端到服务端认证，应用拥有/chat_message:write:admin权限，且能正常发送普通聊天消息。持有有效token、自身用户ID和接收方ID，但用Java程序发送label.pdf文件时，返回405 Method Not Allowed错误。

相关代码 #

private static final String API_ENDPOINT = "https://api.zoom.us/v2/chat/users/";

// Create API URL
URL url = new URL(API_ENDPOINT + userId + "/messages/files");
// Open connection and set request properties
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Authorization", "Bearer " + token);
conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=boundary");
byte[] pdfData = Files.readAllBytes(new File(filePath).toPath());
String boundary = "boundary";
String delimiter = "--" + boundary + "\n";
StringBuilder builder = new StringBuilder();
builder.append(delimiter);
builder.append("Content-Disposition: form-data; name=\"to_contact\"\n\n");
builder.append(toContact+"\n");
builder.append(delimiter);
builder.append("Content-Disposition: form-data; name=\"files\"; filename=\"label\"\n");
builder.append("Content-Type: application/pdf\n");
builder.append("\n");
builder.append(new String(pdfData, "ISO-8859-1"));
builder.append("\n");
builder.append("--" + boundary + "--");
conn.setDoOutput(true);
String multipartData = builder.toString();
System.out.println(multipartData);
conn.getOutputStream().write(multipartData.getBytes("UTF-8"));
// Send request and get response code and message
conn.connect();
int responseCode = conn.getResponseCode();
String responseMessage = conn.getResponseMessage();
// Check if response is successful
if (Arrays.asList(RESPONSE_CODE).contains(Integer.toString(responseCode))) {
    System.out.println("File sent successfully!");
    System.out.println("Response code: " + responseCode);
    System.out.println("Response message: " + responseMessage);
} else {
    System.out.println("Error sending file:");
    System.out.println("Response code: " + responseCode);
    System.out.println("Response message: " + responseMessage);
}
// Close connection
conn.disconnect();

• API端点错误：发送聊天文件的正确Zoom API端点是https://api.zoom.us/v2/chat/users/{userId}/messages，你代码中使用的/messages/files是无效路径，服务器无法识别该路径的POST请求，因此返回405错误。

• 二进制数据处理问题：将PDF二进制数据转成ISO-8859-1字符串再转成UTF-8字节的操作会损坏二进制文件，正确做法是直接写入原始二进制数据，避免字符串中转。

• 边界一致性优化：虽然不是405错误的直接原因，但要确保Content-Type头中指定的boundary值与实际构建表单时使用的分隔符完全一致，避免后续表单解析失败。

修正后的关键代码示例 #

修正端点 #

URL url = new URL(API_ENDPOINT + userId + "/messages");

正确处理二进制数据写入 #

OutputStream os = conn.getOutputStream();
// 写入收件人参数
os.write(delimiter.getBytes("UTF-8"));
os.write("Content-Disposition: form-data; name=\"to_contact\"\n\n".getBytes("UTF-8"));
os.write((toContact + "\n").getBytes("UTF-8"));
// 写入文件部分
os.write(delimiter.getBytes("UTF-8"));
os.write("Content-Disposition: form-data; name=\"files\"; filename=\"label.pdf\"\n".getBytes("UTF-8"));
os.write("Content-Type: application/pdf\n\n".getBytes("UTF-8"));
// 直接写入PDF二进制数据，不经过字符串转换
os.write(pdfData);
// 写入结束边界
os.write(("\n--" + boundary + "--").getBytes("UTF-8"));
os.flush();

内容的提问来源于stack exchange，提问作者AndreaTaroni86