【Java】OSS PostObject未发生回调的问题排查今天排查一个问题，走了一些弯路，总结一下，希望可以为后来者提

今天排查一个问题，走了一些弯路，总结一下，希望可以为后来者提供参考建议。

问题：

XX反馈，使用OSS PostObject的callback没有发生回调。但是通过putobject用同样的callback是有回调发生的。客户怀疑我们的PostObject有问题。

排查：

OSS回调流程为客户端->OSS->应用服务器->客户端

创建一台ECS用于当测试应用服务器
创建一个asp.net 的ashx，代码自行实现，用于获取OSS callback参数。
写了两个上传demo

Putobject （SDK上有示例help.aliyun.com/document_de…）

PutObjectRequest putObjectRequest=new PutObjectRequest(bucketName, key, new ByteArrayInputStream(content.getBytes()), meta);
Callback callback = new Callback();
callback.setCallbackUrl("http://接收端IP/Revice.ashx ");
callback.setCallbackBody("{\\\ "mimeType\\\":${mimeType},\\\ "size\\\":${size}} ");
putObjectRequest.setCallback(callback);
        
ossClient.putObject(putObjectRequest)

postobject（post demo，参考github.com/aliyun/aliy…）

关键代码：

File file = new File(localFile);
String filename = file.getName();
String contentType = new MimetypesFileTypeMap().getContentType(file);
if (contentType == null || contentType.equals(" ")) {
     contentType = "application/octet-stream ";
}

StringBuffer strBuf = new StringBuffer();
strBuf.append("\r\n ").append("-- ").append(boundary).append("\r\n ");
strBuf.append("Content-Disposition: form-data; name=\ "file\"; "+ "filename=\ "" + filename + "\"\r\n ");
strBuf.append("Content-Type: " + contentType + "\r\n\r\n ");
out.write(strBuf.toString().getBytes());

//callback部分
StringBuffer strBuf1 = new StringBuffer();
String callback="{\ "callbackUrl\":\ "http://应用接收端IP/Revice.ashx\",\ "callbackBody\":\ "{\\\"bucket\\\ "=${bucket},\\\"size\\\ "=${size}}\"} ";
byte[] textByte = callback.getBytes("UTF-8 ");
strBuf1.append("\r\n ").append("-- ").append(boundary).append("\r\n ");
String callbackstr=new String(Base64.encodeBase64(textByte));
strBuf1.append("Content-Disposition: form-data; name=\ "callback\"\r\n\r\n " + callbackstr  + "\r\n\r\n ");
out.write(strBuf1.toString().getBytes());
//callback部分
     
DataInputStream in = new DataInputStream(new FileInputStream(file));
int bytes = 0;
byte[] bufferOut = new byte[1024];
while ((bytes = in.read(bufferOut)) != -1) {
     out.write(bufferOut, 0, bytes);
}
in.close();

byte[] endData = ("\r\n-- " + boundary + "--\r\n ").getBytes();
out.write(endData);
out.flush();
out.close();