SN Singh SN Singh - 2 months ago 21
Java Question

Getting error while using PATCH method in HttpURLConnection

Here from the last few hours, I am trying to update some field of resource using

HttpURLConnection
PUT method. But now I've changed this to PATCH.

I am able to perform
GET
and
POST
, but in Http method
PATCH
keep getting error.

The request not even being sent in
POSTMAN
.

This is the
java
class:

try {
String serUrl = "https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/255";
String authString = user + ":" + password;
byte[] authEncBytes = Base64.getEncoder().encode(authString.getBytes());
String authStringEnc = new String(authEncBytes);

URL url = new URL(serUrl); //Enter URL here
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setDoInput(true);
httpURLConnection.setDoOutput(true);
httpURLConnection.setRequestProperty("X-HTTP-Method-Override", "PATCH");
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setRequestProperty("Authorization", "Basic " + authStringEnc);
httpURLConnection.setRequestProperty("Content-Type", "application/json");

httpURLConnection.connect();

String inputJson = "{ \"id\":" + 255 + "," +
"\"assignedToAccount\": {" +
" \"id\":" + 233 +
" }," +
" \"name\":\"" + "task2_checking34" + "\"," +
" \"serviceSettings\":{" +
" \"incident\":{" +
" \"id\":" + 380 +
" }" +
" }" +
"}";
OutputStreamWriter osw = new OutputStreamWriter(httpURLConnection.getOutputStream());
osw.write(inputJson);
osw.flush();
osw.close();

BufferedReader br = new BufferedReader(new InputStreamReader(
(httpURLConnection.getInputStream())));

String output;
StringBuffer bfr = new StringBuffer();
String res = "";
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
bfr.append(output);
}
res = bfr.toString();

} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}


The idea of using
PATCH
method in
HttpUrlConnection
by overriding the
POST
got from here.

I got the idea of sending parameters in the request body got from here.

The resources available at this url
https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/
are like

{
"id": 253,
"lookupName": "task_quality34",
"createdTime": "2017-08-03T05:34:34Z",
"updatedTime": "2017-08-03T05:34:34Z",
"links": [{
"rel": "canonical",
"href": "https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/253"
}]
}, {
"id": 255,
"lookupName": "task_quality-test12",
"createdTime": "2017-08-03T05:48:26Z",
"updatedTime": "2017-08-03T05:48:26Z",
"links": [{
"rel": "canonical",
"href": "https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/255"
}]
}


And I am trying to
update
some field of this resource , using PATCH method at this url
https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/255


But every time I am getting error

java.io.IOException: Server returned HTTP response code: 400 for URL: https://lavazzaindia--tst1.custhelp.com/services/rest/connect/latest/tasks/255
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at com.cloud.task.TaskUpdate.main(TaskUpdate.java:80)


Please someone help me out here to fix this.

Answer Source

Well, I'm answering own question.

I just modified few lines of code and it worked for me. Following is the working code:

        try {
            URL url = new URL(serUrl); //Enter URL here
            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setRequestProperty("Authorization", "Basic " + authStringEnc);
            httpURLConnection.setRequestProperty("Accept", "application/json");
            httpURLConnection.setRequestProperty("Content-Type", "application/json");
            httpURLConnection.setRequestProperty("X-HTTP-Method-Override", "PATCH");
            httpURLConnection.connect();

            DataOutputStream wr = new DataOutputStream(httpURLConnection.getOutputStream());
            wr.write(inputJson.getBytes());
            wr.flush();
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    (httpURLConnection.getInputStream())));


            StringBuffer bfr = new StringBuffer();
            String output = "";
            String res = "";

            while ((output = br.readLine()) != null) {
                bfr.append(output);
            }
            resCode = httpURLConnection.getResponseCode();
//            System.out.println("response code = "+resCode);
            if (resCode != 200) {
                throw new RuntimeException("Failed : HTTP error code : "
                        + resCode +"\n"
                        +bfr.toString());
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

In the variable inputJson we shouldn't send the parameter id while it's already in the url.

I was keep trying with the numbers of example programs, and finally resource was getting updated.