We Keep Coding

HTTP POST Request with Json body giving error code 400

I'm trying to send a Json format in body of POST request in java.
I tried a lot of codes from the internet and StackOverflow, but nothing is working.
I keep getting java.io.IOException: Server returned HTTP response code: 400 for URL: http://localhost:8080/engine-rest/message.
After trying a lot on Postman i noticed it only accepts Json format body, i tried using json libraries like Gson, yet still nothing worked.
Any ideas on how to fix my code? Again I did try to copy a lot of codes from the internet so please don't send me a similar title stackoverflow thread and call the question repetitive.
Thank you in advance.
public class PostRequest {
FileWriter myWriter;
URL url;
public void sendPost(String Url) throws IOException {
String name = "{\"messageName\": \"URLFound\", \"businessKey\": \"3\"}";
try {
myWriter = new FileWriter("C:\\Users\\test\\Desktop\\camunda test save\\Post.txt");
url = new URL ("http://localhost:8080/engine-rest" + Url);
HttpURLConnection http = (HttpURLConnection)url.openConnection();
http.setRequestMethod("POST");
http.setDoOutput(true);
http.setRequestProperty("Content-Type", "application/json");
OutputStream os = http.getOutputStream();
byte[] input = name.getBytes("utf-8");
os.write(input, 0, input.length);
BufferedReader in = new BufferedReader(new InputStreamReader(http.getInputStream()));
StringBuffer response = new StringBuffer();
while ((in.ready())) {
response.append(in.readLine());
}
in.close();
//Writing result on .txt
myWriter.append(response.toString() + "\n" +url);
}
catch(Exception e){
myWriter.append(e.toString());
}
myWriter.close();
}
}

How about using this client project?
https://github.com/camunda-community-hub/camunda-rest-client-spring-boot/
For example:
https://github.com/camunda-community-hub/camunda-rest-client-spring-boot/blob/dce6bd777e3350dd30286311c5351aa9460a34f4/examples/example/src/main/java/org/camunda/bpm/extension/rest/example/standalone/client/ProcessClient.java#L98

Java cant create an object from your json. Check if all fields are sent in the request body of the java class that is expected on the backend side.

How do I get key and value of form-data from Post HTTP on Java using Servlet? [duplicate]

This question already has answers here:
How can I upload files to a server using JSP/Servlet?
(14 answers)
Closed 1 year ago.
I'm developing a Backend application using Java and Servlet.
I'm using Postman to simulate my client that will send me POST requests.
The thing is, my Client will send me data (key and value) using the HTTP Body part rather than params. On postman I can simulate it filling KEY and VALUE on the Body part as form-data. On the server side, people recommend this:
String login = request.getParameter("login");
But since the client is sending the parameters to me using the body, the above function returns me null (only works if I use params tab on Postman, which is not my client behavior). I was able to read the body using:
String line = null;
while ((line = request.getReader().readLine()) != null)
System.out.println(line);
But the data I get is like:
----------------------------655577064367924555315251
Content-Disposition: form-data; name="login"
matheus
Which means that I'd have to parse that string to transform it on a map<String,String>, which I'm pretty sure that it's not the best whey to handle it.
There is any way that I can pass a KEY("login") to retrieve the VALUE(matheus) from the Body as made on params?
*** SOLUTION ***
It was missing the annotation:
#MultipartConfig

you can do it like this;
#PostMapping("/")
public #ResponseBody
String greetingPost(HttpServletRequest httpRequest) throws Exception {
final StringBuffer ret = new StringBuffer();
httpRequest.getParts().stream().forEach(part -> {
try {
ret.append(part.getName())
.append(":")
.append(IOUtils.toString(part.getInputStream(), "UTF8"))
.append("\n");
} catch (IOException e) {
e.printStackTrace();
}
});
return ret.toString();
}

Getting Error 405 for post request to REST api using Java Jersey api

I wrote a method using Jersey API to make a post request to an api. The api requires the data being posted be in JSON format and has requires a Basic Authorization header however when I run the code below and pass the object it results in the following error
java.lang.RuntimeException: Failed : HTTP error code : 405
at com.shumbamoney.yomoney.SendRequest.send(SendRequest.java:40)
.The java code is below.
public String send(TransactionRequestObject tRObject){
Gson gson = new Gson();
Gson gsonBuilder = new GsonBuilder().create();
String jsonRObject = gsonBuilder.toJson(tRObject);
ApiCredentials credentials = new ApiCredentials();
postUrl = credentials.getURL();
AgentCode = credentials.getAgentCode();
Password = credentials.getPassword();
System.out.println(jsonRObject);
// jersey code
try{
Client client = Client.create();
WebResource webResource = client.resource(postUrl);
ClientResponse response = webResource.type("application/json; charset=ISO-8859-1").header(HttpHeaders.AUTHORIZATION, "Basic "+
AgentCode+":"+Password).post(ClientResponse.class, jsonRObject);
if (response.getStatus() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ response.getStatus());
}
System.out.println("Output from Server .... \n");
String output = response.getEntity(String.class);
System.out.println(output);
}catch(Exception e){
e.printStackTrace();
}
return "success";
}
Your help is greatly appreciated.

your code did all the things it should: send the request and get the response from the API, so the error doesn't come from your code, it's from the server that you are requesting to.
try using postman to POST to that url, if you still get the 405 error, than you can make sure that the problem is not from ur code.

Thank you everyone for your contributions I really appreciate them. It turns out the issue was on the server that I was requesting to.

Authenticate with CouchDB and insert new database via HTTP PUT in Android app

I am implementing an Android app that should upload data to CouchDB. Since I have restricted the admin access to one account, I have to authenticate before inserting a new database. And this is what I am currently struggling with: Authenticate and insert a new database. Operating via Terminal and using curl, everything is working out fine the following way:
> curl -X PUT http://admin_name:admin_password#url:port/database_to_be_inserted
First approach
My first approach was to simply do the same via HTTP PUT in my code like that:
private boolean putJSON(String json, String url) {
// url = http://admin_name:admin_password#url:port/database_to_be_inserted
HttpClient client = new DefaultHttpClient();
HttpPut put = new HttpPut(url);
try {
StringEntity stringEntity = new StringEntity(json,"utf-8");
put.setEntity(stringEntity);
put.setHeader("Content-type", "application/json; charset=utf-8");
put.setHeader("Accept", "application/json");
HttpResponse response = client.execute(put);
// ... buffered input reading on response...
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
However, doing so I retrieve the following error and JSON array:
Authentication error: Unable to respond to any of these challenges: {}
{"error":"unauthorized","reason":"You are not a server admin."}
The point is, that using the same method for inserting a new user works out perfectly. So, if I am using the above method with a correctly formatted user JSON-Dictionary and the following url, the user is inserted correctly.
http://admin_name:admin_password#url:port/_users/org.couchdb.user:user_name
This should prove, that I am using the right admin data at least, shouldn't it?
Second approach
So, by now, I am trying to authenticate using the "Authorization" option in my HTTP PUT's header:
private boolean putDatabase(String userName, String password, String url) {
// url = "http://url:port/database_to_be_inserted"
HttpClient client = new DefaultHttpClient();
HttpPut put = new HttpPut(url);
String authenticationData = userName+":"+password;
String encoding = Base64.encodeToString(authenticationData.getBytes(Charset.forName("utf-8")), Base64.DEFAULT);
put.setHeader("Authorization", "Basic " + encoding);
try {
put.setHeader("Content-type", "application/json; charset=utf-8");
put.setHeader("Accept", "application/json");
HttpResponse response = client.execute(put);
// ... buffered input reading on response...
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
Still no success in inserting the database. The response I am parsing says:
Host not found
I have double checked the admin name, password, and url and everything seems correct. Does anyone of you see why this might not work out?

Ok, the answer is simple: The above code (at least the one of my second approach) is working fine. My mistake was to not explicitly specify the port via which the CouchDB should be accessed. This is, how I accidentally called the method:
putDatabase("adminName", "adminPassword", "http://url/database_to_be_inserted");
However, this is how I should have called it:
putDatabase("adminName", "adminPassword", "http://url:port/database_to_be_inserted");
Who is using iriscouch like me and does not know which port to specify here, can look it up in the config file. Using Futon this can be found in the entry "httpd > port" here:
> http://your_url_spec.iriscouch.com/_utils/config.html
More general and without Futon this can be found (and if you wish so edited) via command-line in the local.ini of your own CouchDB installation:
~$ cat etc/couchdb/local.ini

How to send a JSONObject to a REST service?

Retrieving data from the REST Server works well, but if I want to post an object it doesn't work:
public static void postJSONObject(int store_type, FavoriteItem favorite, String token, String objectName) {
String url = "";
switch(store_type) {
case STORE_PROJECT:
url = URL_STORE_PROJECT_PART1 + token + URL_STORE_PROJECT_PART2;
//data = favorite.getAsJSONObject();
break;
}
HttpClient httpClient = new DefaultHttpClient();
HttpPost postMethod = new HttpPost(url);
try {
HttpEntity entity = new StringEntity("{\"ID\":0,\"Name\":\"Mein Projekt10\"}");
postMethod.setEntity(entity);
HttpResponse response = httpClient.execute(postMethod);
Log.i("JSONStore", "Post request, to URL: " + url);
System.out.println("Status code: " + response.getStatusLine().getStatusCode());
} catch (ClientProtocolException e) {
I always get a 400 Error Code. Does anybody know whats wrong?
I have working C# code, but I can't convert:
System.Net.WebRequest wr = System.Net.HttpWebRequest.Create("http://localhost:51273/WSUser.svc/pak3omxtEuLrzHSUSbQP/project");
wr.Method = "POST";
string data = "{\"ID\":1,\"Name\":\"Mein Projekt\"}";
byte [] d = UTF8Encoding.UTF8.GetBytes(data);
wr.ContentLength = d.Length;
wr.ContentType = "application/json";
wr.GetRequestStream().Write(d, 0, d.Length);
System.Net.WebResponse wresp = wr.GetResponse();
System.IO.StreamReader sr = new System.IO.StreamReader(wresp.GetResponseStream());
string line = sr.ReadToEnd();

Try setting the content type header:
postMethod.addRequestHeader("Content-Type", "application/json");
Btw, I strongly recommend Jersey. It has a REST client library which makes these kind of things much easier and more readable

Your C# is different than your Java, and not just in syntax.
Your C# sends an application/json entity to the server via HTTP POST. I'll leave it up to HTTP purists as to whether that's appropriate use of POST (vs. PUT).
Your Java creates a form, with a field of jsonString (whose value is the JSON), and sends an application/x-www-form-urlencoded entity to the server containing that form.

I would go right to the server err_log or equivelant error log. The server knows why it rejected your request. If you don't have access, set up your own test server and duplicate the issue there so you can review the logs =)