Develop Reference

Get list of bindings for RabbitMQ

We have a RabbitMQ Broker (V3.5.7) which is routing messages to a group of servers. When a server instance comes up (perhaps after a restart), I would like get a list of the current bindings for that server, so that I can confirm the bindings. The server is running Java, so that would be the preferred API.

It is an http call, something like that:
HttpURLConnection connection = null;
try {
//Create connection
URL url = new URL("http://localhost:15672/api/exchanges/%2F/topic_test/bindings/source");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
connection.setRequestProperty("Content-Language", "en-US");
String userpass = "guest:guest";
String basicAuth = "Basic " + new String(Base64.getEncoder().encode(userpass.getBytes()));
connection.setRequestProperty ("Authorization", basicAuth);
connection.setUseCaches(false);
connection.setDoOutput(true);
//Get Response
InputStream is = connection.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
StringBuilder response = new StringBuilder(); // or StringBuffer if Java version 5+
String line;
while ((line = rd.readLine()) != null) {
response.append(line);
response.append('\r');
}
rd.close();
System.out.println(response.toString());
} catch (Exception e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
}
maybe there are more efficient ways, but this is the idea

Java code to login to website which contains emailId in page and password in another page

I want to write a Java application, which can login to a website For example, www.tumblr.com/login. Basically this web page asks for an email address on the first page and then would take the user to the next page to enter the password.
Can someone please help me with a sample Java code for this problem?

You might want to look at HttpURLConnection
public static String executePost(String targetURL, String urlParameters) {
HttpURLConnection connection = null;
try {
//Create connection
URL url = new URL(targetURL);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
connection.setRequestProperty("Content-Length",
Integer.toString(urlParameters.getBytes().length));
connection.setRequestProperty("Content-Language", "en-US");
connection.setUseCaches(false);
connection.setDoOutput(true);
//Send request
DataOutputStream wr = new DataOutputStream (
connection.getOutputStream());
wr.writeBytes(urlParameters);
wr.close();
//Get Response
InputStream is = connection.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
StringBuilder response = new StringBuilder(); // or StringBuffer if Java version 5+
String line;
while ((line = rd.readLine()) != null) {
response.append(line);
response.append('\r');
}
rd.close();
return response.toString();
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (connection != null) {
connection.disconnect();
}
}
Code example found here

How get response status

All good day!
Example code:
try {
URL object = new URL(url);
HttpURLConnection con = (HttpURLConnection) object.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestProperty("Content-Type", "application/json; charset=utf-8");
con.setRequestProperty("Accept", "application/json; charset=utf-8");
con.setRequestMethod("POST");
OutputStreamWriter wr= new OutputStreamWriter(con.getOutputStream());
wr.write(json);
wr.flush();
InputStream inputStream = con.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
while ((line=reader.readLine()) != null) {
response += "\n" + line;
}
How to get the status of a response?
Please, help!

con.getResponseCode();` // get status

How to Decode a xml Sent over Url in java

I am firing an online xml in java to the method below:
public String WriteToServer(String xml) {
StringBuilder answer = new StringBuilder();
try {
String myurl="example.com";
URL url = new URL(myurl);
URLConnection conn = url.openConnection(Proxy.NO_PROXY);
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(xml);
writer.flush();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
answer.append(line);
}
writer.close();
reader.close();
} catch (Exception e) {
System.out.println(e);
}
return answer.toString();
}
My Problem is that the server receives an encoded xml so it can not understand and returns a 500 response to the client. How can I decode a xml to a plain text that the server can read?

Try below code just before creating OutputStreamWriter instance
String myurl="example.com";
URL url = new URL(myurl);
URLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Language", "en-US");
conn.setUseCaches (false);
conn.setDoInput(true);
conn.setDoOutput(true);

How to stream a JSON object to a HttpURLConnection POST request

I can not see what is wrong with this code:
JSONObject msg; //passed in as a parameter to this method
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setDoInput(true);
httpCon.setUseCaches(false);
httpCon.setRequestProperty( "Content-Type", "application/json" );
httpCon.setRequestProperty("Accept", "application/json");
httpCon.setRequestMethod("POST");
OutputStream os = httpCon.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
msg.write(osw);
osw.flush();
osw.close();
os.close(); //probably overkill
On the server, I am getting no post content at all, a zero length string.

Try
...
httpCon.setRequestMethod("POST");
httpCon.connect(); // Note the connect() here
...
OutputStream os = httpCon.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
...
osw.write(msg.toString());
osw.flush();
osw.close();
to send data.
to retrieve data try:
BufferedReader br = new BufferedReader(new InputStreamReader( httpCon.getInputStream(),"utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
System.out.println(""+sb.toString());

public String sendHTTPData(String urlpath, JSONObject json) {
HttpURLConnection connection = null;
try {
URL url=new URL(urlpath);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Accept", "application/json");
OutputStreamWriter streamWriter = new OutputStreamWriter(connection.getOutputStream());
streamWriter.write(json.toString());
streamWriter.flush();
StringBuilder stringBuilder = new StringBuilder();
if (connection.getResponseCode() == HttpURLConnection.HTTP_OK){
InputStreamReader streamReader = new InputStreamReader(connection.getInputStream());
BufferedReader bufferedReader = new BufferedReader(streamReader);
String response = null;
while ((response = bufferedReader.readLine()) != null) {
stringBuilder.append(response + "\n");
}
bufferedReader.close();
Log.d("test", stringBuilder.toString());
return stringBuilder.toString();
} else {
Log.e("test", connection.getResponseMessage());
return null;
}
} catch (Exception exception){
Log.e("test", exception.toString());
return null;
} finally {
if (connection != null){
connection.disconnect();
}
}
}`
call this methopd in doitbackground in asynctask

HttpURLConnection is cumbersome to use. With DavidWebb, a tiny wrapper around HttpURLConnection, you can write it like this:
JSONObject msg; //passed in as a parameter to this method
Webb webb = Webb.create();
JSONObject result = webb.post("http://my-url/path/to/res")
.useCaches(false)
.body(msg)
.ensureSuccess()
.asJsonObject()
.getBody();
If you don't like it, there is a list of alternative libraries on the link provided.
Why should we all write the same boilerplate code every day? BTW the code above is more readable and less error-prone. HttpURLConnection has an awful interface. This has to be wrapped!

Follow this example:
public static PricesResponse getResponse(EventRequestRaw request) {
// String urlParameters = "param1=a&param2=b&param3=c";
String urlParameters = Piping.serialize(request);
HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters);
PricesResponse response = null;
try {
// POST
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
// RESPONSE
BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8));
String json = Buffering.getString(reader);
response = (PricesResponse) Piping.deserialize(json, PricesResponse.class);
writer.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
conn.disconnect();
System.out.println("PricesClient: " + response.toString());
return response;
}
public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) {
return RestClient.getConnection(endPoint, "POST", urlParameters);
}
public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) {
System.out.println("ENDPOINT " + endPoint + " METHOD " + method);
HttpURLConnection conn = null;
try {
URL url = new URL(endPoint);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(method);
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/plain");
} catch (IOException e) {
e.printStackTrace();
}
return conn;
}

this without json String post data to server
class PostLogin extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... params) {
String response = null;
Uri.Builder builder= new Uri.Builder().appendQueryParameter("username","amit").appendQueryParameter("password", "amit");
String parm=builder.build().getEncodedQuery();
try
{
response = postData("your url here/",parm);
}catch (Exception e)
{
e.printStackTrace();
}
Log.d("test", "response string is:" + response);
return response;
}
}
private String postData(String path, String param)throws IOException {
StringBuffer response = null;
URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
// connection.setRequestProperty("Content-Type", "application/json");
// connection.setRequestProperty("Accept", "application/json");
OutputStream out = connection.getOutputStream();
out.write(param.getBytes());
out.flush();
out.close();
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
response = new StringBuffer();
while ((line = br.readLine()) != null) {
response.append(line);
}
br.close();
}
return response.toString();
}