I am using below code to send GET api request. The url below has a parameter e.g. String url = "https://my/api"+variable+"test". I am using for loop to iterate through the list of variables (which are more than 2000) and create url to send get API request using below code. I want to send multiple api requests in parallel to reduce the overall time. Please suggest what is the best way for that.
URL _url = new URL(url);
HttpURLConnection con = (HttpURLConnection) _url.openConnection();
Authenticator authenticator = new Authenticator() {
public PasswordAuthentication getPasswordAuthentication() {
return (new PasswordAuthentication(user,
password.toCharArray()));
}
};
Authenticator.setDefault(authenticator);
con.setRequestMethod("GET");
con.setRequestProperty("Accept", "application/json");
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
JSONObject Obj = new JSONObject(response.toString());
Suggest you check out the Java ExecutorService:
https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html
You can create async tasks and execute them on a thread pool, then wait for the results to complete. There are several good tutorials for this.
For instance:
https://www.baeldung.com/java-executor-service-tutorial
Related
I want to test my application if it can handle many Request parallel. To test this i simply initialised the Request about 50 times. Each Request in a own Thread.
The run() Method looks sth. like this with a bit more Stuff.
public void run(){
URL getUrl = new URL(url);
HttpURLConnection con = (HttpURLConnection) getUrl.openConnection();
con.setRequestMethod("GET");
BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
while ((data = br.readLine()) != null) {
sb.append(data);
}
br.close();
}
The stragne thing is that with more Request the time per Request is reducing significant to about 50%. Why is this happening? Does the Java HTTP Connection cache the Request?
I'm trying to send a get request in order to get a website content.
When I'm using Postman it takes about 70-100 ms, but when I use the following code:
String getUrl = "someUrl";
URL obj = new URL(getUrl);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
// optional default is GET
con.setRequestMethod("GET");
//add request header
con.setRequestProperty("User-Agent", "Mozilla/5.0");
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null)
{
response.append(inputLine);
}
in.close();
response.toString();
it takes about 3-4 seconds.
Any idea how to get my code work as fast as Postman?
Thanks.
Try to find a workaround for the while loop. Maybe that is your bottleneck. What are you even getting from your URL? Json object or something else?
Try http-request built on apache http api.
HttpRequest<String> httpRequest = HttpRequestBuilder.createGet(someUri, String.class)
.responseDeserializer(ResponseDeserializer.ignorableDeserializer())
.addDefaultHeader("User-Agent", "Mozilla/5.0")
.build();
public void send(){
String response = httpRequest.execute().get();
}
I higly recomend read documentation before use.
I am trying to grab a site's source code using this code
private static String getUrlSource(String url) throws IOException {
URL url = new URL(url);
URLConnection urlConn = url.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(
urlConn.getInputStream(), "UTF-8"));
String inputLine;
StringBuilder a = new StringBuilder();
while ((inputLine = in.readLine()) != null)
a.append(inputLine);
in.close();
return a.toString();
}
When I do grab the site code this way I get an error about needing to allow cookies. Is there anyway to allow cookies in a java application just so I can grab some source code? I do have the cookie my browser uses to log me in if that helps.
Thanks
John
This way you would have to deal with raw request data, Go with apache http client that gives you abstraction and some methods to allow to set headers in request
I have a data access object which calls a web service. In my browser I can hit the web service using a url and it is successful.
http://mycompany:9080/ReportingManager/service/repManHealth/importHistoryTrafficLightStatus.json
But when try to execute the code below in my data access object I get a 405 error saying method not allowed.
String requestURI = "http://mycompany:9080/ReportingManager/service/repManHealth/importHistoryTrafficLightStatus.json";
URL url = new URL(requestURI);
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setRequestMethod("GET");
httpCon.setRequestProperty("Accept", "application/json");
OutputStreamWriter out = new OutputStreamWriter(
httpCon.getOutputStream());
int responseCode = httpCon.getResponseCode();
String responseMessage = httpCon.getResponseMessage();
BufferedReader rd = new BufferedReader(new InputStreamReader(httpCon.getInputStream()));
StringBuffer sb = new StringBuffer();
String line = null;
while ((line = rd.readLine()) != null) {
sb.append(line);
}
rd.close();
String jsonResponse = sb.toString();
out.close();
httpCon.disconnect();
Can someone help me with what might be wrong here?
Also maybe there is a better way to execute a web service to an external application and read the response using struts? Or do people think this method is okay?
thanks
If u are using GET method. Try the below code.
string url = String.Format("http://somedomain.com/samplerequest?greeting={0}",param);
WebClient serviceRequest = new WebClient();
serviceRequest.Headers[HttpRequestHeader.ContentType] = "application/json";
string response = serviceRequest.DownloadString(new Uri(url));
Thanks for your ideas however non of them were quite right. I fixed the 405 using the code below...
String requestURI = "http://myserver:9080/ReportingManager/service/repManHealth/importHistoryTrafficLightStatus.json";
URL url = new URL(requestURI);
URLConnection conn = url.openConnection();
InputStream in = conn.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(in));
StringBuffer sb = new StringBuffer();
String line = null;
while ((line = rd.readLine()) != null) {
sb.append(line);
}
rd.close();
By calling httpCon.getOutputStream()); you're not sending a HTTP GET anymore, but a HTTP POST.
Note: This is under the assumption you end up getting the implementation provided by Sun. Which will change GET to POST for backwards compatibility.
I am trying to send an HTTP POST Request to a remote server using an instance of the HttpURLConnection class. Although, I am able to get a response code and a response message, when I try to write the input stream into a StringBuffer, I am not able to actually read any lines.
When I analyzed the packets sent from WireShark, I noticed that a full response was being sent from the remote server. My only guess as to why I am not able to see it in the Java program is because the time in which I try to read from the InputStream is too late.
So, how do I read the immediate, full response from the remote server using my HttpURLConnection object? Below is the code that I am using:
HttpURLConnection conn = null;
String urlStr = "...";
URL url = null;
try
{
url = new URL(urlStr);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
...
BufferedReader rd = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line;
while ((line = rd.readLine()) != null)
{
sb.append(line);
}
rd.close();
...
}...
Okay, never mind. It turns out that what I was looking for was in the HTTP Respone's header. So, I got what I needed by looking through its headers. ::Face Palm::