I would like to filter a Post request in Filter (prior it getting to the Resource).
To filter the request I want to retrieve a token from the bode request and do some testing on it.
Current Resource:
#Post
public JsonRepresentation init(JsonRepresentation jRep) {
String token = jRep.getJsonObject().getString("token");
.
.
.
}
Current Filter:
#Override
protected int beforeHandle(Request request, Response response) {
int result = STOP;
String token = (String) Request.getCurrent().getAttributes().get("token");
.
.
.
}
These code does not retrieve the token.
My question is how can I retrieve a body request?
You can directly get the payload text of the request from its associated entity object, as described below:
Representation repr = request.getEntity();
String content = repr.getText();
Hope it helps you,
Thierry
you can try something like this to retreive the body :
public static String getBody(HttpServletRequest request) throws IOException {
String body = null;
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
InputStream inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
throw ex;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
throw ex;
}
}
}
body = stringBuilder.toString();
return body;
}
As it is dangerous to store request entities directly into memory (imagine if a client send a tera-bytes representation), the framework does not persist representations into memory by default, they can only be read once (from the socket).
I guess the answers to your issue may be read from here: Restlet reuse InputStream
Related
Is there any way to read inputStream of a request without losing the data in it.
I am trying to take a raw copy of my request into string before processing it. But once I read the inputstream from request, the inputstream is changing to null so, I can't get Parameter from my request later. I tried using CustomHttpServletRequestWrapper but it did not work. Below is the snippet of my code.
The InboundHandler is my handler class which has the processRequest(HttpServletRequest request, HttpServletResponse response) method that is invoked from my servlet class.
public class InboundHandler {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
CustomHttpServletRequestWrapper requestWrapper = new CustomHttpServletRequestWrapper(request);
String body = getRequestBody(requestWrapper.getInputStream());
String from = request.getParameter("from"); //which I'm getting null here
// I also tried using
// String from = requestWrapper.getParameter("from"); // Even this did not work
} catch (Exception e) {
e.printStackTrace();
}
}
private String getRequestBody(InputStream inputStream) {
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) != -1) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
}
} catch (IOException ex) {
ex.printStackTrace();
//throw new AuthenticationException("Error reading the request payload", ex);
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException iox) {
// ignore
}
}
}
return stringBuilder.toString();
}
public class CustomHttpServletRequestWrapper extends HttpServletRequestWrapper {
private final String body;
public CustomHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
InputStream inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
ex.printStackTrace();
//log.error("Error reading the request body...");
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
ex.printStackTrace();
//log("Error closing bufferedReader...");
}
}
}
body = stringBuilder.toString();
}
#Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
ServletInputStream inputStream = new ServletInputStream() {
public int read() throws IOException {
return byteArrayInputStream.read();
}
};
return inputStream;
}
}
}
Q: Is there any way to read inputStream of a request without losing the data in it?
A: Yes - simply "save" what you "read"!
As Perdomoff correctly said, "Requests aren't meant to be reused". You can't put the water back in the hose once you've watered your garden :)
You can save the data. Perdomoff suggested using a session variable.
Another alternative might be to use a Servlet Filter. Here is a good tutorial:
http://www.journaldev.com/1933/java-servlet-filter-example-tutorial
In Java, this code throws an exception when the HTTP result is 404 range:
URL url = new URL("http://stackoverflow.com/asdf404notfound");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.getInputStream(); // throws!
In my case, I happen to know that the content is 404, but I'd still like to read the body of the response anyway.
(In my actual case the response code is 403, but the body of the response explains the reason for rejection, and I'd like to display that to the user.)
How can I access the response body?
Here is the bug report (close, will not fix, not a bug).
Their advice there is to code like this:
HttpURLConnection httpConn = (HttpURLConnection)_urlConnection;
InputStream _is;
if (httpConn.getResponseCode() < HttpURLConnection.HTTP_BAD_REQUEST) {
_is = httpConn.getInputStream();
} else {
/* error from server */
_is = httpConn.getErrorStream();
}
It's the same problem I was having:
HttpUrlConnection returns FileNotFoundException if you try to read the getInputStream() from the connection.
You should instead use getErrorStream() when the status code is higher than 400.
More than this, please be careful since it's not only 200 to be the success status code, even 201, 204, etc. are often used as success statuses.
Here is an example of how I went to manage it
... connection code code code ...
// Get the response code
int statusCode = connection.getResponseCode();
InputStream is = null;
if (statusCode >= 200 && statusCode < 400) {
// Create an InputStream in order to extract the response object
is = connection.getInputStream();
}
else {
is = connection.getErrorStream();
}
... callback/response to your handler....
In this way, you'll be able to get the needed response in both success and error cases.
Hope this helps!
In .Net you have the Response property of the WebException that gives access to the stream ON an exception. So i guess this is a good way for Java,...
private InputStream dispatch(HttpURLConnection http) throws Exception {
try {
return http.getInputStream();
} catch(Exception ex) {
return http.getErrorStream();
}
}
Or an implementation i used. (Might need changes for encoding or other things. Works in current environment.)
private String dispatch(HttpURLConnection http) throws Exception {
try {
return readStream(http.getInputStream());
} catch(Exception ex) {
readAndThrowError(http);
return null; // <- never gets here, previous statement throws an error
}
}
private void readAndThrowError(HttpURLConnection http) throws Exception {
if (http.getContentLengthLong() > 0 && http.getContentType().contains("application/json")) {
String json = this.readStream(http.getErrorStream());
Object oson = this.mapper.readValue(json, Object.class);
json = this.mapper.writer().withDefaultPrettyPrinter().writeValueAsString(oson);
throw new IllegalStateException(http.getResponseCode() + " " + http.getResponseMessage() + "\n" + json);
} else {
throw new IllegalStateException(http.getResponseCode() + " " + http.getResponseMessage());
}
}
private String readStream(InputStream stream) throws Exception {
StringBuilder builder = new StringBuilder();
try (BufferedReader in = new BufferedReader(new InputStreamReader(stream))) {
String line;
while ((line = in.readLine()) != null) {
builder.append(line); // + "\r\n"(no need, json has no line breaks!)
}
in.close();
}
System.out.println("JSON: " + builder.toString());
return builder.toString();
}
I know that this doesn't answer the question directly, but instead of using the HTTP connection library provided by Sun, you might want to take a look at Commons HttpClient, which (in my opinion) has a far easier API to work with.
First check the response code and then use HttpURLConnection.getErrorStream()
InputStream is = null;
if (httpConn.getResponseCode() !=200) {
is = httpConn.getErrorStream();
} else {
/* error from server */
is = httpConn.getInputStream();
}
My running code.
HttpURLConnection httpConn = (HttpURLConnection) urlConn;
if (httpConn.getResponseCode() < HttpURLConnection.HTTP_BAD_REQUEST) {
in = new InputStreamReader(urlConn.getInputStream());
BufferedReader bufferedReader = new BufferedReader(in);
if (bufferedReader != null) {
int cp;
while ((cp = bufferedReader.read()) != -1) {
sb.append((char) cp);
}
bufferedReader.close();
}
in.close();
} else {
/* error from server */
in = new InputStreamReader(httpConn.getErrorStream());
BufferedReader bufferedReader = new BufferedReader(in);
if (bufferedReader != null) {
int cp;
while ((cp = bufferedReader.read()) != -1) {
sb.append((char) cp);
}
bufferedReader.close();
}
in.close();
}
System.out.println("sb="+sb);
How to read 404 response body in java:
Use Apache library - https://hc.apache.org/httpcomponents-client-4.5.x/httpclient/apidocs/
or
Java 11 - https://docs.oracle.com/en/java/javase/11/docs/api/java.net.http/java/net/http/HttpClient.html
Snippet given below uses Apache:
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.util.EntityUtils;
CloseableHttpClient client = HttpClients.createDefault();
CloseableHttpResponse resp = client.execute(new HttpGet(domainName + "/blablablabla.html"));
String response = EntityUtils.toString(resp.getEntity());
I'm writing a Servlet in Java, that basically, gets a request with a XML in the Requests body, and then changes a few things in the XML and redirect/foreword the request with The new XML to a different Servlet that's on the same server, but its on a different web app.
I'm using doPost.
How do i do that? can i find code example any where?
Plus, whats the correct method to use:?
request.getRequestDispatcher().include /request.getRequestDispatcher().foreword / response.sendRedirect() or do i need to use the: HttpServletRequestWrapper?
this is what i have so far:
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String body = getBody(request);
MapXml mapXml = new MapXml(body, "C:\\Projects\\XmlMapper\\output.xml","C:\\Projects\\XmlMapper\\output\\");
String outputXml = mapXml.getOutputXml();
}
public static String getBody(HttpServletRequest request) throws IOException {
String body = null;
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
InputStream inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
throw ex;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
throw ex;
}
}
}
body = stringBuilder.toString();
return body;
}
And i have no idea how to continue on from here. I'm new to the servlet world..
Thanks!!!
Cheers:)
I am making a little program thath will read data from website. String in the html file is already managed every info is divided with ; . Now i should read complete line here is example of this line:
14:47;24.02.12;18.7°C;18.7°C;285;0.5m/s; 6:48;17:37; Warm ;36;1.8;0.0;
So first how should i read them with HTTP Get or is there anything other? And then i would like to save each info, they are seperated with ; into a variable. And how should i cut each info from this line.
You definitely need to do some homework, but this methods will help you:
public static String getContentFromUrl(String url) throws ClientProtocolException, IOException {
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
HttpResponse response;
response = httpClient.execute(httpGet);
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream inStream = entity.getContent();
String result = HttpService.convertStreamToString(inStream);
inStream.close();
return result;
}
return null;
}
private static String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
This allows you to get data from a URL. Then lookup String.split to chop your string into usable entities.
Hope this helps!
Use GET request to fetch the data from the website
Separate the string-data from the HTML-markup
Parse the string into multiple strings or a list of strings, using ';' as the delimiter.
Android Java SDK String reference
What is the general approach to retrieve binary data that is posted to a Java Servlet? A byte[] is being posted to this servlet and I think I have to somehow parse the HttpServletRequest.getInputStream() and pull out the byte[] contents. Any ideas on how to change the below code to accomplish this?
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
InputStream inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(
inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
throw ex;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
throw ex;
}
}
}
String body = stringBuilder.toString();
System.out.println(body);
}
Don't wrap your inputstream in any "Reader"s, as they convert from bytes to characters, and you want the bytes.
yes. ditch all the Readers and use the InputStream you were handed on the 3rd line. if you don't understand the relationship between byte[] and InputStream, i would suggest reading the API docs and some good java tutorials.