Java Httpclient HttpRequestRetryHandler doesn't work. How to implement retrys?
I am trying to implement request retries after response isn't received. I was reading about it in the Httpclient tutorial. the HttpRequestRetryHandler gets invoked only once and then it throw exception . what do I do wrong here?
updated
I added oneif
condition in the exception handling for SocketTimeoutException.
but what to do from there? how can I retry?
private void setRetry(int executionCount)
{
myRetryHandler = new HttpRequestRetryHandler() {
public boolean retryRequest(IOException exception,int executionCount,HttpContext context) {
if (executionCount >= 4) {
// Do not retry if over max retry count
System.out.println("retry count");
return false;
}
if (exception instanceof NoHttpResponseException) {
System.out.println("NoHttpResponseException exception");// Retry if the server dropped connection on us
return true;
}
if (exception instanceof SSLHandshakeException) {
// Do not retry on SSL handshake exception
System.out.println("SSLHandshakeException exception");
return false;
}
if (exception instanceof java.net.SocketTimeoutException) {
// Do not retry on SSL handshake exception
System.out.println("java.net.SocketTimeoutException exception");
return false;
}
HttpRequest request = (HttpRequest) context.getAttribute( ExecutionContext.HTTP_REQUEST);
boolean idempotent = !(request instanceof HttpEntityEnclosingRequest);
if (idempotent) {
System.out.println("idempotent exception");
// Retry if the request is considered idempotent
return true;
}
return false;
}
};
}
public String postHttpReqest(int retries,
int socketTimeoutMillis,
int isSSL,
String target,
String url,
String base_url,
int port,
LinkedHashMap<String, String> lHashMapParams) throws Exception
{
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, 50000);
HttpConnectionParams.setSoTimeout(httpParams, socketTimeoutMillis);
defaulthttpclient = new DefaultHttpClient(httpParams);
setRetry(retries); // here i set the handler
defaulthttpclient.setHttpRequestRetryHandler(myRetryHandler);
String line = "";
List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();
for (String key : lHashMapParams.keySet()) {
String val = lHashMapParams.get(key);
params.add(new BasicNameValuePair(ke开发者_运维问答y,val));
}
UrlEncodedFormEntity query = new UrlEncodedFormEntity(params);
HttpPost httppost = new HttpPost(url+":"+Integer.toString(port)+"//"+base_url);
httppost.setEntity(query);
HttpResponse response_ = defaulthttpclient.execute(httppost);
HttpEntity entity = response_.getEntity();
if (entity != null) {
line = EntityUtils.toString(entity);
System.out.println(line);
}
return line;
}
In the server, I set break point so it will hold the connection and will not return response. The error I am getting in the Httpclient :
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:149)
at org.apache.http.impl.io.SocketInputBuffer.fillBuffer(SocketInputBuffer.java:110)
at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:260)
at org.apache.http.impl.conn.LoggingSessionInputBuffer.readLine(LoggingSessionInputBuffer.java:115)
at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:98)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:252)
at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:281)
at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:247)
at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:219)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:298)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:633)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:454)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:820)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:754)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:732)
at com.fts.lb.connector.ut.HttpClientImpl.postHttpReqest(HttpClientImpl.java:183)
Um .. your RetryHandler is specifically returning false for a SocketTimeoutException. So I would expect it to throw an Exception 100% of the time, which it is.
If you want the Request to be retried when the client times out before receiving a response, then you need to have your RetyrHandler return true for SocketTimeOutExceptions. You might also want to increase your SocketTimeOut before retrying.
Googlein a little bit I found this bug in the HttpClient 4.1 client (only on Windows).
For my problem I already use the latest 4.1.1, but maybe I have to implement the retryHandler.
I hope it will be helpful.
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