post request with spring mvc(RestTemplate) brings an unkown host error . But yet posting the same request works fine with postman all the time - spring

Question

I am using Spring MVC RestTemplate. Whenever i send a post request to a service end point(using my spring mc app) i get an error that the destination host is unknown. But if i post the same request several times, by refreshing the browser repeatedly(which is not desirable) the request gets sent and the response comes . And when i post the same request via postman no problem at all, the request is succesifully posted and i get the response back all the time. Thanks in advance for the help.
this is my post request code
//creating a RestTemplate instance with appropriate message converters
private RestTemplate createXMLRestTemplate() throws Exception {
ArrayList<HttpMessageConverter<?>> messageConverters = new
ArrayList<HttpMessageConverter<?>>();
messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
messageConverters.add(new MappingJackson2HttpMessageConverter());
restTemplate = new RestTemplate();
restTemplate.setMessageConverters(messageConverters);
return restTemplate;
}
#GET
#Path ("/paymentservicerequest")
#Produces(MediaType.APPLICATION_XML)
public APIResponse PaymentServiceAPIRequest() throws Exception
{
RestTemplate restTemplate =this.createXMLRestTemplate();
restTemplate.getInterceptors().add(new ClientHttpRequestInterceptor() {
#Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
request.getHeaders().add("Content-Type", MediaType.APPLICATION_XML.toString());
return execution.execute(request, body);
}
});
Date current= new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
String currentdateString =dateFormat.format(current);
Date currentdate;
try {
currentdate = dateFormat.parse(currentdateString);
} catch (ParseException e) {
currentdate=new Date();
e.printStackTrace();
}
//Initializing the PaymentServiceTransaction jaxb pojo through its class constructor
PaymentServiceTransaction=new PaymentServiceTransaction(new BigDecimal(300.00), "TZS","E4C5E0A","https://www.example.com/rest/payresponse/itemtype/itemid",
"https://www.example.com/rest/payresponseback/itemtype/itemid",true,180, "https://www.example.com/rest/payresponsedecline/itemtype/itemid");
PaymentServiceAPI=new PaymentServiceAPI("XRSXSX27B","createToken",PaymentServiceTransaction,PaymentServiceServices);
HttpEntity<PaymentServiceAPI> request = new HttpEntity<PaymentServiceAPI>(PaymentServiceAPI);
//A JAXB POJO APIResponse as a returned response
APIResponse response=null;
try {
response= restTemplate.postForObject("https://example.sandbox.domain.online/API/version/",request,APIResponse.class);
} catch (HttpStatusCodeException exception) {
int statusCode = exception.getStatusCode().value();
System.out.println("ERROR CODE:"+statusCode+":"+exception);
}
System.out.println(response.toString());
return response;
}
the error that i get is:
java.net.UnknownHostException: example.sandbox.domain.online/API/version/
java.net.AbstractPlainSocketImpl.connect(Unknown Source)
java.net.PlainSocketImpl.connect(Unknown Source)
java.net.SocksSocketImpl.connect(Unknown Source)
java.net.Socket.connect(Unknown Source)
sun.security.ssl.SSLSocketImpl.connect(Unknown Source)
sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source)
sun.net.NetworkClient.doConnect(Unknown Source)
sun.net.www.http.HttpClient.openServer(Unknown Source)
sun.net.www.http.HttpClient.openServer(Unknown Source)
sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
sun.net.www.protocol.http.HttpURLConnection.plainConnect0(Unknown Source)
sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:78)
org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48)
org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53)
org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:99)
com.musicstore.onlinemusicshop.controller.TransactionalRestController$2.intercept(TransactionalRestController.java:233)
org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:86)
org.springframework.http.client.InterceptingClientHttpRequest.executeInternal(InterceptingClientHttpRequest.java:70)
org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48)
org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53)
org.springframework.web.client.RestTemplate.execute(RestTemplate.java:628)
org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:398)
com.musicstore.onlinemusicshop.controller.TransactionalRestController.directPayAPI3GRequest(TransactionalRestController.java:305)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
com.sun.jersey.server.impl.uri.rules.SubLocatorRule.invokeSubLocator(SubLocatorRule.java:171)
com.sun.jersey.server.impl.uri.rules.SubLocatorRule.accept(SubLocatorRule.java:107)
com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:158)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)