title: restTemplate java.lang.IllegalArgumentException: "None" does not contain '/'
body: <p>Ok first of all code (its mega simple):</p>
  
  <pre><code>@Controller
  @RequestMapping("/")
  
  public class HelloController {
  
  private final static Logger logger = Logger.getLogger(HelloController.class);
  @RequestMapping(method = RequestMethod.GET)
  public String printWelcome(ModelMap model) {
  
      logger.info("ELO ELO");
      model.addAttribute("message", "Hello world!");
  
      RestTemplate restTemplate = new RestTemplate();
  
      String url = "http://192.168.0.200:8000/GPIO/11/function/in";
      //String url = "http://192.168.0.200:8000/GPIO/11/function";
      //restTemplate.getForObject(url, String.class);
      String test = "";
  
      restTemplate.postForObject(url, null, String.class);
  
  
  
      logger.info(test);
      return "hello";
  }
  </code></pre>
  
  <p>Next example that I'm not a crazy man here is response from postman (chrome):</p>
  
  <p><img src="https://i.stack.imgur.com/GANxv.png" alt="enter image description here"></p>
  
  <p>And at the end full error log:</p>
  
  <blockquote>
    <p>type Exception report</p>
    
    <p>message Request processing failed; nested exception is
    java.lang.IllegalArgumentException: "None" does not contain '/'</p>
    
    <p>description The server encountered an internal error that prevented it
    from fulfilling this request.</p>
    
    <p>exception</p>
    
    <p>org.springframework.web.util.NestedServletException: Request
    processing failed; nested exception is
    java.lang.IllegalArgumentException: "None" does not contain '/'
      org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:927)
      org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
      javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
      org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
      javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
      org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    root cause</p>
    
    <p>java.lang.IllegalArgumentException: "None" does not contain '/'
      org.springframework.http.MediaType.parseMediaType(MediaType.java:697)
      org.springframework.http.HttpHeaders.getContentType(HttpHeaders.java:305)
      org.springframework.web.client.HttpMessageConverterExtractor.getContentType(HttpMessageConverterExtractor.java:113)
      org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:84)
      org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:492)
      org.springframework.web.client.RestTemplate.execute(RestTemplate.java:447)
      org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:295)
      pl.piquarium.mvc.HelloController.printWelcome(HelloController.java:35)
      sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      java.lang.reflect.Method.invoke(Method.java:606)
      org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
      org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:439)
      org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:427)
      org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
      org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
      org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
      org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
      javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
      org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
      javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
      org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    note The full stack trace of the root cause is available in the Apache
    Tomcat/8.0.3 logs.</p>
  </blockquote>
  
  <p>Request headers:</p>
  
  <pre><code>Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
  Accept-Encoding:gzip,deflate,sdch
  Accept-Language:pl-PL,pl;q=0.8,en-US;q=0.6,en;q=0.4
  Cache-Control:max-age=0
  Connection:keep-alive
  Cookie:__utma=212787668.2094541430.1400264829.1400264829.1400268775.2; __utmz=212787668.1400264829.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)
  Host:192.168.0.200:8000
  User-Agent:Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.137 Safari/537.36
  </code></pre>
  
  <p>Response Headers:</p>
  
  <pre><code>Cache-Control:no-cache
  Content-Length:2
  Content-Type:None
  Date:Fri, 16 May 2014 22:37:16 GMT
  Server:WebIOPi/0.7.0/Python3.2
  </code></pre>