title: Groovy httpbuilder ResponseParseException Invalid JSON string
body: <p>i trying to build a api consumer in groovy using httpBuilder. My backend api returns json output with content type application/json. But when i set  content type in httpbuilder object to JSON it throws Invalid Json String error.</p>
  
  <pre><code>static def webServiceRequest(String baseUrl, String path, def data,method=Method.GET,contentType=ContentType.JSON){
          try {
              def ret = null
              def http = new HTTPBuilder(baseUrl)
              http.request(method, contentType) {
                  uri.path = path
                  if(method==Method.GET)
                      uri.query = data
                  else
                      body = data
                  headers.'User-Agent' = 'Mozilla/5.0 Ubuntu/8.10 Firefox/3.0.4'
  
  
                  response.success = { resp, json -&gt;
                      println "response status: ${resp.statusLine}"
                      ret = json
                      println '--------------------'
                  }
              }
              return ret
  
          } catch (Exception ex) {
              ex.printStackTrace();
              return null;
          }
      }
  </code></pre>
  
  <p>the above function calls the api.</p>
  
  <pre><code>def response = webServiceRequest(grailsApplication.config.getProperty ("site.triggerReasons"),'/do/dataquality/FOSAutomation/doAction/',data,Method.GET,ContentType.JSON)
  </code></pre>
  
  <p>actual output on browser with content type application/json</p>
  
  <pre><code>{ "status" : "OK", "data" : { "totalTasks" : 0 }, "error" : "" }
  </code></pre>
  
  <p>exception stacktrace:</p>
  
  <pre><code>groovyx.net.http.ResponseParseException: OK
      at groovyx.net.http.HTTPBuilder.doRequest(HTTPBuilder.java:467)
      at groovyx.net.http.HTTPBuilder.doRequest(HTTPBuilder.java:417)
      at groovyx.net.http.HTTPBuilder.request(HTTPBuilder.java:366)
      at groovyx.net.http.HTTPBuilder$request.call(Unknown Source)
      at com.nnacres.ApiConsumer.webServiceRequest(ApiConsumer.groovy:29)
      at com.nnacres.ApiConsumer$webServiceRequest.call(Unknown Source)
      at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
      at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
      at com.nnacres.taskAllocator.AllocatorService$$EQ8pAKDw.clearTasksService(AllocatorService.groovy:114)
      at com.nnacres.taskAllocator.AllocatorService$$DQ8pAKDw.clearTasksService(Unknown Source)
      at com.nnacres.taskAllocator.AllocatorService.clearTasksService(AllocatorService.groovy)
      at com.nnacres.taskAllocator.AllocatorService$clearTasksService$0.call(Unknown Source)
      at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
      at com.nnacres.taskAllocator.AllocatorService$clearTasksService$0.call(Unknown Source)
      at com.nnacres.taskAllocator.RiAllocatorController.clearTasks(RiAllocatorController.groovy:97)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:497)
      at org.springsource.loaded.ri.OriginalClassInvoker.invoke(OriginalClassInvoker.java:50)
      at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1461)
      at org.grails.core.DefaultGrailsControllerClass$ReflectionInvoker.invoke(DefaultGrailsControllerClass.java:210)
      at org.grails.core.DefaultGrailsControllerClass.invoke(DefaultGrailsControllerClass.java:187)
      at org.grails.web.mapping.mvc.UrlMappingsInfoHandlerAdapter.handle(UrlMappingsInfoHandlerAdapter.groovy:90)
      at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:961)
      at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:895)
      at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
      at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
      at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
  
      at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
  
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(Endpo
  intWebMvcAutoConfiguration.java:281)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:115)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:75)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.grails.web.filters.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:67)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:103)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
      at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
      at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
      at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
      at java.lang.Thread.run(Thread.java:745)
  Caused by: net.sf.json.JSONException: Invalid JSON String
      at net.sf.json.JSONSerializer.toJSON(JSONSerializer.java:143)
      at net.sf.json.JSONSerializer.toJSON(JSONSerializer.java:103)
      at net.sf.json.groovy.JsonSlurper.parseText(JsonSlurper.java:80)
      at groovyx.net.http.ParserRegistry.parseJSON(ParserRegistry.java:248)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:497)
      at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1432)
      at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
      at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
      at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1215)
      at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1082)
      at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
      at groovy.lang.Closure.call(Closure.java:414)
      at groovy.lang.Closure.call(Closure.java:430)
      at groovyx.net.http.HTTPBuilder.parseResponse(HTTPBuilder.java:518)
      at groovyx.net.http.HTTPBuilder.doRequest(HTTPBuilder.java:460)
      ... 74 more
  </code></pre>
  
  <p>the issue is coming when the service i'm hitting is in PHP.
  In PHP service i'm setting content type application/json using <strong>header('Content-Type: application/json');</strong>. and then just echo the result in a controller.</p>