STEP: Create dynamic web project with JAX-RS support STEP: Create JAX-RS web service with one GET method with @QueryParam parameters: HelloWorld.java @GET() public String method(@QueryParam( "param1" ) String param1, @QueryParam( "param2" ) String param2, @QueryParam( "param3" ) String param3, @QueryParam( "param4" ) String param4) { return param1 + ", " + param2 + ", " + param3 + ", " + param4; } STEP: Click on context menu (Run As -> Run on Server) of this GET method in JAX-RS explorer, Web Service Tester view should be visible now STEP: Click Invoke Button. In dialog set all query parameters. STEP: Fix the URL to contain two slashes after http (known issue: https://issues.jboss.org/browse/JBIDE-11728 ) STEP: Press Invoke button again ASSERT: Response message is: param1, param2, param3, param4 FAIL: Response message is: param1, param2, param3, param4? STEP: Reorder the return message in GET method so last query parameter is not the last in response message, for example: HelloWorld.java @GET() public String method(@QueryParam( "param1" ) String param1, @QueryParam( "param2" ) String param2, @QueryParam( "param3" ) String param3, @QueryParam( "param4" ) String param4) { return param1 + ", " + param2 + ", " + param4 + ", " + param3; } STEP: Redeploy the project STEP: Press Invoke button in Web Service Tester (choose the same URL as before) ASSERT: Response message is: param1, param2, param4, param3 FAIL: Response message is: param1, param2, param4?, param3