A JSON object in a POST request for webserver with JERSEY

问题

I know this question is already posted here , but I am stuck at one point and I am not getting exact solution so posting it again here.

I have written a simple RESTFul web service with Jersey . In a POST method , I am passing JSON object in request.

I am using annotated @XmlRootElement Class, and the same is used for POST method.

The code looks like as follows - My POJO class

  @XmlRootElement
public class WelcomeForm {
    public String title;

    public WelcomeForm(){
        title = "";
    }

    public WelcomeForm(String inTitle){
        title = inTitle;
    }
}

Web service is as follows

    @Path("/welcome")
public class WelcomeImpl {

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public WelcomeForm welcome(WelcomeForm welcomeFormObject) {
        WelcomeForm form = new WelcomeForm();
        form.title = " Connected ... ";
        System.out.println("welcomeFormObject *** "+welcomeFormObject.title);
        return form;
    }
}

When I tried to run a simple html code by passing a json object in request am getting an error as

/* in browser I get error as follows */
        XMLHttpRequest cannot load http://localhost:8081/ws/welcome. Origin http://localhost:8080 is not allowed by Access-Control-Allow-Origin. 

    /* in eclipse I get error as follows */
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String
    Apr 27, 2013 5:59:51 AM com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
    INFO: Couldn't find grammar element for class java.lang.String

Then I added Custom Filer Class, to resolve Access-Control-Origin not allowed error

public class CustomResponseFilters implements ContainerResponseFilter {
public ContainerResponse filter(ContainerRequest request, ContainerResponse response) {
    // After request processed
    response.getHttpHeaders().add("Access-Control-Allow-Origin", "http://MyIPAddress:8080");
    response.getHttpHeaders().add("Access-Control-Allow-Methods", "PUT, GET, POST, DELETE, OPTIONS");
    response.getHttpHeaders().add("Access-Control-Allow-Headers", "Content-Type");
    return response;
}

}

But its of no useful , I got same error again.

Here is my html code

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
        <title></title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" type="text/javascript"></script>
        <script type="text/javascript">
            function CallService() {

                var obj = {};
                obj.title ="Hello!!!";
                console.log(obj.title);
                $.ajax({
                       type: "POST",
                       url: "http://MyIPAddress:8081/ws/welcome",
                       data: JSON.stringify(obj),
                       contentType: "application/json; charset=utf-8",
                       dataType: "application/json",
                       success: function (response) {
                       console.log(" **** success ** "+response);
                       }
                       });
            }

            </script>
    </head>
    <body>
        <form id="form1" runat="server">
            <div>
                <input type=button onclick="CallService()" name="Button1" value="Button1" />
            </div>
        </form>
    </body>
</html>

So what is wrong in this ? Am I missing something ? And when we do get Access-Control-Allow-Origin error ? And I have done changes in web.xml file to mention the filter class

<init-param>
   <param-name>com.sun.jersey.spi.container.ContainerResponseFilters</param-name>
   <param-value>com.ws.form.CustomResponseFilters</param-value>
 </init-param>

Am I missing Anything else ??

回答1:

The error (Its not actually an error) com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes INFO: Couldn't find grammar element for class java.lang.String

is unrelated to the cross domain problem.

I'm not sure why its happening I have read it is something to do with using a default constructor along with @XmlRootElement. Anyways 2 options to get rid of it either put

@OPTIONS
public Response myResource() {

    return Response.ok().build();
}

or disable wadl in the web.xml

<init-param>
    <param-name>com.sun.jersey.config.feature.DisableWADL</param-name>
    <param-value>true</param-value>
</init-param>

来源：https://stackoverflow.com/questions/16247110/a-json-object-in-a-post-request-for-webserver-with-jersey

标签

web-services

jersey