Question

I have a REST Server in Java JAX-RS and an HTML page.

I want to send a JSON array, a username, and an accountID from the HTML page through an xmlhttp POST request by making all of them a single big String so I can use the xmthttp.send() method.

The HTML sending code is:

function sendData() {   
    var req = createRequest();
    var postUrl = "rest/hello/treeData";

    var dsdata = $("#treeview").data("kendoTreeView").dataSource.data();
    var accID = "onthespot";
    var username = "alex";

    req.open("post", postUrl, true);
    req.setRequestHeader("Content-type","text/plain");

    req.send("data=" + JSON.stringify(dsdata) + "&username=" + username + "&accID=" + accID);

    req.onreadystatechange = function() {
        if (req.readyState != 4) {
            return;
        }
        if (req.status != 200) {
            alert("Error: " + req.status);
            return;
        }
        alert("Sent Data Status: " + req.responseText);
    }
}

And the Server JAX-RS code is:

@Path("/treeData")
@POST
@Consumes(MediaType.TEXT_PLAIN)
@Produces(MediaType.TEXT_PLAIN)
public String storeTreeData(
        @QueryParam("data") String data,
        @QueryParam("username") String username,
        @QueryParam("accID") String accID) {

        System.out.println("Data= " + data + "\nAccID= " + accID + "\nUsername= " + username);

        return "Done";
}

The problem is that all the variables are printed as null..
the storeTreeData function should find the data , username , accID variables through @QueryParam and store them isn’t that right?

Anyone know what’s the problem here?

PS:The xmlhttp request is initiallized correctly and the connection is made but the parameters are not passed on the server.

Answer 1

What you try to do:

@QueryParam is used to get parameters from the query of the request:

http://example.com/some/path?id=foo&name=bar

In this example id and name can be accessed as @QueryParam.

But you are sending the parameters in the body of your request.

What you should do:

To get the parameters from the body, you should use @FormParam together with application/x-www-form-urlencoded:

@Path("/treeData")
@POST
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
@Produces(MediaType.TEXT_PLAIN)
public Response storeTreeData(
        @FormParam("data") String data,
        @FormParam("username") String username,
        @FormParam("accID") String accID) {

    // Build a text/plain response from the @FormParams.
    StringBuilder sb = new StringBuilder();
    sb.append("data=").append(data)
      .append("; username=").append(username)
      .append("; accId=").append(accID);

    // Return 200 OK with text/plain response body.
    return Response.ok(sb.toString()).build();
}

Edit:

You should also use

req.setRequestHeader("Content-type","application/x-www-form-urlencoded");

in your JavaScript code.