Question

我知道这个问题已经发布在这里了，但是我被困在某一点上，我没有得到确切的解决方案，所以在这里再次发布。

我在Jersey上编写了一个简单的RESTFul Web服务。在POST方法中，我在请求中传递JSON对象。

我正在使用带注释的@XmlRootElement类，并且它也用于POST方法。

代码如下所示 - 我的POJO课程

  @XmlRootElement
public class WelcomeForm {
    public String title;

    public WelcomeForm(){
        title = "";
    }

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

Web服务如下

    @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;
    }
}

当我尝试通过在请求中传递json对象来运行简单的html代码时出现错误

/* 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

然后我添加了Custom Filer Class，以解决Access-Control-Origin不允许错误

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;
}

}

但它没用，我又得到了同样的错误。

这是我的HTML代码

<!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>

这有什么问题吗？我错过了什么吗？当我们得到Access-Control-Allow-Origin错误？我已经在web.xml文件中进行了更改以提及过滤器类

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

我错过了其他什么吗？

Answer 1

错误（实际上并非错误） com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes 信息：无法找到类java.lang.String

的语法元素

与跨域问题无关。

我不确定为什么它发生了我已经读过它与使用默认构造函数和@XmlRootElement有关。无论如何要摆脱它的2个选项

@OPTIONS
public Response myResource() {

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

或禁用web.xml中的wadl

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

带有JERSEY的Web服务器的POST请求中的JSON对象

1 个答案: