无法在 JavaScript 中向 Java Web 服务(球衣)发出 CORS POST 请求?

2022-01-21 00:00:00 cors web-services javascript java jersey

我正在使用 Jersey 在 Java Web 服务中实现跨资源源共享.我创建的资源如下:

I am implementing Cross Resource Origin Sharing in Java Web services using Jersey.I created resource as followes:

@POST
    @Path("/getSubjects")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response getSubjects(TokenCheck tc) throws IOException, ServletException{ 
        String token = tc.getToken();
        String result = "";
        if(!token.equals("") && !token.equals(null)){
            context.getRequestDispatcher("/GetSubjectsWs?token="+token).include(request, response);
            String subs = request.getAttribute("subjects").toString();
            result = "{"subjects":""+subs+""}";
        }else {
            result = "{"subjects":"['Invalid Token login again']"}";
        }
        JSONObject j = null;
        try {
            j = new JSONObject(result);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return Response.status(200).entity(j).header("Access-Control-Allow-Origin", "*").header("Access-Control-Allow-Methods", "POST, GET, OPTIONS").header("Access-Control-Allow-Headers", "Content-Type:application/json").build(); 
    }

并使用 javascript 作为发布请求:

and making post request using javascript as :

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JavaScript Client</title>
<script type="text/javascript">
function restReq() {
    var url = "http://localhost:8888/WebservicesServer/restful/getserver/getSubjects";
    var json = {
            "token":"8495C211F11C9B18E6651E03EB2995BC"
    };
    var client = new XMLHttpRequest();
    client.open("POST", url, true);
    client.setRequestHeader("Access-Control-Request-Methods", "POST");
    client.setRequestHeader("Content-Type", "application/json");
    client.send(json);
    client.onreadystatechange = function() {
        if (client.readyState == 4) {
           if ( client.status == 200) 
               console.log("success: " + client.responseText);
          else
              console.log("error: " +client.status+" "+ client.responseText);
       }
 };
}
</script>
</head>
<body>
<input type="button" value="getSubjects" onclick="restReq();">
</body>
</html>

当我单击 chrome 中的 getSubjects 按钮时，我收到 错误:XMLHttpRequest 无法加载 ..localhost:8888/WebservicesServer/restful/getserver/getSubjects.Access-Control-Allow-Origin 不允许 Origin null.但我可以通过 GET 请求得到响应，问题在于 POST 请求我的浏览器 url file:///E:/​​Documents%20and%20Settings/Srinivas/Desktop/wars/JSClient2.html(文件系统)我尝试了很多方法，比如设置原点等，仍然无法得到 json 响应(服务器是 Tomcat 7)请帮助解决这个问题.

When i clicked getSubjects Button in chrome I am getting error as : XMLHttpRequest cannot load ..localhost:8888/WebservicesServer/restful/getserver/getSubjects. Origin null is not allowed by Access-Control-Allow-Origin. But i am able to get response with GET request,problem is with POST request my browser url file:///E:/Documents%20and%20Settings/Srinivas/Desktop/wars/JSClient2.html (File system) I tried in many ways like by setting origin etc, still unable to get json response (Server is Tomcat 7) please help to overcome this problem.

推荐答案

如果你正在使用 CORS，那么你应该将它作为一个过滤器来实现，而不是试图将它嵌入到每个资源的每个方法中.这是一个简单的示例(如果您担心，您可能需要调整设置以限制它):

If you are using CORS then you should implement it as a filter rather than attempt to embed it in every method of every resource. Here's a simple example (you might want to tweak the settings to restrict it if that's of concern to you):

import com.sun.jersey.spi.container.ContainerRequest;
import com.sun.jersey.spi.container.ContainerResponse;
import com.sun.jersey.spi.container.ContainerResponseFilter;

/**
 * Filter to handle cross-origin resource sharing.
 */
public class CORSFilter implements ContainerResponseFilter
{
  private static final String ORIGINHEADER = "Origin";
  private static final String ACAOHEADER = "Access-Control-Allow-Origin";
  private static final String ACRHHEADER = "Access-Control-Request-Headers";
  private static final String ACAHHEADER = "Access-Control-Allow-Headers";

  public CORSFilter()
  {
  }

  @Override
  public ContainerResponse filter(final ContainerRequest request, final ContainerResponse response)
  {
    final String requestOrigin = request.getHeaderValue(ORIGINHEADER);
    response.getHttpHeaders().add(ACAOHEADER, requestOrigin);

    final String requestHeaders = request.getHeaderValue(ACRHHEADER);
    response.getHttpHeaders().add(ACAHHEADER, requestHeaders);
    return response;
  }
}

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