No 'Access-Control-Allow-Origin' error wit

问题:

I create a RESTful API with Spring boot and host it in Pivotal web services.

Let's say the url is https://abc.cfapps.io/students and the json result will be

[

       {"id":1,"name":"Michael","score":8.5},
       {"id":2,"name":"Naomi","score":5.6}
]

Then I write an Angular client to send a request to that url:

angular.module("app", []).controller("listController", function($scope, $http)
{
    var url = 'https://abc.cfapps.io/students';
    var httpRequest = new XMLHttpRequest();
    httpRequest.open('GET', url, true);
    httpRequest.setRequestHeader('Access-Control-Allow-Origin', '*');
    httpRequest.setRequestHeader('Content-Type', 'application/json');
    httpRequest.onerror = function (XMLHttpRequest, textStatus, errorThrown) {
        console.log('failed');
        console.log(JSON.stringify(XMLHttpRequest));
    };
    httpRequest.onload = function () {
        console.log('SUCCESS!');
    }
    httpRequest.send();        
});

My client run in localhost:52442 and in my Spring boot service I also allow CORS, too.

@RestController
@CrossOrigin(origins = "http://localhost:52442")
@RequestMapping(value="/students")
public class StudentService
{

    @RequestMapping(value="/",method = RequestMethod.GET)
    public ArrayList<Student> getListStudents()
    {
        // return list
    }

// other methods
}

But I keep getting this error:

XMLHttpRequest cannot load https://abc.cfapps.io/students.         
Response to preflight request doesn't pass access control check:     
No 'Access-Control-Allow-Origin' header is present on the requested resource.        
Origin 'http://localhost:52442' is therefore not allowed access. The response had HTTP status code 403.

回答1:

If your using the java code at backend

We can try to configure it in this way by creating a class for it

   package com.web;

   import org.springframework.stereotype.Component;

   import javax.servlet.*;
   import javax.servlet.http.HttpServletResponse;
   import java.io.IOException;

/**
 * Note this is a very simple CORS filter that is wide open.
 * This would need to be locked down.
 */
@Component
public class CORSFilter implements Filter {

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        chain.doFilter(req, res);
    }

    public void init(FilterConfig filterConfig) {}

    public void destroy() {}

}

I think this might be useful

回答2:

Try the below format of $http GET call with header's set to allow cross origin

    $http({method: 'GET',
           url: 'https://abc.cfapps.io/students',
           cache:false,
           headers: {
                'Access-Control-Allow-Origin': '*',
                'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS',
                'Access-Control-Allow-Headers': 'Content-Type, X-Requested-With',
                'X-Random-Shit':'123123123'
            }})
            .success(function(outputData) {
    });