AngularJS $ http获取方法错误，例如“响应预检请求”

Question

 $http({
    method: 'GET',
    url : 'http: //esbuatt1wm.ito.unisys.com:7001/invoke/wm.server/ping',
        timeout: 10000,
    headers: {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET,POST,PUT,DELETE,OPTIONS,JSONP',
        'Content-Type': '*',
        'Access-Control-Allow-Headers': 'Content-Type',
        'Access-Control-Allow-Credentials': 'true'
    },
    params: {}, // Query Parameters (GET)
    transformResponse: function(data, status, headers, config) {
        console.log('transferms data ' + data);
        // string -> XML document object
        return $.parseXML(data);
    }
 }).success(function(data, status, headers, config) {
    // XML document object
    $scope.xml = data.documentElement.innerHTML;
    console.dir('xml data ' + $scope.xml);
 }).error(function(data, status, headers, config) {
    $window.alert('ERROR.');
 });

#############Error

XMLHttpRequest cannot load http://esbuatt1wm.ito.unisys.com:7001/invoke/wm.server/ping . 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:1337 ' is therefore not allowed access.

Answer 1

Use following code in config function

config(function($httpProvider) {
    $httpProvider.defaults.useXDomain = true;
    delete $httpProvider.defaults.headers.common['X-Requested-With'];
});

Answer 2

Providing header will not help you, as you still hitting the server from you local ie localhost. The issue is when you hit sever from local, server will treat the request as of different domain request.

Either you can use express.js, (express is a server). In this case, server is communicating with server so, this error will get removed.

Or if at the server you trying to hit, your backend code persists, enable CORS request for that particular call or any other call when you will make.

If you are using spring boot you can use the following code:

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

@Component
public class SimpleCORSFilter implements Filter {

private final Logger log = LoggerFactory.getLogger(SimpleCORSFilter.class);

public SimpleCORSFilter() {
    log.info("SimpleCORSFilter init");
}

@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) res;

    response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));
    response.setHeader("Access-Control-Allow-Credentials", "true");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With, remember-me");

    chain.doFilter(req, res);
}

@Override
public void init(FilterConfig filterConfig) {
}

@Override
public void destroy() {
}

}`

enabling it will solve your problem. These are two option by which you can overcome from this error.