'origin 'http://localhost:4200' has been blocked by CORS policy in Angular7
I want to use of http://5.160.2.148:8091/api/trainTicketing/city/findAll rest for get cities in my angular project.
I used version 7.2.15 of angular in my project.
when get this url with httpClient throw following error :
Access to XMLHttpRequest at 'http://5.160.2.148:8091/api/trainTicketing/city/findAll' from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
While at work correctly when enter url in browser and postman.
why ?
Solution 1:[1]
Solution 1 - you need to change your backend to accept your incoming requests
Solution 2 - using Angular proxy see here
Please note this is only for
ng serve, you can't use proxy inng build
Solution 3 - IF your backend accepts requests from a wildcard domanin like *.mydomain.com then you can edit your hosts file and add 127.0.0.1 local.mydomain.com in there, then in your browser instead of localhost:4200 enter local.mydomain.com:4200
Note: the reason it's working via postman is postman doesn't send preflight requests while your browser does.
Solution 2:[2]
For .NET CORE 3.1
I was using https redirection just before adding cors middleware and able to fix the issue by changing order of them
What i mean is:
change this:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
...
app.UseHttpsRedirection();
app.UseCors(x => x
.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader());
...
}
to this:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
...
app.UseCors(x => x
.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader());
app.UseHttpsRedirection();
...
}
By the way, allowing requests from any origins and methods may not be a good idea for production stage, you should write your own cors policies at production.
Solution 3:[3]
if You use spring boot , you should add origin link in the @CrossOrigin annotation
@CrossOrigin(origins = "http://localhost:4200")
@GetMapping("/yourPath")
You can find detailed instruction in the https://spring.io/guides/gs/rest-service-cors/
Solution 4:[4]
You are all good at Angular side even postman not raise the cors policy issue. This type of issue is solved at back-end side in major cases.
If you are using Spring boot the you can avoid this issue by placing this annotation at your controller class or at any particular method.
@CrossOrigin(origins = "http://localhost:4200")
In case of global configuration with spring boot configure following two class:
`
@EnableWebSecurity
@AllArgsConstructor
public class SecurityConfig extends WebSecurityConfigurerAdapter {
@Override
public void configure(HttpSecurity httpSecurity) throws Exception{
httpSecurity.csrf().disable()
.authorizeRequests()
.antMatchers("/api1/**").permitAll()
.antMatchers("/api2/**").permitAll()
.antMatchers("/api3/**").permitAll()
}
`
@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
@Override
public void addCorsMappings(CorsRegistry corsRegistry) {
corsRegistry.addMapping("/**")
.allowedOrigins("http://localhost:4200")
.allowedMethods("*")
.maxAge(3600L)
.allowedHeaders("*")
.exposedHeaders("Authorization")
.allowCredentials(true);
}
Solution 5:[5]
The solution needs to add these headers to the server response.
'Access-Control-Allow-Origin', '*'
'Access-Control-Allow-Methods', 'GET,POST,OPTIONS,DELETE,PUT'
If you have access to the server, you can add them and this will solve your problem
OR
You can try concatentaing this in front of the url:
https://cors-anywhere.herokuapp.com/
Solution 6:[6]
Follow these steps
- Add cors dependency. type the following in cli inside your project directory
npm install --save cors
- Include the module inside your project
var cors = require('cors');
- Finally use it as a middleware.
app.use(cors());
Solution 7:[7]
Startup.cs in WebAPI.
app.UseCors(options => options.AllowAnyOrigin());
In ConfigureServices method:
services.AddCors(c =>
{
c.AddPolicy("AllowOrigin", options => options.AllowAnyOrigin());
});
In Controller:
[HttpGet]
[Route("GetAllAuthor")]
[EnableCors("AllowOrigin")]
Solution 8:[8]
For temporary testing during development we can disable it by opening chrome with disabled web security like this.
Open command line terminal and go to folder where chrome is installed i.e. C:\Program Files (x86)\Google\Chrome\Application
Enter this command:
chrome.exe --user-data-dir="C:/Chrome dev session" --disable-web-security
A new browser window will open with disabled web security. Use it only for testing your app.
Solution 9:[9]
If your project is .net Core 3.1 API project.
update your Startup.cs in your .net core project to:
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
readonly string MyAllowSpecificOrigins = "_myAllowSpecificOrigins";
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddCors(options =>
{
options.AddPolicy(MyAllowSpecificOrigins,
builder =>
{
builder.WithOrigins("http://localhost:53135",
"http://localhost:4200"
)
.AllowAnyHeader()
.AllowAnyMethod();
});
});
services.AddDbContext<CIVDataContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("CIVDatabaseConnection")));
services.AddControllers();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseCors(MyAllowSpecificOrigins);
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
Solution 10:[10]
For nodejs use the below code
res.setHeader('Access-Control-Allow-Origin', 'http://localhost:4200');
Solution 11:[11]
1: Create a class WebMvcConfig and extend it as shown from the WebMvcConfiguration and override addCorsMappings method.
2: Most importantly don't forget to make it @Configuration annotation because it should be loaded with Main Spring class to allow Cross-Origin.
@Configuration
public class WebMvcCofig implements WebMvcConfigurer{
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/*")
.allowedOrigins("*")
.allowedMethods("*")
.allowedHeaders("*")
.allowCredentials(true);
}
}
Solution 12:[12]
In my case using Angular and Spring Boot I solved that issue in my SecurityConfig:
http.csrf().disable().cors().disable()
.authorizeRequests()
.antMatchers(HttpMethod.POST, "/register")
.anonymous()
.anyRequest().authenticated()
.and()
.sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);
Or replace that line to:
http.csrf().disable().cors().and()
And other test option is to delete dependency from pom.xml and other code depend on it. It's like turn off security from Spring:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
<version>2.3.3.RELEASE</version>
</dependency>
Solution 13:[13]
Create a class and add the below configuration in the spring boot application.
package com.myapp.springboot.configs;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebMvcConfiguration implements WebMvcConfigurer {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/*").
allowedOrigins("*").
allowedMethods("*").
allowedHeaders("*").
allowCredentials(true);
}
}
Solution 14:[14]
I tried all the solutions given above and worked while using nodejs backend but unfortunately while working with python it dint work, so I ended up installing a plugin Allow CORS, atleast this plugin helped
Solution 15:[15]
If you are using spring-boot for server side coding then please add a servlet filter and add the following code of your spring-boot application. It should work. Adding "Access-Control-Allow-Headers", "*" is mandatory. Creation of proxy.conf.json is not needed.
@Component
@Order(1)
public class MyProjectFilter implements Filter {
@Override
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-Expose-Headers", "Content-Disposition");
response.setHeader("Access-Control-Allow-Methods", "GET,POST,PATCH,DELETE,PUT,OPTIONS");
response.setHeader("Access-Control-Allow-Headers", "*");
response.setHeader("Access-Control-Max-Age", "86400");
chain.doFilter(req, res);
}
}
Solution 16:[16]
I Tried adding the below statement on my API on the express server and it worked with Angular8.
app.use((req, res, next) => {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Methods", "GET , PUT , POST , DELETE");
res.header("Access-Control-Allow-Headers", "Content-Type, x-requested-with");
next(); // Important
})
Solution 17:[17]
- If you are using spring boot application then just add @CrossOrigin in your Controller and import the statement import org.springframework.web.bind.annotation.CrossOrigin; that set and run the application again
Solution 18:[18]
If you use Spring boot 2 you can add CrossOrigin annotation in the controller class
@CrossOrigin(origins = "http://localhost:4200", maxAge = 3600)
it worked for me !
Solution 19:[19]
There are so many ways to handle the issue of CORs in spring boot, the easiest way is to just put the @CrossOrigin annotation on top of the Controller may be in your ..resource java file. Try
@CrossOrigin(origins= {"*"}, maxAge = 4800, allowCredentials = "false" @RestController
for more info read spring boot CORs docs. Thank you.
Solution 20:[20]
If you are using Angular with Dotnet Core:
On class Startup.cs
On method ConfigureServices add:
services.AddCors();
On method Configure add
app.UseCors(options => options.AllowAnyHeader().AllowAnyMethod().WithOrigins("http://localhost:4200"));
Solution 21:[21]
In my case I saw the error:
Access to XMLHttpRequest at 'localhost:5000/graphql' from origin 'http://localhost:4200' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, brave, chrome-untrusted, https.
Make sure to include a protocol (http or https) in your urls.
const uri = 'http://localhost:5000/graphql'; //
Solution 22:[22]
If you using node as a backend you can use this. Just add these lines on the server.js "API" side in Node.js, before that make sure to install "cors"
const express = require('express');
const app = express();
app.use(express.json());
var cors = require('cors');
app.use(cors());
Solution 23:[23]
Normal REST API IN JAVA CROS POLICY
@GET
@Path("getsample")
@Produces(MediaType.APPLICATION_JSON)
public Response getOptions() {
Map<String,String> map=new HashMap<String,String>();
// map.put("response",res);
map.put("name","Ajay");
map.put("id","20");
map.put("clg", "SLICA");
return Response.ok()
.header("Access-Control-Allow-Origin", "*")
.header("Access-Control-Allow-Methods", "POST, GET, PUT, UPDATE, OPTIONS")
.header("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With")
.entity(map)
.build();
}
Solution 24:[24]
If by Any chance you are using fireBase as a dataBase you need to add ".json" to the end of the link, this solved the issue for me
cors error: https://uar-test-bd448-default-rtdb.firebaseio.com/rules
NO ERROR: https://uar-test-bd448-default-rtdb.firebaseio.com/rules.**json**
Solution 25:[25]
if using Nodejs(Back-End) with application angular install the cors in NodeJs npm install --save cors
var cors = require('cors');
app.use(cors());
Solution 26:[26]
Nestjs
app.enableCors({ origin: "*" });
Allows any origin. I recommend only allowing this in development mode.
Sources
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Source: Stack Overflow