如何在 Jooby 应用程序上正确设置 CORS

Question

I am creating an API with the Jooby framework mostly following this guide . I am also using Vue.js as the frontend. However I am having issues with CORS. When I try to do a get request from my Vue.js frontend I get the error No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin ' http://localhost:8081 ' is therefore not allowed access.

This is my Jooby application.conf file:

# add or override properties
# See https://github.com/typesafehub/config/blob/master/HOCON.md for more 
details
db = mem

schema = """

create table if not exists pets (

id int not null auto_increment,

name varchar(255) not null,

primary key (id)

);
"""
cors {
# Configures the Access-Control-Allow-Origin CORS header. Possibly values: 
*, domain, regex or a list of previous values.
# Example:
# "*"
# ["http://foo.com"]
# ["http://*.com"]
# ["http://foo.com", "http://bar.com"]
origin: "*"

# If true, set the Access-Control-Allow-Credentials header
credentials: true

# Allowed methods: Set the Access-Control-Allow-Methods header
allowedMethods: [GET, POST]

# Allowed headers: set the Access-Control-Allow-Headers header. Possibly 
values: *, header name or a list of previous values.
# Examples
# "*"
# Custom-Header
# [Header-1, Header-2]
allowedHeaders: ["X-Requested-With, Content-Type, Accept, Origin"]

# Preflight max age: number of seconds that preflight requests can be cached 
by the client
maxAge: 30m

# Set the Access-Control-Expose-Headers header
# exposedHeaders: []
}

And this is App.java file where I query the database

package org.jooby.guides;

import java.util.List;

import org.jooby.Jooby;
import org.jooby.Results;
import org.jooby.jdbc.Jdbc;
import org.jooby.jdbi.Jdbi;
import org.jooby.json.Jackson;
import org.skife.jdbi.v2.DBI;
import org.skife.jdbi.v2.Handle;

import com.typesafe.config.Config;

public class App extends Jooby {

{
use(new Jackson());

use(new Jdbc());

use(new Jdbi()
    // 1 dbi ready
    .doWith((final DBI dbi, final Config conf) -> {
      // 2 open a new handle
      try (Handle handle = dbi.open()) {
        // 3. execute script
        handle.execute(conf.getString("schema"));
      }
    }));


/** Pet API. */
use("/api/pets")
    /** List pets. */
    .get(req -> {
      return require(DBI.class).inTransaction((handle, status) -> {
        PetRepository repo = handle.attach(PetRepository.class);
        List<Pet> pets = repo.list();
        return pets;
      });
    })
    /** Get a pet by ID. */
    .get("/:id", req -> {
      return require(DBI.class).inTransaction((handle, status) -> {
        int id = req.param("id").intValue();

        PetRepository repo = handle.attach(PetRepository.class);
        Pet pet = repo.findById(id);
        return pet;
      });
    })
    /** Create a pet. */
    .post(req -> {
      return require(DBI.class).inTransaction((handle, status) -> {
        // read from HTTP body
        Pet pet = req.body(Pet.class);

        PetRepository repo = handle.attach(PetRepository.class);
        int petId = repo.insert(pet);
        pet.setId(petId);
        return pet;
      });
    })
    /** Update a pet. */
    .put(req -> {
      return require(DBI.class).inTransaction((handle, status) -> {
        // read from HTTP body
        Pet pet = req.body(Pet.class);

        PetRepository repo = handle.attach(PetRepository.class);
        repo.update(pet);
        return pet;
      });
    })
    /** Delete a pet by ID. */
    .delete("/:id", req -> {
      return require(DBI.class).inTransaction((handle, status) -> {
        int id = req.param("id").intValue();

        PetRepository repo = handle.attach(PetRepository.class);
        repo.deleteById(id);
        return Results.noContent();
      });
    });
}

public static void main(final String[] args) {
run(App::new, args);
}

}

How do I fix this?

Answer 1

From documentation you need to add a CorsHandler :

{
   use("*", new CorsHandler());
   ...
}

Properties are optional, unless you want to change a default value.

Answer 2

You can manually specify the header and the accept method (Jooby MVC)

Cors cors = new Cors()
                .withHeaders("Content-Type", "Accept", "Origin","Authorization")
                .withMethods("GET", "POST", "OPTIONS", "PUT", "DELETE");
pluginApp.use("*", new CorsHandler(cors));