add cors config

src/main/java/com/jazavac/relaysim/RelaySimApplication.java

@@ -1,12 +1,29 @@
 package com.jazavac.relaysim;
 
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
+@Slf4j
 @SpringBootApplication
 public class RelaySimApplication {
 
   public static void main(String[] args) {
     SpringApplication.run(RelaySimApplication.class, args);
   }
+
+  @Bean
+  public WebMvcConfigurer corsConfigurer() {
+    return new WebMvcConfigurer() {
+      @Override
+      public void addCorsMappings(CorsRegistry registry) {
+        log.info("Adding cors mapping");
+        registry.addMapping("/**").allowedOrigins("*");
+      }
+    };
+  }
 }

src/main/java/com/jazavac/relaysim/controller/RelayApiController.java

@@ -3,6 +3,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import javax.servlet.http.HttpServletResponse;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.CrossOrigin;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -11,6 +12,7 @@
  * This class is used to simulate turning a relay on and off, as well as getting the current state
  */
 @RestController
+@CrossOrigin
 @Slf4j
 public class RelayApiController {
 
@@ -19,8 +21,6 @@ public class RelayApiController {
   @GetMapping("/status")
   public String returnStatus(HttpServletResponse response) {
     log.debug("Client requesting GET /status");
-    response.addHeader("Access-Control-Allow-Origin", "*");
-    response.addHeader("Content-Type", "application/json");
     return String.format("{\"relayIsOn\":%b}", relayIsOn.get());
   }