Your “<b>” breaks it. If you remove it and add a newLine “n” it should work.
Like this:

String a = ("nThe current Project-Status is: " + test.get("status") + "n");
String b = "";
for (int i = 0; i < gates.length(); i++) {
   status = gates.getJSONObject(i).getString("status");
   String metric = gates.getJSONObject(i).getString("metricKey");
   b = b + ("Status: " + status + " | Metric: " + metric + "n");
}

Also you are returning plain text. So, to display it correctly add “produces = “text/plain” to return the formatted String.

@GetMapping(value = "/gates", produces = "text/plain")

Then your output will be displayed with line breaks. This way u can apply further formatting.

I have the following code:

@Controller
public class GatesController {

    @RequestMapping ("/gates")

    public static String qualityGates(String x) throws IOException {
        try {
            System.out.println("n------QualityGates------");
            URL toConnect = new URL(x);
            HttpURLConnection con = (HttpURLConnection) toConnect.openConnection();
            System.out.println("Sending 'GET' request to URL : " + x);

            BufferedReader in = new BufferedReader(
                    new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuffer response = new StringBuffer();
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }

            in.close();

            //Cast the JSON-File to a JSONObject
            JSONObject res = new JSONObject(response.toString());
            JSONArray gates = new JSONArray(res.getJSONObject("projectStatus").getJSONArray("conditions").toString());
            JSONObject test = new JSONObject(res.getJSONObject("projectStatus").toString());

            String a = ("nThe current Project-Status is: " + test.get("status") + "n");
            String b = "";
            for (int i = 0; i < gates.length(); i++) {
                String status = gates.getJSONObject(i).getString("status");
                String metric = gates.getJSONObject(i).getString("metricKey");
                b = b + ("<b>Status: " + status + " | Metric: " + metric);

            }

            System.out.println(a+b);
            return a + b;
        } catch (Exception e) {
            System.out.println(e);
            return String.format("Error");
        }
    }

@SpringBootApplication
@RestController
public class SonarQualityGatesApplication {

    public static void main(String[] args) throws IOException {
        ConfigurableApplicationContext context=SpringApplication.run(SonarQualityGatesApplication.class, args);
        TestController b = context.getBean(TestController.class);


    }

    @GetMapping("/hello")
    public String hello(@RequestParam(value = "name", defaultValue = "World") String name) {
        return String.format("Hello %s!", name);
    }

    @GetMapping("/gates")
    public String gates() throws IOException {
        String temp = qualityGates("http://localhost:9000/api/qualitygates/project_status?projectKey={PROJECT_KEY}");
        return temp;
    }

}

The problem is currently the website looks like this:

Website_Curr

But I want a new line for every metric not in one row.
As you see I tried to add <b> at the string connotation
Do you have an idea how to fix this? It is my first web application I am a bit stuck.

I appreciate every help!