在Spring Boot中将JSON文件作为JSONArray返回

Question

I am developing a Spring Boot application in which I have a JSON properties file:

{
    data: [
        {"firstWebServiceUrl":"http://localhost:8080/firstUrl/"},
        {"secondWebServiceUrl":"http://localhost:8080/secondUrl/"},
    ]
}

I have created a controller to read and return this file as org.json.JSONArray object:

@RestController
@RequestMapping("/Test")
public class MainController {

    @RequestMapping(value = "/getJsonProperties", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
    public JSONArray getJsonProperties() {
        Resource resource = new ClassPathResource("/static/configs/properties.json");
        InputStream resourceAsStream;
        JSONObject jsonObject = null;
        JSONArray jsonArray = null;
        String resourceAsString = null;
        try {
            resourceAsStream = resource.getInputStream();
            byte[] resourceInBytes = IOUtils.toByteArray(resourceAsStream);
            resourceAsString = new String(resourceInBytes);
            jsonObject = new JSONObject(resourceAsString);          
            jsonArray = jsonObject.getJSONArray("data");
            System.out.println("json array object is " + jsonArray);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return jsonArray;
    }

}

When i call this method I see the output in the console (thanks to sysout):

json array object is [{"firstWebServiceUrl":"http://localhost:8080/firstUrl/"},{"secondWebServiceUrl":"http://localhost:8080/secondUrl/"}]

as expected. However when I call this method from the browser by entering the url: http://localhost:8090/Test/getJsonProperties I get the output:

{"empty":false}

instead of the contents. How can I return the contents?

Answer 1

Return a String instead of JSONArray because there is no default converter that could serialize a JSONArray into a JSON string:

@RestController
@RequestMapping("/Test")
public class MainController {

    @RequestMapping(value = "/getJsonProperties", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
    public String getJsonProperties() {
        Resource resource = new ClassPathResource("/static/configs/properties.json");
        InputStream resourceAsStream;
        JSONObject jsonObject = null;
        JSONArray jsonArray = null;
        String resourceAsString = null;
        try {
            resourceAsStream = resource.getInputStream();
            byte[] resourceInBytes = IOUtils.toByteArray(resourceAsStream);
            resourceAsString = new String(resourceInBytes);
            jsonObject = new JSONObject(resourceAsString);          
            jsonArray = jsonObject.getJSONArray("data");
            System.out.println("json array object is " + jsonArray);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return jsonArray != null ? jsonArray.toString() : "[]";
    }

}