JSON response from spring boot rest controller getting repeated - json

I was trying to build a rest api using Spring boot 1.5.9.RELEASE and been stuck on this issue. The post request to api end points works just fine but when comes to get requests the result gets repeated. The response which the app produces for get request is
{"data":["Administrator"]}{"data":["Administrator"]}
The associated request mapping class code
#RequestMapping("/get")
public ResponseEntity getAllRoles()throws Exception{
List<Roles> roles = rolesService.getRoles();
Set<String> roleNames = new HashSet<>();
for(Roles r : roles)
roleNames.add(r.getRoleName());
return new ResponseEntity(new Response(roleNames), HttpStatus.OK);
}
The Response class
public class Response<T> {
private T data;
public Response() {}
public Response(T data) {
this.data = data;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
}
Any ideas about how to solve the issue? Thanks in advance

You are creating response twice, use below
RequestMapping("/get")
public ResponseEntity<?> getAllRoles()throws Exception{
List<Roles> roles = rolesService.getRoles();
Set<String> roleNames = new HashSet<>();
for(Roles r : roles)
roleNames.add(r.getRoleName());
return new ResponseEntity<Object>(roleNames, HttpStatus.OK);
}

Injecting #JsonProperty("yourFiledName") at the getter method works for me.
`
public class Response {
private T data;
public Response() {}
public Response(T data) {
this.data = data;
}
#JsonProperty("data")
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
}
`

Related

How to redirect into HTML static page from the Spring Boot genericResponse method

Im very new to the Spring boot. according to the client requirement my other member developed code segment using spring boot to get user response from here. Here is the code segment.
public GenericResponse updateAcceptOrReject(String password, FileAcceptStatus status) {
// TODO Auto-generated method stub
GenericResponse genericResponse = new GenericResponse();
String sql = "SELECT * FROM employee WHERE pass_code = ?";
Employee employee = null;
try {
employee = (Employee) jdbcTemplate.queryForObject(sql, new Object[] { password }, new EmployeeRowMapper());
} catch (EmptyResultDataAccessException e) {
System.out.println("error :"+ e.getLocalizedMessage());
employee = null;
}catch (Exception e) {
System.out.println("error :"+ e.getLocalizedMessage());
employee = null;
}
// check if employee available
if(employee == null) {
genericResponse.setStatusCode(200);
genericResponse.setMessage("No employee found");
return genericResponse;
}
// check acceptStatus
if(employee.getAccept_status() != 0) {
genericResponse.setStatusCode(201);
genericResponse.setMessage("You already accepted");
return genericResponse;
}
String updateSql = "update employee set accept_status=? where pass_code=?";
int[] types = {Types.INTEGER, Types.VARCHAR};
int updatedFlag = jdbcTemplate.update(updateSql, new Object[] { status.ordinal(), password }, types);
if(updatedFlag == 1) {
genericResponse.setStatusCode(0);
genericResponse.setMessage("Success");
return genericResponse;
}else {
genericResponse.setStatusCode(-99);
genericResponse.setMessage("Error occured while updating employ");
return genericResponse;
}
}
what i want is load separate static HTML page with a Success message located in another package rather that stating Success message in genericResponse.setMessage(). likewise static pages for other messages too.
Can anyone help me here?
Controller is like
#RestController
public class HumanResourceController {
#Autowired
private HumanResourceService hRService;
#RequestMapping(value = "/update/status/{password:.+}/{status}", method = RequestMethod.GET)
public ResponseEntity<?> updateAcceptOrReject(#PathVariable("password") String password,
#PathVariable("status") FileAcceptStatus status) {
GenericResponse genericResponse = hRService.updateAcceptOrReject(password, status);
return ResponseEntity.ok().body(genericResponse);
}
}
The #RestController will always return json message, so you should change it to #Controller, then you need to create a viewresolver to render the static html
move all your html file into /WEB-INF/
#Configuration
#EnableWebMvc
public class MvcConfiguration extends WebMvcConfigurerAdapter{
#Bean
public ViewResolver getViewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/");
resolver.setSuffix(".html");
return resolver;
}
#Override
public void configureDefaultServletHandling(
DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
}
#Controller
public class HumanResourceController {
#Autowired
private HumanResourceService hRService;
#RequestMapping(value = "/update/status/{password:.+}/{status}", method = RequestMethod.GET)
public String updateAcceptOrReject(#PathVariable("password") String password,
#PathVariable("status") FileAcceptStatus status) {
GenericResponse genericResponse = hRService.updateAcceptOrReject(password, status);
// you can return various view according the generic response http code
return "alreadyaccepted";
}
}

#RestController custom ResponseEntity - Jackson

What i'm trying to achieve here is to get a custom response from the RequestMapping, below is the structure of the json which I'm trying to get in case of an array of objects:
{
"error": false,
"message": "the message",
"data": [{},{},...]
}
and the below in case of object
{
"error": false,
"message": "the message",
"data": {}
}
The code is working fine but the problem is "data" will not always has an array, it may store an object, so what I tried is to create a custom POJO class which contains my custom response and when I want to annotate two attributes with same name i'm getting the below error
Could not find acceptable representation
And what if I create another class which will contain the same attributes but with an JsonObject not with array, is there any better way to achieve this ?
Below are my classes :
#JsonInclude(Include.NON_NULL)
public class JsonResponseObject<T> implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private boolean error;
private String message ;
#JsonProperty(value="data")
private ArrayList<T> array;
#JsonProperty(value="data")
private Object object ;
public JsonResponseObject() {
}
public boolean isError() {
return error;
}
public void setError(boolean error) {
this.error = error;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public ArrayList<T> getArray() {
return array;
}
public void setArray(ArrayList<T> array) {
this.array = array;
}
public Object getObject() {
return object;
}
public void setObject(Object object) {
this.object = object;
}
}
UserJsonController.java :
#RestController()
#RequestMapping(value = "/json")
public class UserJsonController {
#Autowired
private UserRepository userDAO;
#RequestMapping(value = "/users", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Object> getUsers() {
ArrayList<Users> entityList = (ArrayList<Users>) userDAO.findAll();
JsonResponseObject<Users> jsonResponse = new JsonResponseObject<Users>();
jsonResponse.setError(false);
jsonResponse.setMessage("test");
jsonResponse.setArray(entityList);
return new ResponseEntity<>(jsonResponse, HttpStatus.OK);
}
#RequestMapping(value = "/users/{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Object> getUserByID(#PathVariable int id) {
JsonResponseObject<Users> jsonResponse = new JsonResponseObject<Users>();
jsonResponse.setError(false);
jsonResponse.setMessage("test");
jsonResponse.setObject(userDAO.findById(id).get());
return new ResponseEntity<>(jsonResponse, HttpStatus.OK);
}}

#ComponentScan JSON information replaces the HTML views

Maybe the title is not the best to explain the problem, but I'll try to explain it as best as possible.
I have an Spring Boot Application using JPA and MySQL, so in order to check everything worked properly, I made a simple CRUD test for my database, and I found problems with autowiring which are explained in my previous question. The solution for those problems was just adding the #ComponentScan annotation to my Application.java.
It was the solution for the test because it run without problems, but then I find another problem. Apart from the test, I need my application to show a list of Proposals made by some Users and also some Comments. Before adding that annotation, the HTMLs showed the correct information, but after adding it shows information about the database in JSON format on the main page and if I try to navigate to "localhost:8080/viewProposal" p.e. it shows a WhiteLabel error page with error code 404. I have no idea why it is replacing the HTMLs because I have just one controller and is not a RESTController. These are my classes:
Application.java
#SpringBootApplication
#EntityScan("persistence.model")
#EnableJpaRepositories("persistence.repositories")
#ComponentScan("services.impl")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
MainController.java
#Controller
#RequestMapping("/")
public class MainController {
private static final Logger logger = Logger.getLogger(MainController.class);
private List<SseEmitter> sseEmitters = Collections.synchronizedList(new ArrayList<>());
private Map<String, Proposal> proposals = generateProposals();
#RequestMapping({"/live","/"})
public String landing(Model model) {
return "index";
}
#RequestMapping("/viewProposal")
public String viewProposal(Model model, Long id) {
//put the object in the map
return "viewProposal";
}
#KafkaListener(topics = "newVote")
public void listen(String data) {
String[] contents = data.split(";");
if(contents.length!=2)
return;
Proposal p;
int newVote;
if (proposals.containsKey(contents[0]))
p = proposals.get(contents[0]);
else {
p = new Proposal();
p.setTitle(contents[0]);
proposals.put(p.getTitle(), p);
}
if (contents[1].equals("+"))
newVote = +1;
else if (contents[1].equals("-"))
newVote = -1;
else
newVote = 0;
p.setNumberOfVotes(p.getNumberOfVotes() + newVote);
logger.info("New message received: \"" + data + "\"");
}
private static Map<String, Proposal> generateProposals() {
Map<String, Proposal> lista = new HashMap<String, Proposal>();
Proposal p = new Proposal();
p.setTitle("tituloPrueba");
lista.put("tituloPrueba", p);
return lista;
}
#ModelAttribute("proposals")
public Map<String, Proposal> getProposals() {
return proposals;
}
public void setProposals(Map<String, Proposal> proposals) {
this.proposals = proposals;
}
}
MvcConfiguration
#Configuration
#EnableWebMvc
public class MvcConfiguration extends WebMvcConfigurerAdapter{
#Bean
public ViewResolver getViewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/resources/templates/");
resolver.setSuffix(".html");
return resolver;
}
#Override
public void configureDefaultServletHandling(
DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
#Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.defaultContentType(MediaType.TEXT_HTML);
}
}
If you want to see the rest of the classes, please go to my previous question everything is in there.
Thanks in advance.

Node.js equivalent for GSON Json creation?

I have a Java class in a servlet that uses GSON to render posted JSON Strings into a Java object. The beauty of the approach is, that GSON filters out all JSON elements that don't match a class property, so I never end up with JSON content that I don't want to process. The servlet's doPost (simplified) looks like this:
protected void doPost(HttpServletRequest request, HttpServletResponse response) {
PrintWriter out = null;
try {
InputStream in = request.getInputStream();
Demo d = Demo.load(in);
in.close();
response.setContentType("text/plain");
response.setStatus(HttpServletResponse.SC_OK);
out = response.getWriter();
out.println(d.toJson);
} catch (Exception e) {
e.printStackTrace();
out.println(e.getMessage());
}
out.close();
}
The Demo class (and that's the one I need to recreate in common.js or node.js looks like this:
#JsonIgnoreProperties(ignoreUnknown = true)
public class Demo implements Serializable {
public static Demo load(InputStream in) {
Demo result = null;
try {
Gson gson = new GsonBuilder().create();
result = gson.fromJson(new InputStreamReader(in), Demo.class);
} catch (Exception e) {
result = null;
}
return result;
}
#TypeDiscriminator
#JsonProperty("_id")
private String id = UUID.randomUUID().toString();
private Date created = new Date();
private String color;
private String name;
private String taste;
public String getColor() {
return this.color;
}
public String getName() {
return this.name;
}
public String getTaste() {
return this.taste;
}
public Date getCreated() {
return this.created;
}
public String getId() {
return this.id;
}
public void setName(String name) {
this.name = name;
}
public void setTaste(String taste) {
this.taste = taste;
}
public void setColor(String color) {
this.color = color;
}
public String toJson() {
GsonBuilder gb = new GsonBuilder();
gb.setPrettyPrinting();
gb.disableHtmlEscaping();
Gson gson = gb.create();
return gson.toJson(this);
}
}
Obviously I stripped out all the processing logic and the servlet just echos the JSON back, which is not what the app does, but serves to illustrate the point. I can throw pretty any String in a HTTP Post at that example and I only get valid Demo objects.
How would I do something like this in node.js?
Node.js is Javascript so has built in support for json. You can use JSON.parse to convert from string to json and wrap in try catch block.
To only include select properties there is no built in feature in node that I know of unless you are using Mongodb with mongoose, but you could do following: Have a "class" that is an object containing all properties that you want and delete those from parsed json object that are not in that "class" object.
var class = {x: null, y:null};
for(var prop in object){
if (!class.hasOwnProperty (prop)) {
delete object [prop]
}
It would be best to use this class as object and expose parseJSON function to encapsulate this functionality

Jersey unmarshal JSON: Last element null does not work

I am using Jersey to parse the following JSON:
{"response":{"status":"OK","campaigns":[{"id":12345,"state":"active","code":null}]}}
But I get the following error message:
java.lang.IllegalArgumentException: No more parsing elements.
If I switch the position of the fields code and state so that the resulting JSON looks like
{"response":{"status":"OK","campaigns":[{"id":12345,"code":null,"state":"active"}]}}
everything works fine. Also if I change the code-field in the first JSON to a non-null value like "code":"test", Jersey can parse this without any problems. I tried other more complex examples always getting the above mentioned error message when leaving the last field of any element of an array null.
I think I am doing something wrong, because I could not find any others having the similar problem. I already tried to implement a CustomJAXBContextResolver using other JSON notations like natural but nothing worked for me.
Any ideas?
Here are my binding classes:
#XmlRootElement
public class LoadEntityResponse {
public LoadEntityResponse() {
}
private Response response;
public Response getResponse() {
return response;
}
public void setResponse(Response response) {
this.response = response;
}
}
and
public class Response {
public Response() {
}
private String status;
private String error;
private String error_id;
private Campaign[] campaigns;
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getError() {
return error;
}
public void setError(String error) {
this.error = error;
}
public String getError_id() {
return error_id;
}
public void setError_id(String error_id) {
this.error_id = error_id;
}
public Campaign[] getCampaigns() {
return campaigns;
}
public void setCampaigns(Campaign[] campaigns) {
this.campaigns = campaigns;
}
}
and finally
public class Campaign{
public Campaign() {
}
protected int id;
protected String code;
protected String state;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
}
Solved: Using JacksonJsonProvider now:
...
DefaultClientConfig config = new DefaultClientConfig();
config.getClasses().add(JacksonJsonProvider.class);
...
that´s all!
You can also use Jackson POJO support that comes with jersey-json but there is a need to do some configuration, see POJO support in Jersey User Guide.
Try using Genson http://code.google.com/p/genson/.
To enable it on client side use the following code:
ClientConfig config = new DefaultClientConfig();
config.getClasses().add(GensonJsonConverter.class);
cli = Client.create(config);
EDIT: on server side there is no configuration needed, when the jar is in your classpath json support is automatically enabled.