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Why is spring returning me an empty llist?

I dont seem to know why Spring is returning me an empty list enough I have passed in a JSON.stringify() string from reactJS
This is my code for reactJS
postData(item){
console.log(item)
fetch("http://localhost:8080/addSuspect", {
"method": "POST",
"headers": {
"content-type": "application/json"
},
"body": item
})
.then(response => {
console.log(response);
})
.catch(err => {
console.log(err);
});
}
uploadFile(event) {
let file
let file2
//Check if the movements andsuspected case profiles are uploaded
if(event.target.files.length !== 2){
this.setState({error:true, errorMsg:"You need to upload at least 2 files!"})
return
}
//Check if the file is the correct file
console.log("Files:")
for (var i=0, l=event.target.files.length; i<l; i++) {
console.log(event.target.files[i].name);
if (event.target.files[i].name.includes("_suspected")){
file = event.target.files[i]
}
else if (event.target.files[i].name.includes("_movements")){
file2 = event.target.files[i]
}
else{
this.setState({error:true, errorMsg:"You have uploaded invalid files! Please rename the files to <filename>_suspected (For suspected cases) or <filename>_movement (For suspected case movement)"})
return
}
}
//Reads the first file (Suspected profile)
if (file) {
const reader = new FileReader();
reader.onload = () => {
// Use reader.result
const lols = Papa.parse(reader.result, {header: true, skipEmptyLines: true}, )
console.log(lols.data)
// Posting csv data into db
// this.postData('"' + JSON.stringify(lols.data) + '"')
this.postData(JSON.stringify(lols.data))
// Adds names into dropdown
this.setState({dataList: ["None", ...lols.data.map(names => names.firstName + " " + names.lastName)]})
const data = lols.data
this.setState({suspectCases: data})
}
reader.readAsText(file)
}
}
Here is what I get from console.log():
[{"id":"5","firstName":"Bernadene","lastName":"Earey","email":"bearey4#huffingtonpost.com","gender":"Female","homeLongtitude":"","homeLatitude":"","homeShortaddress":"","homePostalcode":"552209","maritalStatus":"M","phoneNumber":"92568768","company":"Yadel","companyLongtitude":"","companyLatitude":""},{"id":"14","firstName":"Mada","lastName":"Lafaye","email":"mlafayed#gravatar.com","gender":"Female","homeLongtitude":"","homeLatitude":"","homeShortaddress":"","homePostalcode":"447136","maritalStatus":"M","phoneNumber":"85769345","company":"Eare","companyLongtitude":"","companyLatitude":""}]
Below shows the Code in my Spring Controller
#RestController
public class HomeController {
private final profileMapper profileMapper;
private final suspectedMapper suspectedMapper;
public HomeController(#Autowired profileMapper profileMapper, #Autowired suspectedMapper suspectedMapper) {
this.profileMapper = profileMapper;
this.suspectedMapper = suspectedMapper;
}
#GetMapping("/listAllPeopleProfiles")
//Removes the CORS error
#CrossOrigin(origins = "http://localhost:3000")
private Iterable<Peopleprofile> getAllPeopleProfiles (){
return profileMapper.findAllPeopleProfile();
}
#GetMapping("/listAllSuspectedCases")
#CrossOrigin(origins = "http://localhost:3000")
private Iterable<Suspected> getAllSuspected(){
return suspectedMapper.findallSuspected();
}
#PostMapping("/addSuspect")
#CrossOrigin(origins = "http://localhost:3000")
private void newSuspectedcases(ArrayList<Suspected> unformattedcases){
// try {
// final JSONObject obj = new JSONObject(unformattedcases);
//
// System.out.println(obj);
//// ObjectMapper mapper = new ObjectMapper();
//// List<Suspected> value = mapper.writeValue(obj, Suspected.class);
// } catch (JSONException e) {
// e.printStackTrace();
// }
//
// Gson gson = new Gson();
// List<Suspected> suspectedCases = gson.fromJson(unformattedcases, new TypeToken<List<Suspected>>(){}.getType());
System.out.println(unformattedcases);
// for (Suspected suspected : suspectedCases){
// suspectedMapper.addSuspectedCase(suspected);
// }
}
}

I am not sure I understand your issue. This is my best guess about what you meant and what you want to happen :
You want your controller to receive ArrayList < Suspected > as the POST request body
You want your controller to return ArrayList < Suspected > as the POST response body
If that's the case, try this :
[...]
#PostMapping("/addSuspect")
#CrossOrigin(origins = "http://localhost:3000")
#ResponseBody
private ArrayList<Suspected> newSuspectedcases(#RequestBody ArrayList<Suspected> unformattedcases){
[...]
System.out.println(unformattedcases);
[...]
return unformattedcases;
}
If it's not what you meant, please provide more information.

Firstly, your controller method is returning void and not, if I undestand correctly, the payload that you're trying to send. You have to make your controller method return List<Suspected> to receive a body in the response.
Another issue is that you're missing a #RequestBody annotation on the param, which tells Spring to get the body from the request and try to deserialize it to a ArrayList of Suspects.
Another thing to note, it is a good practice to use interfaces instead of implementation classes as parameters and return value in your methods. Consider using List<Suspected> instead of ArrayList<Suspected>
So the final method should look like this:
#PostMapping("/addSuspect")
#CrossOrigin(origins = "http://localhost:3000")
private List<Suspected> newSuspectedcases(#RequestBody List<Suspected> unformattedcases){
[...]
System.out.println(unformattedcases);
[...]
return unformattedcases;
}
PS For CORS issues you may want to using a local proxy setup as described in React docs: https://create-react-app.dev/docs/proxying-api-requests-in-development/ And configure CORS for remote environments, without adding localhost:3000.

is it possible to return "if condition satisfies return a list else return an error message" using a java method

I know that in Java a method can return only one return type... But if there is any possiblity to this, kindly let me know. From the below method I am trying to return a list if condition satisfies else i am trying to return an error message.
Here is my code:
#RequestMapping(value = "/getcompanies", method = RequestMethod.POST)
public List<CompanyMaster> getCompanies(#RequestBody UserDetails user) {
String OrgLoginId = user.getOrgLoginId();
String password = user.getuPassword();
String checkLoginId = null;
String uPassword = null;
String encPassword = null;
String loginId = null;
String checkAuthorized = null;
// String loginId=userService.getLoginId(OrgLoginId);
List<Object[]> CheckIdPassword = userService.checkLoginId(OrgLoginId);
List<Object[]> results = CheckIdPassword;
for (Object[] obj : results) {
checkLoginId = obj[0].toString();
if (null == obj[1]) {
uPassword = "";
} else {
uPassword = obj[1].toString();
}
loginId = obj[2].toString();
}
checkAuthorized = loginId.substring(0, 3);
if (null != password) {
MD5 md5 = new MD5();
encPassword = md5.getPassword(password);
}
if (checkLoginId == null) {
return "Incorrect loginId..Please enter valid loginId";
} else if (encPassword.equals(uPassword)) {
if (checkAuthorized.equals("STE")) {
List<CompanyMaster> companyList = userService.getCompanyList(OrgLoginId);
return companyList;
} else {
return "You are not Authorized";
}
} else {
return "Incorrect Password";
}

Yes its possible, create a custom Exception say 'MyAppException' and throw that exception with the error message you want.
Write your logic in a try{}catch block and throw the exception in catch so that the response has the error message
public List<CompanyMaster> getCompanies(#RequestBody UserDetails user) throws MyAppppException
{
try
{
//your logic which throws error
return companyList;
}
catch( final MyAppException we )
{
throw new MyAppException("User not found", HttpStatus.NOT_FOUND);
}
}
Refer this link
https://www.codejava.net/java-core/exception/how-to-create-custom-exceptions-in-java

You can achieve this by creating a new presenter Class which contains List and status of type String and change the return type of getCompanies method to presenter class like
public CompaniesPresenter getCompanies()
And your CompaniesPresenter class should look like
public class CompaniesPresenter {
private List<CompanyMaster> companyMaster;
private string status;
//default constructor
public CompaniesPresenter(){
}
//parameterized constructor to return only string in exception case
public CompaniesPresenter(Stirng status){
this.status = status;
}
//parametirized constructor to return success case
public CompaniesPresenter(List<CompanyMaster> companyMaster, Stirng status){
this.companyMaster = companyMaster;
this.status = status;
}
//getters and setters
}
This is how your updated method lokks like
#RequestMapping(value = "/getcompanies", method = RequestMethod.POST)
public CompaniesPresenter getCompanies(#RequestBody UserDetails user) {
String OrgLoginId = user.getOrgLoginId();
String password = user.getuPassword();
String checkLoginId = null;
String uPassword = null;
String encPassword = null;
String loginId = null;
String checkAuthorized = null;
// String loginId=userService.getLoginId(OrgLoginId);
List<Object[]> CheckIdPassword = userService.checkLoginId(OrgLoginId);
List<Object[]> results = CheckIdPassword;
for (Object[] obj : results) {
checkLoginId = obj[0].toString();
if (null == obj[1]) {
uPassword = "";
} else {
uPassword = obj[1].toString();
}
loginId = obj[2].toString();
}
checkAuthorized = loginId.substring(0, 3);
if (null != password) {
MD5 md5 = new MD5();
encPassword = md5.getPassword(password);
}
if (checkLoginId == null) {
return new CompaniesPresenter("Incorrect loginId..Please enter valid loginId");
} else if (encPassword.equals(uPassword)) {
if (checkAuthorized.equals("STE")) {
List<CompanyMaster> companyList = userService.getCompanyList(OrgLoginId);
return new CompaniesPresenter(companyList,"success");
} else {
return new CompaniesPresenter("You are not Authorized");
}
} else {
return new CompaniesPresenter("Incorrect Password");
}
This is not tested please make sure for any compilation errors

vavr's Either class would be a good choice.

The usage of custom exception is most reasonable solution. However, creating custom exception for just one case is not ideal always.
Another solution is to return empty List from your method, check if the List is empty in your servlet (or wherever you are invoking this method from), and show error message there.
It seems like you want to return multiple error messages for different cases. In this case, custom exception is recommended solution. If you don't like custom exceptions, you can return List<Object> and populate error message as the first element in the list. In the place where this List is obtained, check if the first element is instanceOf String or CompanyMaster. Based on what it is, you can perform your operations. This is a weird but possible solution (only if you don't like custom exceptions).

You need to understand the problem first. You are mixing two things here, first authorization, does the user has correct privileges to get company details, second giving the company details itself. Let's understand the first problem when a user tries to access "/getcompanies" endpoint will you let him in if does not have access, in REST world your security model should take care of it. I would use spring security to achieve this. My recommendation would be to explore on "interceptor" and solve the problem of invalid user. This will make your other problem easy as your "/getcompanies" endpoint can focus only on getting the details and return it (SRP).

return any exception in json in rest api

Is there any simple methods to return exception in JSON using Rest api?
I've already googled this question, but all solutions i see, was about throwing exceptions during some calculations. But what if income parameters are wrong? I mean what if there is sone string instead of int input parameter?
I created some DTO class for input data:
#XmlRootElement
public class RequestDTO implements Serializable{
private static final long serialVersionUID = 1L;
#XmlElement(name = "request_id")
private String requestId;
#XmlElement(name = "site")
private List<String> sitesIds;
#XmlElement(name = "date_begin")
#JsonSerialize(using = DateSerializer.class)
#JsonDeserialize(using = DateDeserializer.class)
private Date dateBegin;
#XmlElement(name = "date_end")
#JsonSerialize(using = JsonDateSerializer.class)
#JsonDeserialize(using = JsonDateDeserializer.class)
private Date dateEnd;
#XmlElement(name = "volume")
private double volume;
// there is getters and setters
}
If i sent something like 'qwerty' instead of 'volume' field in my json request i'l see error message like Runtime. Is it possible to handle it in someway? I mean to return error in json with such structure?
public class ExceptionDTO {
private String shortExceptionMessage;
private String stackTrace;
public ExceptionDTO(String shotExceptionMessage, String stackTrace){
this.shortExceptionMessage = shotExceptionMessage;
this.stackTrace = stackTrace;
}
public String getShortExceptionMessage() {
return shortExceptionMessage;
}
public String getStackTrace() {
return stackTrace;
}
}
UPD1:
#Provider
#Singleton
public class ExceptionMapperProvider implements ExceptionMapper<Exception>{
#Override
public Response toResponse(final Exception e) {
StringBuilder trace = new StringBuilder();
IntStream.range(0, e.getStackTrace().length)
.forEach(i -> trace.append(e.getStackTrace()[i]).append('\n'));
ExceptionDTO exceptionMessage = new ExceptionDTO(
e.toString(),
trace.toString()
);
return Response.status(500).entity(exceptionMessage).build();
}
}

As it's not really clear if you are interested on checking if field or value of the payload is correct, here are a few ways to work with both.
If you want to check if the value for a field is correct (ie volume field value should be greater than zero etc), check out bean validation. This makes use of annotations on the fields you want to verify.
// for example
#Min(value = 0, message = "invalid message")
private double range;
To use your ExceptionDTO as error response whenever one of those validation fails, you can do so by creating an ExceptionMapper<ConstraintViolationException>. check it here for more details.
If you are checking for the invalid field (ie client sends ragne fields instead of range), have a look at the stack trace on what exception is being thrown. Then register an exception mapper with your ExceptionDTO as body.
For example, if UnrecognizedPropertyException is thrown then you can add:
#Provider
public class UnrecognizedPropertyExceptionMapper implements ExceptionMapper<UnrecognizedPropertyException> {
#Override
public Response toResponse(UnrecognizedPropertyException e) {
ExceptionDTO myDTO = // build response
return Response.status(BAD_REQUEST).entity(myDTO).build();
}
}

If you want to validate input parameters in the request, you should return status code 400 (Bad Request) along with the error details. You can simply send json
{ "error": { "message": "string received for parameter x, where as int expected" } with the response status code 400.
`

I did a bit of research and determined that the best way to encode a Java exception in JSON is to use a convention developed by Oasis that looks like this:
{
"error": {
"code": "400",
"message": "main error message here",
"target": "approx what the error came from",
"details": [
{
"code": "23-098a",
"message": "Disk drive has frozen up again. It needs to be replaced",
"target": "not sure what the target is"
}
],
"innererror": {
"trace": [ ... ],
"context": [ ... ]
}
}
}
details is a list that should have an entry for each nested cause exception in the chain.
innererror.trace should include the stack trace if you wish, as a list of string values.
The response status code should be 400 unless you have a good reason for making it something else, and the code in the structure should match whatever you sent.
Write one method to convert a Java exception to this format, and you are done. Use it consistently and your JS code will be able to handle and display the exception values.
More of the details of the other approaches evaluated and dismissed are covered in this blog post on JSON REST API – Exception Handling
https://agiletribe.purplehillsbooks.com/2015/09/16/json-rest-api-exception-handling/
Here is the java method to convert an exception to this format:
public static JSONObject convertToJSON(Exception e, String context) throws Exception {
JSONObject responseBody = new JSONObject();
JSONObject errorTag = new JSONObject();
responseBody.put("error", errorTag);
errorTag.put("code", 400);
errorTag.put("target", context);
JSONArray detailList = new JSONArray();
errorTag.put("details", detailList);
String lastMessage = "";
Throwable runner = e;
while (runner!=null) {
String className = runner.getClass().getName();
String msg = runner.toString();
runner = runner.getCause();
JSONObject detailObj = new JSONObject();
detailObj.put("message",msg);
int dotPos = className.lastIndexOf(".");
if (dotPos>0) {
className = className.substring(dotPos+1);
}
detailObj.put("code",className);
System.out.println(" ERR: "+msg);
detailList.put(detailObj);
}
JSONObject innerError = new JSONObject();
errorTag.put("innerError", innerError);
JSONArray stackList = new JSONArray();
runner = e;
while (runner != null) {
for (StackTraceElement ste : runner.getStackTrace()) {
String line = ste.getFileName() + ":" + ste.getMethodName() + ":" + ste.getLineNumber();
stackList.put(line);
}
stackList.put("----------------");
runner = runner.getCause();
}
errorTag.put("stack", stackList);
return responseBody;
}

Using AWS Java's SDKs, how can I terminate the CloudFormation stack of the current instance?

Uses on-line decomentation I come up with the following code to terminate the current EC2 Instance:
public class Ec2Utility {
static private final String LOCAL_META_DATA_ENDPOINT = "http://169.254.169.254/latest/meta-data/";
static private final String LOCAL_INSTANCE_ID_SERVICE = "instance-id";
static public void terminateMe() throws Exception {
TerminateInstancesRequest terminateRequest = new TerminateInstancesRequest().withInstanceIds(getInstanceId());
AmazonEC2 ec2 = new AmazonEC2Client();
ec2.terminateInstances(terminateRequest);
}
static public String getInstanceId() throws Exception {
//SimpleRestClient, is an internal wrapper on http client.
SimpleRestClient client = new SimpleRestClient(LOCAL_META_DATA_ENDPOINT);
HttpResponse response = client.makeRequest(METHOD.GET, LOCAL_INSTANCE_ID_SERVICE);
return IOUtils.toString(response.getEntity().getContent(), "UTF-8");
}
}
My issue is that my EC2 instance is under an AutoScalingGroup which is under a CloudFormationStack, that is because of my organisation deployment standards though this single EC2 is all there is there for this feature.
So, I want to terminate the entire CloudFormationStack from the JavaSDK, keep in mind, I don't have the CloudFormation Stack Name in advance as I didn't have the EC2 Instance Id so I will have to get it from the code using the API calls.
How can I do that, if I can do it?

you should be able to use the deleteStack method from cloud formation sdk
DeleteStackRequest request = new DeleteStackRequest();
request.setStackName(<stack_name_to_be_deleted>);
AmazonCloudFormationClient client = new AmazonCloudFormationClient (<credentials>);
client.deleteStack(request);
If you don't have the stack name, you should be able to retrieve from the Tag of your instance
DescribeInstancesRequest request =new DescribeInstancesRequest();
request.setInstanceIds(instancesList);
DescribeInstancesResult disresult = ec2.describeInstances(request);
List <Reservation> list = disresult.getReservations();
for (Reservation res:list){
List <Instance> instancelist = res.getInstances();
for (Instance instance:instancelist){
List <Tag> tags = instance.getTags();
for (Tag tag:tags){
if (tag.getKey().equals("aws:cloudformation:stack-name")) {
tag.getValue(); // name of the stack
}
}

At the end I've achieved the desired behaviour using the set of the following util functions I wrote:
/**
* Delete the CloudFormationStack with the given name.
*
* #param stackName
* #throws Exception
*/
static public void deleteCloudFormationStack(String stackName) throws Exception {
AmazonCloudFormationClient client = new AmazonCloudFormationClient();
DeleteStackRequest deleteStackRequest = new DeleteStackRequest().withStackName("");
client.deleteStack(deleteStackRequest);
}
static public String getCloudFormationStackName() throws Exception {
AmazonEC2 ec2 = new AmazonEC2Client();
String instanceId = getInstanceId();
List<Tag> tags = getEc2Tags(ec2, instanceId);
for (Tag t : tags) {
if (t.getKey().equalsIgnoreCase(TAG_KEY_STACK_NAME)) {
return t.getValue();
}
}
throw new Exception("Couldn't find stack name for instanceId:" + instanceId);
}
static private List<Tag> getEc2Tags(AmazonEC2 ec2, String instanceId) throws Exception {
DescribeInstancesRequest describeInstancesRequest = new DescribeInstancesRequest().withInstanceIds(instanceId);
DescribeInstancesResult describeInstances = ec2.describeInstances(describeInstancesRequest);
List<Reservation> reservations = describeInstances.getReservations();
if (reservations.isEmpty()) {
throw new Exception("DescribeInstances didn't returned reservation for instanceId:" + instanceId);
}
List<Instance> instances = reservations.get(0).getInstances();
if (instances.isEmpty()) {
throw new Exception("DescribeInstances didn't returned instance for instanceId:" + instanceId);
}
return instances.get(0).getTags();
}
// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
// Example of usage from the code:
deleteCloudFormationStack(getCloudFormationStackName());
// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

GWT and REST (jax-rs)

I have a project where you can ask for resources that are served by jax-rs in the json format. Everything works properly in the browser when I query the rest URL the json appears.
Now I want my GWT project to request those resources and process them and show them in my interface. The simplest way I found to do so is using a request builder and an overlay. Code is lower. The problem is, it seems when the code is running it never goes into the actual RequestCallback(). The status string is never changed. I thought it could be a SOP so I added the <add-linker name="xs"/> but still doesn't work. Any ideal?
package com.workoutcell.client;
//import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArray;
import com.google.gwt.http.client.*;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
/**
*
* #author
*/
public class RestToInfoSession{
String queryReturn = null;
JsArray<InfoJSO> arrayOfInfo = null;
String host = "http://localhost:8080/mysite";
String restModule = "/calendar/getinfo";
String id = null;
String year = null;
String month = null;
String status = "Not Initialized";
public RestToInfoSession(String id, String year, String month){
this.id =id;
this.year = year;
this.month = month;
String url = host + restModule + "/"+this.id + "/"+this.year + "/"+this.month;
RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, url);
try {
status = "Initialized at Url " + builder.getUrl();
Request request = builder.sendRequest(null, new RequestCallback() {
public void onError(Request request, Throwable exception) {
// Couldn't connect to server (could be timeout, SOP violation, etc.)
status = "Error on connecting to Server";
}
public void onResponseReceived(Request request, Response response) {
if (200 == response.getStatusCode()) {
// arrayOfInfo = jsonToJsArray(response.getText());
status = "JSON has been Fetched. Result is:" + response.getText();
} else if(0 == response.getStatusCode()) {
status = "Error is 0";
} else {
status = "Error in JSON Request:" + response.getStatusCode();
//response.getStatusText();
}
}
});
} catch (RequestException ex) {
status = "Error in Request Builder Startup";
}
}
//get an jso object in array
private final native JsArray<InfoJSO> jsonToJsArray(String json) /*-{
return eval(json);
}-*/;
public JsArray<InfoJSO> getInfoArray (){
return arrayOfInfo;
}
}
UPDATE: My problem is the same as Referring to a non-final variable data inside an inner class . I wasn't aware of asynchronous calls working mechanism. I still don't know how to pass my response.getText() to update a label that isn't part of my RestToInfoSession class any ideas?

Consider using the RestyGWT project. It will make calling JAXRS JSON resources as easy as using GWT-RPC. Plus you can typically reuse the same request response DTOs from the server side on the client side.

I have put a timer that checks every 1000ms if my json string has updated from null to the xhttp requested data. This works, but I got a feeling there is a more elegant way of resolving this problem.