Jersey Response for Exception not working as Expected - jersey

Question

I am authenticating user with name and password from my database.
If the user name or password is incorrect then I am throwing a custom Exception.
but I am not getting expected status code and response.
I am new to Jersey and web services.
This is my function which creates a response :
public static Response error(int Status_code, String Request_status ,String data, String Response_error){
ResponseBuilder response = new ResponseBuilder();
response.Status_code = Status_code;
response.Request_status = Request_status;
response.data =data;
response.Response_error = Response_error;
return Response.status(Status_code).entity(response).build();
}
This is my custom Exception class code :
public class InvalidcredentialsException extends WebApplicationException {
public InvalidcredentialsException(Response response ) {
super(response);
}
}
This is how I am throwing this exception in my code if credentials are wrong(user name and password) in AuthenticateUser function in my Model.
throw new InvalidcredentialsException(ResponseBuilder.error(Response.Status.UNAUTHORIZED.getStatusCode(),"success","","invalid credentials"));
When I am checking my API I am getting 204 as response , but I am expecting a JSON with the parameters which I have provided.
I have implemented my API in the following way :
#Path("/user")
public class User {
#POST
#Path("/login")
#Consumes(MediaType.APPLICATION_JSON)
#Produces("application/json")
public void UserAuthentication(UserCredentials user) {
UserModel userAuthentication = new UserModel();
userAuthentication.AuthenticateUser(user);
}
}
I have used the following link to create Exception and throw :
JAX-RS / Jersey how to customize error handling?
This is my authenticate function :
public void AuthenticateUser(UserCredentials user) {
Database db = new Database();
Connection con = null;
PreparedStatement preparedStatement = null;
ResultSet rs = null;
try {
String username = user.getUsername();
String password = user.getPassword();
con = db.getConnection();
if (con != null) {
String selectQuery_UserDetails = "SELECT name,password FROM user WHERE name=? AND password = ?";
preparedStatement = con.prepareStatement(selectQuery_UserDetails);
preparedStatement.setString(1, username);
preparedStatement.setString(2, password);
rs = preparedStatement.executeQuery();
if (!rs.isBeforeFirst()) {
throw new InvalidcredentialsException(ResponseBuilder.error(Response.Status.UNAUTHORIZED.getStatusCode(),"success","","invalid credentials"));
}
}}catch (SQLException e) {
} finally {
db.closeConnection(con);
}
}
Thanks

Answer 1

You are catching but not handling the SQLException. When an error occurs, while accessing or trying to access the database, the exception is ignored and no error response is created. Maybe the database is not accessible or configured incorrectly.
You should wrap the exception into a RuntimeException like javax.ws.rs.InternalServerErrorException or just remove the catch statement. And you should log the error here or in an exception mapper, so that you are able to analyze and fix the problem.
I suggest to wrap the exception and log it like that:
}catch(SQLException e){
logger.log(Level.SEVERE, "db error while authenticate user", e);
throw new InternalServerErrorException("db error while authenticate user", e);
}
Now the runtime exception will be handled by a default exception mapper, which will generate the error response. Additional the error is logged. In this code I used java.util.logging - if necessary adjust it to the logging api you use.