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Springboot - Save entity in 'normal' class

I'm pretty new to Springboot and Java in general and because we got this in school I'm fiddeling arround.
I'm now trying to save an entity outside of the Springboot Entities, Repositories or RestController with the following code:
InfMApplication.java:
package com.domain.springboot;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import com.domain.springboot.repositories.MovieRepository;
import com.domain.springboot.services.MovieImport;
#SpringBootApplication
public class InfMApplication {
public static void main(String[] args) {
SpringApplication.run(InfMApplication.class, args);
MovieImport movieImport = new MovieImport();
movieImport.saveToDb();
}
}
MovieImport.java:
package com.domain.springboot.services;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.CrossOrigin;
import java.io.*;
import java.net.URL;
import com.google.gson.Gson;
import com.domain.omdbapi.entities.Movie;
import com.domain.omdbapi.entities.SearchResponse;
import com.domain.omdbapi.entities.SearchResult;
import com.domain.springboot.repositories.ComplexRepository;
import com.domain.springboot.repositories.DocumentRepository;
import com.domain.springboot.repositories.MovieRepository;
import com.domain.springboot.repositories.SimpleRepository;
#Service
public class MovieImport {
private final MovieRepository movieRepository;
public MovieImport(MovieRepository movieRepository){
this.movieRepository = movieRepository;
}
public void main() {
String randomImdbId = fetchRandomMovie();
Movie movie = fetchMovieDetails(randomImdbId);
saveToDb(movie);
}
public void saveToDb(Movie movie) {
com.domain.springboot.entities.Movie springbootMovie = new com.domain.springboot.entities.Movie(movie.Title, movie.imdbID);
this.movieRepository.save(springbootMovie);
}
public String fetchRandomMovie() {
String randomWord = getRandomWord();
String url = "https://www.omdbapi.com/?apikey=<API_KEY>&type=movie&s=" + randomWord;
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder(
URI.create(url))
.header("accept", "application/json")
.build();
HttpResponse<String> response = null;
try {
response = client.send(request, BodyHandlers.ofString());
} catch (Exception e) {
System.out.println(e);
}
Gson gson = new Gson();
SearchResponse searchResponse = gson.fromJson(response.body(), SearchResponse.class);
int randomIndex = new Random().nextInt(0, searchResponse.getSearch().length);
SearchResult randomResult = searchResponse.getSearch()[randomIndex];
return randomResult.getImdbID();
}
public Movie fetchMovieDetails(String imdbId) {
String url = "https://www.omdbapi.com/?apikey=<API_KEY>&type=movie&plot=full&i=" + imdbId;
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder(
URI.create(url))
.header("accept", "application/json")
.build();
HttpResponse<String> response = null;
try {
response = client.send(request, BodyHandlers.ofString());
} catch (Exception e) {
System.out.println(e);
}
Gson gson = new Gson();
Movie movie = gson.fromJson(response.body(), Movie.class);
return movie;
}
public String getRandomWord() {
URL resource = getClass().getClassLoader().getResource("Wordlist.txt");
List<String> words = new ArrayList<>();
try {
File file = new File(resource.toURI());
words = Files.readAllLines(file.toPath(), StandardCharsets.UTF_8);
} catch (Exception e) {
e.printStackTrace();
}
int randomIndex = new Random().nextInt(0, words.size());
return words.get(randomIndex);
}
}
If I use "this.movieRepository.save(movieObject);" to save a movie in the MovieRestController the same way, it works. I also tried adding the "#Autowire" annotation, but this didn't work.
I always get the error
java.lang.NullPointerException: Cannot invoke "com.domain.springboot.repositories.MovieRepository.save(Object)" because "this.movieRepository" is null
How can I get to use the movieRepository in other Java classes like in the RestControllers?

java.lang.NullPointerException: Cannot invoke
"com.domain.springboot.repositories.MovieRepository.save(Object)"
because "this.movieRepository" is null
Above is perfectly valid if we look at your following shared code.
public class MovieImport {
private MovieRepository movieRepository;
public void saveToDb() {
// Create movie
com.domain.springboot.entities.Movie springbootMovie = new com.domain.springboot.entities.Movie("Iron Man", "284cb8fgf");
this.movieRepository.save(springbootMovie);
}
}
You've to correct certain things in your code base.
First you're not initializing the movieRepository and therefore, you're getting the null pointer exception. As you've been using the springboot you can use construction injection to initialized the field by spring container. Also. this class should be scanned by spring and you should also put some annotation such as Component or Service on top of it.
Following will work if your MovieImport and MovieRepository classess will scan by springboot.
package com.domain;
import com.domain.omdbapi.entities.Movie;
import com.domain.springboot.repositories.MovieRepository;
#Service
public class MovieImport {
private final MovieRepository movieRepository;
public MovieImport(MovieRepository movieRepository){
this.movieRepository = movieRepository;
}
public void saveToDb() {
// Create movie
com.domain.springboot.entities.Movie springbootMovie = new com.domain.springboot.entities.Movie("Iron Man", "284cb8fgf");
this.movieRepository.save(springbootMovie);
}
}
Updated
#SpringBootApplication
public class InfMApplication implements CommandLineRunner {
#Autowired
private MovieImport movieImport;
public static void main(String[] args) {
SpringApplication.run(InfMApplication.class, args);
}
#Override
public void run(String... args) throws Exception {
movieImport.saveToDb();
}
}

Android MVVM architecture and observing changes on data from an API

I'm new to the Android MVVM architecture. I have an API running locally with data ("deals") in it. I'd like to simply make a request to the API and display that data in a text field. Currently the data does not show up when the fragment is first loaded, but if I go to another activity and then back to the fragment it loads.
There are 3 classes of importance here.
DashboardViewModel.java:
package com.example.android_client.ui.dashboard;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import com.example.android_client.models.Deal;
import com.example.android_client.repository.Repository;
import java.util.List;
public class DashboardViewModel extends ViewModel {
private MutableLiveData<String> mText;
private Repository repository;
private MutableLiveData<List<Deal>> deals = null;
public void init() {
if(this.deals == null) {
this.repository = Repository.getInstance();
this.deals = this.repository.getDeals();
}
}
public DashboardViewModel() {
this.mText = new MutableLiveData<>();
}
public LiveData<List<Deal>> getDeals() {
return this.deals;
}
}
DashboardFragment.java:
package com.example.android_client.ui.dashboard;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;
import com.example.android_client.R;
import com.example.android_client.models.Deal;
import java.util.List;
public class DashboardFragment extends Fragment {
private DashboardViewModel dashboardViewModel;
public View onCreateView(#NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_dashboard, container, false);
final TextView textView = root.findViewById(R.id.text_dashboard);
dashboardViewModel = ViewModelProviders.of(this).get(DashboardViewModel.class);
dashboardViewModel.init();
dashboardViewModel.getDeals().observe(this, new Observer<List<Deal>>() {
#Override
public void onChanged(List<Deal> deals) {
if (deals != null && !deals.isEmpty()) {
System.out.println(deals.get(0).toString());
textView.setText(deals.get(0).toString());
}
}
});
return root;
}
}
and Repository.java:
package com.example.android_client.repository;
import androidx.lifecycle.MutableLiveData;
import com.example.android_client.models.Deal;
import com.google.gson.Gson;
import org.jetbrains.annotations.NotNull;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;
public class Repository {
private static Repository instance;
private ArrayList<Deal> dealsList = new ArrayList<>();
private final OkHttpClient client = new OkHttpClient();
public static Repository getInstance() {
if(instance == null) {
instance = new Repository();
}
return instance;
}
private Repository() {}
public MutableLiveData<List<Deal>> getDeals() {
setDeals();
MutableLiveData<List<Deal>> deals = new MutableLiveData<>();
deals.setValue(dealsList);
return deals;
}
private void setDeals() {
Request request = new Request.Builder()
.url("http://10.0.2.2:8000/api/deals?<params here>")
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(#NotNull Call call, #NotNull IOException e) {
e.printStackTrace();
}
#Override
public void onResponse(#NotNull Call call, #NotNull Response response) throws IOException {
try (ResponseBody responseBody = response.body()) {
if (!response.isSuccessful()) {
throw new IOException("Unexpected code " + response);
}
String jsonDeals = responseBody.string(); // can only call string() once or you'll get an IllegalStateException
Deal[] deals = new Gson().fromJson(jsonDeals, Deal[].class);
dealsList = new ArrayList<>(Arrays.asList(deals));
}
}
});
}
}
When stepping through the code in the Repository class I can see that setDeals() is called when I load the fragment, and the request in the callback is queued. The first time getDeals() returns, it returns a list of 0 deals (within the MutableLiveData object).
onResponse in the callback doesn't run until the fragment is already loaded. When debugging I can see that the data is in the objects (all the Gson stuff works fine), but onChanged doesn't get called again (which sets the text view).
Am I not observing changes on the deals properly?

Your code is not working due to a new live data instance be created whenever getDeals() is called and the api response value be informed to other live data instance. You must set api response value to same instance of MutableLiveData returned by getDeals()
I'm not saying that it is the best architectural solution, but if you create a mutable live data as a class attribute and return it whenever getDeals() is called. Probably, it's going to work.
Also, a good practice is return a LiveData and not a MutableLiveData to not allowing a external component modify the internal value.
Please, take a look at the piece of code below.
OBS: Maybe, there is some syntax error, because I have not compiled it
import com.example.android_client.models.Deal;
import com.google.gson.Gson;
import org.jetbrains.annotations.NotNull;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;
public class Repository {
private static Repository instance;
private ArrayList<Deal> dealsList = new ArrayList<>();
private final OkHttpClient client = new OkHttpClient();
private MutableLiveData<List<Deal>> _deals = new MutableLiveData<>();
private LiveData<List<Deal>> deals = _deals
public static Repository getInstance() {
if(instance == null) {
instance = new Repository();
}
return instance;
}
private Repository() {}
public LiveData<List<Deal>> getDeals() {
setDeals();
return deals;
}
private void setDeals() {
Request request = new Request.Builder()
.url("http://10.0.2.2:8000/api/deals?<params here>")
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(#NotNull Call call, #NotNull IOException e) {
e.printStackTrace();
}
#Override
public void onResponse(#NotNull Call call, #NotNull Response response) throws IOException {
try (ResponseBody responseBody = response.body()) {
if (!response.isSuccessful()) {
throw new IOException("Unexpected code " + response);
}
String jsonDeals = responseBody.string(); // can only call string() once or you'll get an IllegalStateException
Deal[] deals = new Gson().fromJson(jsonDeals, Deal[].class);
dealsList = new ArrayList<>(Arrays.asList(deals));
_deals.setValue(dealsList);
}
}
});
}
}
When

I think this would help. Try postValue on MutableLiveData in onResponse of network call. Please change your repository class like below:
package com.example.android_client.repository;
import androidx.lifecycle.MutableLiveData;
import com.example.android_client.models.Deal;
import com.google.gson.Gson;
import org.jetbrains.annotations.NotNull;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;
public class Repository {
private static Repository instance;
private ArrayList<Deal> dealsList = new ArrayList<>();
private final OkHttpClient client = new OkHttpClient();
MutableLiveData<List<Deal>> deals = new MutableLiveData<>();
public static Repository getInstance() {
if(instance == null) {
instance = new Repository();
}
return instance;
}
private Repository() {}
private MutableLiveData<List<Deal>> getDeals() {
Request request = new Request.Builder()
.url("http://10.0.2.2:8000/api/deals?<params here>")
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(#NotNull Call call, #NotNull IOException e) {
e.printStackTrace();
}
#Override
public void onResponse(#NotNull Call call, #NotNull Response response) throws IOException {
try (ResponseBody responseBody = response.body()) {
if (!response.isSuccessful()) {
throw new IOException("Unexpected code " + response);
}
String jsonDeals = responseBody.string(); // can only call string() once or you'll get an IllegalStateException
Deal[] deals = new Gson().fromJson(jsonDeals, Deal[].class);
dealsList = new ArrayList<>(Arrays.asList(deals));
deals.postValue(dealsList);
}
}
});
return deals;
}
}

in your repository class in function get deals. you are initializing live data. requesting url in background thread and posting value on live data which is not received from server yet.
to solve this create livedata instance in constructor of repository and postvalue on livedata in onResponse callback.
//sorry for bad writting, posted from mobile.

Spring Boot Autowired Repository null [duplicate]

This question already has answers here:
Why is my Spring #Autowired field null?
(21 answers)
Closed 3 years ago.
I am creating a Netty UDP server using the spring framework. I have 3 classes and 1 interface.
UDPServer.java
package com.example.nettyUDPserver;
import java.net.InetAddress;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.stereotype.Component;
import akka.actor.ActorRef;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioDatagramChannel;
public class UDPServer {
private int port;
ActorRef serverActor = null;
public UDPServer(int port) {
this.port = port;
}
public void run() throws Exception {
final NioEventLoopGroup group = new NioEventLoopGroup();
try {
final Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioDatagramChannel.class)
.option(ChannelOption.SO_BROADCAST, true)
.handler(new ChannelInitializer<NioDatagramChannel>() {
#Override
public void initChannel(final NioDatagramChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast(new IncomingPacketHandler());
}
});
Integer pPort = port;
InetAddress address = InetAddress.getLocalHost();
//InetAddress address = InetAddress.getByName("192.168.1.53");
System.out.println("Localhost address is: " + address.toString());
b.bind(address, pPort).sync().channel().closeFuture().await();
} finally {
group.shutdownGracefully().sync();
}
}
public static void main(String[] args) throws Exception {
int port = 6001;
new UDPServer(port).run();
}
}
IncomingPacketHandler.java
package com.example.nettyUDPserver;
import java.net.InetAddress;
import java.nio.charset.StandardCharsets;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Component;
import com.example.dao.SensorRepository;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.DatagramPacket;
#ComponentScan("com.example.dao")
public class IncomingPacketHandler extends SimpleChannelInboundHandler<DatagramPacket> {
#Autowired
SensorRepository repo;
IncomingPacketHandler(){
}
#Override
protected void channelRead0(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception {
final InetAddress srcAddr = packet.sender().getAddress();
ByteBuf buffer = packet.content();
packet.replace(buffer);
int len = buffer.readableBytes();
byte[] message = new byte[len];
buffer.readBytes(message);
String str = new String(message, StandardCharsets.UTF_8);
ObjectMapper mapper = new ObjectMapper();
JsonNode actualObj = mapper.readTree(str);
int id = actualObj.get("sensor_id").asInt();
String status = actualObj.get("status").asText();
System.out.println("==========================================================");
System.out.println("Source address of datagram received: " + srcAddr.toString());
System.out.println("String message received: " + str);
show();
}
public void show() {
System.out.println("In show function, we will perform our CRUD operations");
System.out.println(repo);
// try {
// this.repo.findAll().forEach(x -> System.out.println(x));
// } catch (NullPointerException e) {
// e.printStackTrace();
// }
}
}
Sensor.java
package com.example.models;
import javax.persistence.Entity;
import javax.persistence.Id;
#Entity
public class Sensor {
#Id
private int sensor_id;
private String status;
private double batLev;
public int getSensor_id() {
return sensor_id;
}
public void setSensor_id(int sensor_id) {
this.sensor_id = sensor_id;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public double getBatLev() {
return batLev;
}
public void setBatLev(double batLev) {
this.batLev = batLev;
}
}
SensorRepository.java
package com.example.dao;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.example.models.Sensor;
#Repository
public interface SensorRepository extends CrudRepository<Sensor, Integer> {
}
I am running my server in the class UDPServer.java and I can successfully get and decode datagrams. The problem is with the SensorRepository in the IncomingPacketHandler.java class. I am using the #Autowired notation in the variable and I am using the #Repository annotation in the interface, but when I print the value of the autowired repository, it is null, so I cannot make SQL queries. Any ideas?
UPDATE
Thank you for your answers guys, much appreciated. I am denoting the IncomingPacketHandler class as a component and I am autowiring it in the UDPServer class. When I run it I get this:
[nioEventLoopGroup-2-1] DEBUG io.netty.channel.DefaultChannelPipeline - Discarded inbound message DatagramPacket(/192.168.61.64:59905 => /192.168.61.64:6001, PooledUnsafeDirectByteBuf(ridx: 0, widx: 38, cap: 2048)) that reached at the tail of the pipeline. Please check your pipeline configuration.
This is probably out of the scope of this question, but you maybe can show me tha direction. Thank you once again.

Your class IncomingPacketHandler is not managed by Spring, but created by you personally:
ChannelPipeline p = ch.pipeline();
p.addLast(new IncomingPacketHandler());
As such, even if you add a million Spring annotations, they won't do anything. What you want instead is to have Spring create this handler, and pass the Spring-created handler as argument to p.addLast

The IncomingPacketHandler class has been created manually and not by Spring and hence bean is not available.
Add #Component to IncomingPacketHandler class:
...
import org.springframework.stereotype.Component;
#Component
public class IncomingPacketHandler extends
...
And then in UDPServer.java:
...
import org.springframework.beans.factory.annotation.Autowired;
#Component
public class UDPServer {
#Autowired
private IncomingPacketHandler incomingPacketHandler;
...

How to correctly implement CORS in WebFlux?

I want to create a simple Spring Boot/Webflux server to serve as REST API. I'm trying to test it currently locally. The Webflux server is running on port 8080 and I have another server serving the html (React.js) running on port 3000. I want to make a CORS request from the website to the server. To that end I created a Java class with a method addCorsMappings and added #Configuration annotation. I was wondering if adding an annotation magically make Spring aware of the annotated class but according to this article I also need to add org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.mypackage.CORSHandler property in spring.factories file which I did. However I still see that addCorsMappings is not even called (I don't see log message). Being new to Spring Boot is there any other configuration I'm missing?
This is my main class:
package com.mypackage;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import reactor.ipc.netty.http.server.HttpServer;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.reactive.HttpHandler;
import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerResponse;
import static org.springframework.http.HttpStatus.UNAUTHORIZED;
import static org.springframework.http.MediaType.APPLICATION_JSON;
import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
import static org.springframework.web.reactive.function.server.RequestPredicates.contentType;
import static org.springframework.web.reactive.function.server.RequestPredicates.method;
import static org.springframework.web.reactive.function.server.RequestPredicates.path;
import static org.springframework.web.reactive.function.server.RouterFunctions.nest;
import static org.springframework.web.reactive.function.server.RouterFunctions.route;
import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
public class Server {
private static final Logger log = LogManager.getLogger(Server.class);
public static final String HOST = "localhost";
public static final int PORT = 8080;
public static void main(String[] args) throws Exception {
Server server = new Server();
server.startReactorServer();
System.out.println("Press ENTER to exit.");
System.in.read();
}
public RouterFunction<ServerResponse> routingFunction() {
PersonRepository repository = new DummyPersonRepository();
PersonHandler handler = new PersonHandler(repository);
return nest(path("/person"),
nest(accept(APPLICATION_JSON),
route(GET("/{id}"), handler::getPerson)
.andRoute(method(HttpMethod.GET), handler::listPeople)
).andRoute(POST("/").and(contentType(APPLICATION_JSON)), handler::createPerson));
}
public void startReactorServer() {
RouterFunction<ServerResponse> route = routingFunction().filter((request, next) -> {
log.warn(request.path());
if (request.path().contains("person")) {
log.warn("calling next()");
return next.handle(request);
} else {
return ServerResponse.status(UNAUTHORIZED).build();
}
});
HttpHandler httpHandler = toHttpHandler(route);
ReactorHttpHandlerAdapter adapter = new ReactorHttpHandlerAdapter(httpHandler);
HttpServer server = HttpServer.create(HOST, PORT);
server.newHandler(adapter).block();
}
}
and this is my CORSHandler class:
package com.mypackage;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.boot.autoconfigure.AutoConfigureOrder;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.web.reactive.config.CorsRegistry;
import org.springframework.web.reactive.config.EnableWebFlux;
import org.springframework.web.reactive.config.WebFluxConfigurer;
import org.springframework.web.reactive.function.server.HandlerFunction;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
#Configuration
public class CORSHandler implements WebFluxConfigurer {
private static final Logger log = LogManager.getLogger(CORSHandler.class);
#Override
public void addCorsMappings(CorsRegistry registry) {
log.warn("from addCorsMappings!!");
registry.addMapping("*")
.allowedOrigins("*")
.allowedMethods("*")
.allowedHeaders("Content-Type", "Access-Control-Allow-Headers", "Authorization",
"X-Requested-With", "mode")
.allowCredentials(true);
}
}

The solution I currently found is that The class which contains configuration methods needs to be given as a parameter to AnnotationConfigApplicationContext context. The context needs to be given as a parameter to WebHttpHandlerBuilder.webHandler(RouterFunctions.toWebHandler(route)).applicationContext(context). So the main class would look like this:
package com.mypackage;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.web.reactive.function.server.RouterFunctions;
import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
import reactor.ipc.netty.http.server.HttpServer;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.reactive.HttpHandler;
import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerResponse;
import static org.springframework.http.HttpStatus.UNAUTHORIZED;
import static org.springframework.http.MediaType.APPLICATION_JSON;
import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
import static org.springframework.web.reactive.function.server.RequestPredicates.contentType;
import static org.springframework.web.reactive.function.server.RequestPredicates.method;
import static org.springframework.web.reactive.function.server.RequestPredicates.path;
import static org.springframework.web.reactive.function.server.RouterFunctions.nest;
import static org.springframework.web.reactive.function.server.RouterFunctions.route;
import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
#SpringBootApplication
public class Server {
private static final Logger log = LogManager.getLogger(Server.class);
public static final String HOST = "localhost";
public static final int PORT = 8080;
public static void main(String[] args) throws Exception {
AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(CorsConfiguration.class);
Server server = new Server();
server.startReactorServer(ctx);
System.out.println("Press ENTER to exit.");
System.in.read();
}
public RouterFunction<ServerResponse> routingFunction() {
PersonRepository repository = new DummyPersonRepository();
PersonHandler handler = new PersonHandler(repository);
return nest(path("/person"),
nest(accept(APPLICATION_JSON),
route(GET("/{id}"), handler::getPerson)
.andRoute(method(HttpMethod.GET), handler::listPeople)
).andRoute(POST("/").and(contentType(APPLICATION_JSON)), handler::createPerson));
}
public void startReactorServer(AnnotationConfigApplicationContext ctx) {
RouterFunction<ServerResponse> route = this.routingFunction().filter((request, next) -> {
log.warn(request.path());
if (request.path().contains("person")) {
log.warn("calling next()");
return next.handle(request);
} else {
return ServerResponse.status(UNAUTHORIZED).build();
}
});
HttpHandler httpHandler = WebHttpHandlerBuilder.webHandler(RouterFunctions.toWebHandler(route))
.applicationContext(ctx).build();
ReactorHttpHandlerAdapter adapter = new ReactorHttpHandlerAdapter(httpHandler);
HttpServer server = HttpServer.create(HOST, PORT);
server.newHandler(adapter).block();
}
}
and CorsConfiguration class would look like this:
package com.mypackage;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.reactive.config.EnableWebFlux;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;
#Configuration
#EnableWebFlux
public class CorsConfiguration {
private static final Logger log = LogManager.getLogger(CorsConfiguration.class);
private static final String ALLOWED_HEADERS = "x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN, mode";
private static final String ALLOWED_METHODS = "GET, PUT, POST, DELETE, OPTIONS";
private static final String ALLOWED_ORIGIN = "*";
private static final String MAX_AGE = "3600";
#Bean
public WebFilter corsFilter() {
log.warn("from CorsConfiguration!!!");
return (ServerWebExchange ctx, WebFilterChain chain) -> {
ServerHttpRequest request = ctx.getRequest();
log.warn("after ServerHttpRequest");
if (CorsUtils.isCorsRequest(request)) {
log.warn("inside isCorsRequest");
ServerHttpResponse response = ctx.getResponse();
HttpHeaders headers = response.getHeaders();
headers.add("Access-Control-Allow-Origin", ALLOWED_ORIGIN);
headers.add("Access-Control-Allow-Methods", ALLOWED_METHODS);
headers.add("Access-Control-Max-Age", MAX_AGE);
headers.add("Access-Control-Allow-Headers", ALLOWED_HEADERS);
if (request.getMethod() == HttpMethod.OPTIONS) {
response.setStatusCode(HttpStatus.OK);
return Mono.empty();
}
}
return chain.filter(ctx);
};
}
}
In this code corsFilter is called and sets the CORS headers but routing doesn't work however (404 status is returned).

Get attribute from Restful XML without tags in client

I want to get the attribute value from XML output that is being created by my Rest Web Service but without the tags in my Java client. I tried XPath but it doesn't seem to work with URLs, only with XML files that are stored in the drive. And all the answers about XPath are specifically for stored XML files not online. I am using Netbeans. The concept is, web service takes two numbers and provides the sum as an XML. Webservice url that I use in this example http://localhost:8080/WSDemo/rest/book/5/2
Rest Web service
ApplicationConfig.java
package wbs;
import java.util.Set;
import javax.ws.rs.core.Application;
import javax.xml.bind.annotation.XmlRootElement;
#javax.ws.rs.ApplicationPath("rest")
public class ApplicationConfig extends Application {
#Override
public Set<Class<?>> getClasses() {
Set<Class<?>> resources = new java.util.HashSet<>();
addRestResourceClasses(resources);
return resources;
}
private void addRestResourceClasses(Set<Class<?>> resources) {
resources.add(wbs.GenericResource.class);
}
}
GenericResource.java
package wbs;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.Produces;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.MediaType;
import javax.xml.bind.annotation.XmlRootElement;
#Path("book")
public class GenericResource {
#Context
private UriInfo context;
#GET
#Produces(MediaType.APPLICATION_XML)
#Path("{n1}/{n2}")
public String getSum(#PathParam ("n1") int a, #PathParam ("n2") int b) {
int c = a+b;
return "<Sum>" + c + "</Sum>";
}
}
Client
Sum.java
package restclient;
import javax.ws.rs.ClientErrorException;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.WebTarget;
public class Sum {
private WebTarget webTarget;
private Client client;
private static final String BASE_URI = "http://localhost:8080/WSDemo/rest/";
public Sum(){
client = javax.ws.rs.client.ClientBuilder.newClient();
webTarget = client.target(BASE_URI).path("book");
}
public <T> T getSum(Class<T> responseType, String n1, String n2) throws ClientErrorException {
WebTarget resource = webTarget;
resource = resource.path(java.text.MessageFormat.format("{0}/{1}", new Object[]{n1, n2}));
return resource.request(javax.ws.rs.core.MediaType.APPLICATION_XML).get(responseType);
}
public void putXml(Object requestEntity) throws ClientErrorException {
webTarget.request(javax.ws.rs.core.MediaType.APPLICATION_XML).put(javax.ws.rs.client.Entity.entity(requestEntity, javax.ws.rs.core.MediaType.APPLICATION_XML));
}
public void close() {
client.close();
}
}
RestClient.java
package com.emmanouil;
import restclient.Sum;
public class RestClient {
public static void main(String[] args) {
Sum client = new Sum();
String response = client.getSum (String.class,"5" , "2");
System.out.println(response);
client.close();
}
}
Output
I want to clear the tags and get the result (7 in this case). Of course, I can trim the string or any other other similar way but it's something that I don't want to do.