Added first working prototype.

src/main/java/nl/andrewl/railsignalapi/RailSignalApiApplication.java

@@ -7,6 +7,7 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 public class RailSignalApiApplication {
 
 	public static void main(String[] args) {
+		System.setProperty("org.apache.tomcat.websocket.DISABLE_BUILTIN_EXTENSIONS", "true");
 		SpringApplication.run(RailSignalApiApplication.class, args);
 	}
 

src/main/java/nl/andrewl/railsignalapi/dao/SignalRepository.java

@@ -13,10 +13,13 @@ import java.util.Optional;
 @Repository
 public interface SignalRepository extends JpaRepository<Signal, Long> {
 	Optional<Signal> findByIdAndRailSystem(long id, RailSystem railSystem);
+	Optional<Signal> findByIdAndRailSystemId(long id, long railSystemId);
 	boolean existsByNameAndRailSystem(String name, RailSystem railSystem);
 
 	@Query("SELECT DISTINCT s FROM Signal s " +
 			"LEFT JOIN s.branchConnections bc " +
 			"WHERE bc.branch = :branch")
 	List<Signal> findAllConnectedToBranch(Branch branch);
+
+	List<Signal> findAllByRailSystemOrderByName(RailSystem railSystem);
 }

src/main/java/nl/andrewl/railsignalapi/rest/SignalsApiController.java

@@ -6,6 +6,8 @@ import nl.andrewl.railsignalapi.rest.dto.SignalResponse;
 import nl.andrewl.railsignalapi.service.SignalService;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.List;
+
 @RestController
 @RequestMapping(path = "/api/railSystems/{rsId}/signals")
 @RequiredArgsConstructor
@@ -16,4 +18,14 @@ public class SignalsApiController {
 	public SignalResponse createSignal(@PathVariable long rsId, @RequestBody SignalCreationPayload payload) {
 		return signalService.createSignal(rsId, payload);
 	}
+
+	@GetMapping
+	public List<SignalResponse> getSignals(@PathVariable long rsId) {
+		return signalService.getAllSignals(rsId);
+	}
+
+	@GetMapping(path = "/{sigId}")
+	public SignalResponse getSignal(@PathVariable long rsId, @PathVariable long sigId) {
+		return signalService.getSignal(rsId, sigId);
+	}
 }

src/main/java/nl/andrewl/railsignalapi/rest/dto/SignalResponse.java

@@ -3,6 +3,7 @@ package nl.andrewl.railsignalapi.rest.dto;
 import nl.andrewl.railsignalapi.model.Signal;
 import nl.andrewl.railsignalapi.model.SignalBranchConnection;
 
+import java.util.Comparator;
 import java.util.List;
 
 public record SignalResponse(
@@ -15,6 +16,7 @@ public record SignalResponse(
 				signal.getId(),
 				signal.getName(),
 				signal.getBranchConnections().stream()
+						.sorted(Comparator.comparing(SignalBranchConnection::getDirection))
 						.map(ConnectionData::new)
 						.toList()
 		);

src/main/java/nl/andrewl/railsignalapi/service/SignalService.java

@@ -22,10 +22,7 @@ import org.springframework.web.socket.WebSocketMessage;
 import org.springframework.web.socket.WebSocketSession;
 
 import java.io.IOException;
-import java.util.HashSet;
+import java.util.*;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 @Service
@@ -93,12 +90,14 @@ public class SignalService {
 			log.warn("Warning! Train is entering a non-free branch {}.", toBranch.getName());
 		}
 		if (toBranch.getStatus() != BranchStatus.OCCUPIED) {
+			log.info("Updating branch {} status from {} to {}.", toBranch.getName(), toBranch.getStatus(), BranchStatus.OCCUPIED);
 			toBranch.setStatus(BranchStatus.OCCUPIED);
 			branchRepository.save(toBranch);
 			broadcastToConnectedSignals(toBranch);
 		}
 		if (updateType == SignalUpdateType.END) {
 			if (fromBranch.getStatus() != BranchStatus.FREE) {
+				log.info("Updating branch {} status from {} to {}.", fromBranch.getName(), fromBranch.getStatus(), BranchStatus.FREE);
 				fromBranch.setStatus(BranchStatus.FREE);
 				branchRepository.save(fromBranch);
 				broadcastToConnectedSignals(fromBranch);
@@ -125,4 +124,20 @@ public class SignalService {
 		}
 
 	}
+
+	@Transactional(readOnly = true)
+	public SignalResponse getSignal(long rsId, long sigId) {
+		var s = signalRepository.findByIdAndRailSystemId(sigId, rsId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		return new SignalResponse(s);
+	}
+
+	@Transactional(readOnly = true)
+	public List<SignalResponse> getAllSignals(long rsId) {
+		var rs = railSystemRepository.findById(rsId)
+						.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Rail system not found."));
+		return signalRepository.findAllByRailSystemOrderByName(rs).stream()
+				.map(SignalResponse::new)
+				.toList();
+	}
 }