Initial check in

2021-10-23 18:48:50 +05:30
parent e4d52aa182
commit f46c7c7fa3
5 changed files with 372 additions and 0 deletions
--- a/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/SpringbootResilience4jApplication.java
+++ b/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/SpringbootResilience4jApplication.java
@@ -14,6 +14,9 @@ public class SpringbootResilience4jApplication {
 	@Autowired
 	private RateLimiterExamplesRunner rateLimiterExamplesRunner;

+	@Autowired
+	private TimeLimiterExamplesRunner timeLimiterExamplesRunner;
+
 	public static void main(String[] args) {
 		SpringApplication.run(SpringbootResilience4jApplication.class, args);
 	}
@@ -22,5 +25,6 @@ public class SpringbootResilience4jApplication {
 	public void runExamples() {
 		retryExamplesRunner.run();
 		rateLimiterExamplesRunner.run();
+		timeLimiterExamplesRunner.run();
 	}
 }
--- a/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimiterExamplesRunner.java
+++ b/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimiterExamplesRunner.java
@@ -0,0 +1,142 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.reflectoring.resilience4j.springboot.model.Flight;
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class TimeLimiterExamplesRunner {
+
+  @Autowired
+  private TimeLimitingService service;
+
+  private DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss SSS");
+
+  public static void main(String[] args) {
+    TimeLimiterExamplesRunner runner = new TimeLimiterExamplesRunner();
+    runner.run();
+  }
+
+  static void delay(int seconds) {
+    // sleep to simulate delay
+    try {
+      Thread.sleep(seconds * 1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+  }
+
+  public void run() {
+    System.out.println("Running timelimiter examples");
+
+    System.out.println(
+        "----------------------- basicExample ----------------------------------------------------");
+    basicExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println(
+        "----------------------------------------------------------------------------------------------------");
+
+    System.out.println("----------------------- timeoutExample ----------------------------------------------");
+    timeoutExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println("----------------------------------------------------------------------------------------------------");
+
+    System.out.println("----------------------- fallbackExample ----------------------------------------------");
+    fallbackExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println("----------------------------------------------------------------------------------------------------");
+
+    System.out.println(
+        "----------------------- eventsExample ----------------------------------------------------");
+    eventsExample();
+    delay(10); // delay just to let the above async operation to complete
+    System.out.println(
+        "----------------------------------------------------------------------------------------------------");
+  }
+
+  private void eventsExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    for (int i = 0; i < 10; i++) {
+      int attempt = i;
+      service.eventsExample(request)
+          .whenComplete((r, t) -> {
+            if (t != null) {
+              System.out.println("Error occurred on search " + attempt + ": " + t.getMessage());
+            }
+            if (r != null) {
+              System.out
+                  .println("Search " + attempt + " successful, found " + r.size() + " flights");
+            }
+          });
+    }
+  }
+
+  private void timeoutExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.timeoutExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+        ex.printStackTrace();
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+
+  private void basicExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.basicExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+
+  private void fallbackExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.fallbackExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+}
--- a/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimitingService.java
+++ b/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimitingService.java
@@ -0,0 +1,167 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.github.resilience4j.micrometer.tagged.TaggedTimeLimiterMetrics;
+import io.github.resilience4j.ratelimiter.RequestNotPermitted;
+import io.github.resilience4j.ratelimiter.annotation.RateLimiter;
+import io.github.resilience4j.timelimiter.TimeLimiter.EventPublisher;
+import io.github.resilience4j.timelimiter.TimeLimiterConfig;
+import io.github.resilience4j.timelimiter.TimeLimiterRegistry;
+import io.github.resilience4j.timelimiter.annotation.TimeLimiter;
+import io.micrometer.core.instrument.Measurement;
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import io.reflectoring.resilience4j.springboot.model.Flight;
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import io.reflectoring.resilience4j.springboot.services.FlightSearchService;
+import java.sql.Time;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.stream.StreamSupport;
+import javax.annotation.PostConstruct;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class TimeLimitingService {
+  @Autowired
+  private FlightSearchService remoteSearchService;
+
+  @Autowired
+  private TimeLimiterRegistry timeLimiterRegistry;
+
+/*
+  void printDefaultValues() {
+    TimeLimiterConfig config = TimeLimiterConfig.ofDefaults();
+
+    System.out.println(
+        "getTimeoutDuration in ms = " + Duration.from(config.getTimeoutDuration()).toMillis());
+    System.out.println("shouldCancelRunningFuture = " + config.shouldCancelRunningFuture());
+  } */
+
+
+  @TimeLimiter(name = "basicExample")
+  CompletableFuture<List<Flight>> basicExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  @TimeLimiter(name = "timeoutExample")
+  CompletableFuture<List<Flight>> timeoutExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  @TimeLimiter(name = "timeAndRateLimiter")
+  @RateLimiter(name = "timeAndRateLimiter")
+  CompletableFuture<List<Flight>> aspectOrderExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  /*
+  void basicExample_ExcecuteCompletionStage() {
+    TimeLimiterConfig config = TimeLimiterConfig.custom()
+        .timeoutDuration(Duration.ofMillis(500))
+        .build();
+
+    TimeLimiterRegistry registry = TimeLimiterRegistry.of(config);
+    TimeLimiter limiter = registry.timeLimiter("flightSearch");
+
+    FlightSearchService service = new FlightSearchService();
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/30/2020");
+
+    Supplier<List<Flight>> flightSupplier = () -> service.searchFlightsTakingOneSecond(request);
+    Supplier<CompletionStage<List<Flight>>> origCompletionStageSupplier = () -> CompletableFuture
+        .supplyAsync(flightSupplier);
+    ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
+    CompletionStage<List<Flight>> decoratedCompletionStage = limiter
+        .executeCompletionStage(scheduler, origCompletionStageSupplier);
+
+    decoratedCompletionStage.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+
+    scheduler.shutdown();
+  }
+
+
+  void whenToUseExample() {
+    CompletableFuture.supplyAsync(this::slowMethod).thenAccept(System.out::println);
+  }
+
+  void whenToUseExample_Blocking()
+      throws InterruptedException, ExecutionException, TimeoutException {
+    CompletableFuture<Integer> completableFuture = CompletableFuture
+        .supplyAsync(this::slowMethod);
+    Integer result = completableFuture.get(3000, TimeUnit.MILLISECONDS);
+    System.out.println(result);
+  }
+
+  int slowMethod() {
+    System.out.println(Thread.currentThread().getName());
+    // sleep to simulate delay
+    try {
+      Thread.sleep(2000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+    return 0;
+  }
+
+  static void delay(int seconds) {
+    // sleep to simulate delay
+    try {
+      Thread.sleep(seconds * 1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+  } */
+
+  @TimeLimiter(name = "eventsExample")
+  CompletableFuture<List<Flight>>  eventsExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingRandomTime(request));
+  }
+
+  @TimeLimiter(name = "fallbackExample", fallbackMethod = "localCacheFlightSearch")
+  CompletableFuture<List<Flight>> fallbackExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  private CompletableFuture<List<Flight>> localCacheFlightSearch(SearchRequest request, TimeoutException rnp) {
+    System.out.println("Returning search results from cache");
+    System.out.println(rnp.getMessage());
+    CompletableFuture<List<Flight>> result = new CompletableFuture<>();
+    result.complete(Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 781", request.getFlightDate(), request.getFrom(), request.getTo())));
+    return result;
+  }
+
+  @PostConstruct
+  void postConstruct() {
+    EventPublisher eventPublisher = timeLimiterRegistry.timeLimiter("eventsExample").getEventPublisher();
+    eventPublisher.onSuccess(System.out::println);
+    eventPublisher.onError(System.out::println);
+    eventPublisher.onTimeout(System.out::println);
+  }
+}
--- a/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/services/FlightSearchService.java
+++ b/resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/services/FlightSearchService.java
@@ -13,6 +13,7 @@ import java.time.format.DateTimeFormatter;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Random;
 import org.springframework.stereotype.Service;

@Service
@@ -20,6 +21,7 @@ public class FlightSearchService {

  PotentialFailure potentialFailure = new NoFailure();
  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss SSS");
+  Random random = new Random();

  PotentialFailureCheckedException potentialFailureCheckedException = new NoCheckedExceptionFailure();

@@ -108,4 +110,42 @@ public class FlightSearchService {
    response.setFlights(flights);
    return response;
  }
+
+  public List<Flight> searchFlightsTakingOneSecond(SearchRequest request) {
+    System.out.println("Searching for flights; "
+        + "current time = " + LocalDateTime.now().format(formatter) +
+        "; current thread = " + Thread.currentThread().getName());
+
+    try {
+      Thread.sleep(1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+
+    List<Flight> flights = Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 746", request.getFlightDate(), request.getFrom(), request.getTo())
+    );
+    System.out.println("Flight search successful at " + LocalDateTime.now().format(formatter));
+    return flights;
+  }
+
+  public List<Flight> searchFlightsTakingRandomTime(SearchRequest request) {
+    long delay = random.nextInt(3000);
+    try {
+      Thread.sleep(delay);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+    System.out.println("Searching for flights; "
+        + "current time = " + LocalDateTime.now().format(formatter) +
+        "; current thread = " + Thread.currentThread().getName());
+
+    List<Flight> flights = Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 746", request.getFlightDate(), request.getFrom(), request.getTo())
+    );
+    System.out.println("Flight search successful");
+    return flights;
+  }
 }
--- a/resilience4j/springboot-resilience4j/src/main/resources/application.yml
+++ b/resilience4j/springboot-resilience4j/src/main/resources/application.yml
@@ -99,6 +99,25 @@ resilience4j:
        limitRefreshPeriod: 1s
        timeoutDuration: 500ms

+  timelimiter:
+    instances:
+
+      # TimeLimiter object used in TimeLimitingService.basicExample()
+      basicExample:
+        timeoutDuration: 2s
+
+      # TimeLimiter object used in TimeLimitingService.timeoutExample()
+      timeoutExample:
+        timeoutDuration: 500ms
+
+      # TimeLimiter object used in TimeLimitingService.eventsExample()
+      eventsExample:
+        timeoutDuration: 2s
+
+      # TimeLimiter object used in TimeLimitingService.fallbackExample()
+      fallbackExample:
+        timeoutDuration: 500ms
+
 management:
  endpoints:
    web: