Merge branch 'BAEL-572' of https://github.com/tomekl007/tutorials into tomekl007-BAEL-572

rxjava/pom.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>rxjava</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.reactivex</groupId>
+            <artifactId>rxjava</artifactId>
+            <version>${rx.java.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <rx.java.version>1.2.5</rx.java.version>
+    </properties>
+
+</project>

rxjava/src/main/java/com/baelding/rxjava/ColdObservableBackpressure.java

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+package com.baelding.rxjava;
+
+
+import rx.Observable;
+import rx.Subscriber;
+import rx.schedulers.Schedulers;
+
+public class ColdObservableBackPressure {
+    public static void main(String[] args) throws InterruptedException {
+        Observable.range(1, 1_000_000)
+                .observeOn(Schedulers.computation())
+                .subscribe(v -> ComputeFunction.compute(v), Throwable::printStackTrace);
+
+        Thread.sleep(10_000);
+
+
+//        Observable.range(1, 1_000_000) //implementation of reactive pull backpressure on cold observable
+//                .subscribe(new Subscriber<Integer>() {
+//                    @Override
+//                    public void onStart() {
+//                        request(1);
+//                    }
+//
+//                    public void onNext(Integer v) {
+//                        compute(v);
+//
+//                        request(1);
+//                    }
+//
+//                    @Override
+//                    public void onError(Throwable ex) {
+//                        ex.printStackTrace();
+//                    }
+//
+//                    @Override
+//                    public void onCompleted() {
+//                        System.out.println("Done!");
+//                    }
+//                });
+
+    }
+
+
+}

rxjava/src/main/java/com/baelding/rxjava/ComputeFunction.java

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+package com.baelding.rxjava;
+
+
+import rx.Observable;
+
+import java.util.List;
+
+public class ComputeFunction {
+    public static void compute(Integer v) {
+        try {
+            System.out.println("compute integer v: " + v);
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void compute(List<Integer> v) {
+        try {
+            System.out.println("compute integer v: " + v);
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void compute(Observable<Integer> v) {
+        try {
+            v.forEach(System.out::println);
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+    public static void compute(Long v) {
+        try {
+            System.out.println("compute integer v: " + v);
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}

rxjava/src/main/java/com/baelding/rxjava/HotObservableBackPressureBatching.java

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+package com.baelding.rxjava;
+
+import rx.schedulers.Schedulers;
+import rx.subjects.PublishSubject;
+
+public class HotObservableBackPressureBatching {
+    public static void main(String[] args) throws InterruptedException {
+        PublishSubject<Integer> source = PublishSubject.<Integer>create();
+
+        source.window(500)
+                .observeOn(Schedulers.computation())
+                .subscribe(ComputeFunction::compute, Throwable::printStackTrace);
+
+
+        for (int i = 0; i < 1_000_000; i++) {
+            source.onNext(i);
+        }
+        Thread.sleep(10_000);
+    }
+
+}

rxjava/src/main/java/com/baelding/rxjava/HotObservableBackPressureBuffering.java

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+package com.baelding.rxjava;
+
+import rx.schedulers.Schedulers;
+import rx.subjects.PublishSubject;
+
+
+public class HotObservableBackPressureBuffering {
+    public static void main(String[] args) throws InterruptedException {
+        PublishSubject<Integer> source = PublishSubject.<Integer>create();
+
+        source
+                .buffer(1024)
+                .observeOn(Schedulers.computation())
+                .subscribe(ComputeFunction::compute, Throwable::printStackTrace);
+
+
+        for (int i = 0; i < 1_000_000; i++) {
+            source.onNext(i);
+        }
+        Thread.sleep(10_000);
+    }
+}

rxjava/src/main/java/com/baelding/rxjava/HotObservableBackPressureSkipping.java

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+package com.baelding.rxjava;
+
+import rx.schedulers.Schedulers;
+import rx.subjects.PublishSubject;
+
+import java.util.concurrent.TimeUnit;
+
+public class HotObservableBackPressureSkipping {
+    public static void main(String[] args) throws InterruptedException {
+        PublishSubject<Integer> source = PublishSubject.<Integer>create();
+
+        source.sample(100, TimeUnit.MILLISECONDS)
+//                .throttleFirst(100, TimeUnit.MILLISECONDS)
+                .observeOn(Schedulers.computation())
+                .subscribe(ComputeFunction::compute, Throwable::printStackTrace);
+
+
+        for (int i = 0; i < 1_000_000; i++) {
+            source.onNext(i);
+        }
+        Thread.sleep(10_000);
+    }
+}

rxjava/src/main/java/com/baelding/rxjava/HotObservableOnBackPressure.java

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+package com.baelding.rxjava;
+
+
+import rx.BackpressureOverflow;
+import rx.Observable;
+import rx.schedulers.Schedulers;
+
+public class HotObservableOnBackPressure {
+    public static void main(String[] args) throws InterruptedException {
+        Observable.range(1, 1_000_000)
+                .onBackpressureBuffer(16, () -> {
+                        },
+                        BackpressureOverflow.ON_OVERFLOW_DROP_OLDEST)
+                .observeOn(Schedulers.computation())
+                .subscribe(e -> {
+                }, Throwable::printStackTrace);
+
+
+        Observable.range(1, 1_000_000)
+                .onBackpressureDrop()
+                .observeOn(Schedulers.io())
+                .doOnNext(ComputeFunction::compute)
+                .subscribe(v -> {
+                }, Throwable::printStackTrace);
+        Thread.sleep(10_000);
+
+    }
+}

rxjava/src/main/java/com/baelding/rxjava/HotObservableWithoutBackPressure.java

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+package com.baelding.rxjava;
+
+
+import rx.schedulers.Schedulers;
+import rx.subjects.PublishSubject;
+
+public class HotObservableWithoutBackPressure {
+    public static void main(String[] args) throws InterruptedException {
+        PublishSubject<Integer> source = PublishSubject.<Integer>create();
+
+        source.observeOn(Schedulers.computation())
+                .subscribe(ComputeFunction::compute, Throwable::printStackTrace);
+
+
+        for (int i = 0; i < 1_000_000; i++) {
+            source.onNext(i);
+        }
+        Thread.sleep(10_000);
+    }
+}