Task 19 completed (Savchenkov)

src/main/java/com/epam/jf/common/classwork/lesson12/AnonymousClassExample.java

@@ -0,0 +1,31 @@
+package com.epam.jf.common.classwork.lesson12;
+
+import java.util.Date;
+
+public class AnonymousClassExample {
+
+    public static void main(String[] args) {
+        Date date = new Date() {
+
+            public int fieldA = 400;
+
+            @Override
+            public String toString() {
+                getDate1();
+                return "new version toString method";
+            }
+
+            private Date getDate1() {
+                return null;
+            }
+        }.getDate1();
+        System.out.println(date.getClass());
+
+        new Thread() {
+            @Override
+            public void run() {
+                super.run();
+            }
+        }.start();
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson12/BaseStream.java

@@ -0,0 +1,8 @@
+package com.epam.jf.common.classwork.lesson12;
+
+public interface BaseStream<T, S extends BaseStream<T, S>> {
+
+    S parallel();
+    S sequential();
+    S unordered();
+}

src/main/java/com/epam/jf/common/classwork/lesson12/HeapPollutionVarargs.java

@@ -0,0 +1,30 @@
+package com.epam.jf.common.classwork.lesson12;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class HeapPollutionVarargs {
+
+    public static void main(String[] args) {
+//        List<Integer>[] arrLists = new List<Integer>[100];
+//        Object[] objects = arrLists;
+//        List<String>[] arrStrings = (List<String>[])objects;
+//        arrStrings[0].add("123");
+        List<Integer> list = new ArrayList<>();
+        list.add(0);
+        List<Integer> list2 = new ArrayList<>();
+
+        List<String> strings = convert(list, list2);
+
+        String val = strings.get(0);
+        System.out.println(val);
+    }
+
+    private static List<String> convert(List<Integer>...args) {
+        Object[ ] objects = args;
+        return (List<String>) objects[0];
+    }
+
+
+}

src/main/java/com/epam/jf/common/classwork/lesson12/InnerExample.java

@@ -0,0 +1,70 @@
+package com.epam.jf.common.classwork.lesson12;
+
+public class InnerExample {
+
+    private int field = 200;
+
+    class A {
+
+//        private int field = 400;
+
+        public int getField() {
+            return InnerExample.this.field;
+        }
+    }
+
+    class B extends A {
+
+        private String val = "123";
+
+        class C extends B implements MyInterface {
+
+        }
+    }
+
+    public void setField(int field) {
+        this.field = field;
+    }
+}
+
+interface MyInterface {
+
+}
+
+class D extends InnerExample.A {
+
+    private int fieldD = 42;
+
+    public D(InnerExample obj) {
+        obj.super();
+    }
+
+    public static void main(String[] args) {
+        InnerExample ref = new InnerExample();
+        ref.setField(300);
+        D d = new D(ref);
+        System.out.println(d.getField());
+
+        ref.setField(400);
+        System.out.println(d.getField());
+
+        InnerExample innerExample = new InnerExample();
+        InnerExample.B b = innerExample.new B();
+    }
+
+    private void test() {
+        System.out.println(this.fieldD);
+
+        class E {
+            private int fieldE = 100;
+            public int getFieldD() {
+                return fieldD;
+            }
+        }
+
+        E e = null;
+        e.fieldE = 500;
+        System.out.println(e.getFieldD());
+    }
+}
+

src/main/java/com/epam/jf/common/classwork/lesson12/NestedExample.java

@@ -0,0 +1,17 @@
+package com.epam.jf.common.classwork.lesson12;
+
+public class NestedExample {
+
+    private int field = 100;
+
+    static class J extends K {
+
+        public J(NestedExample ref) {
+            ref.super();
+        }
+    }
+
+    class K {
+
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson12/Stream.java

@@ -0,0 +1,16 @@
+package com.epam.jf.common.classwork.lesson12;
+
+public interface Stream<T> extends BaseStream<T, Stream<T>> {
+
+    Stream<T> sorted();
+    Stream<T> ordered();
+}
+
+
+class StreamLauncher {
+
+    public static void main(String[] args) {
+        Stream<Integer> stream = null;
+        stream.sorted().ordered().parallel().sorted().ordered().unordered();
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson12/StringBuilderExample.java

@@ -0,0 +1,11 @@
+package com.epam.jf.common.classwork.lesson12;
+
+public class StringBuilderExample {
+
+    public static void main(String[] args) {
+        StringBuilder builder = new StringBuilder();
+        builder.append("123")
+               .append("123")
+               .insert(0, "12");
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson12/WTFGenerics.java

@@ -0,0 +1,33 @@
+package com.epam.jf.common.classwork.lesson12;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class WTFGenerics {
+
+    public static void main(String[] args) {
+        List<Integer> integers = Arrays.asList(1, 2, 3);
+//        getFirstNumber(integers);
+        Number first = getFirst(integers);
+        Integer firstGeneric = getFirstGeneric(integers);
+
+        String str = createList();
+    }
+
+    private static <T extends List> T createList() {
+        return (T)new ArrayList<>();
+    }
+
+    private static Number getFirstNumber(List<Number> list) {
+        return list.get(0);
+    }
+
+    private static Number getFirst(List<? extends Number> list) {
+        return list.get(0);
+    }
+
+    private static <T extends Number> T getFirstGeneric(List<T> list) {
+        return list.get(0);
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson13/AnnotationExample.java

@@ -0,0 +1,45 @@
+package com.epam.jf.common.classwork.lesson13;
+
+import java.lang.annotation.Annotation;
+import java.util.Arrays;
+
+/**
+ * abc
+ * @see SingleFieldAnnotation
+ */
+@MyAnnotation(author = "me", version = "1.0", values = {1, 2, 3})
+@SingleFieldAnnotation
+public class AnnotationExample {
+
+    @SingleFieldAnnotation
+    private final int value = 10;
+
+    @MyAnnotation(author = "me", version = "1.0")
+    @SingleFieldAnnotation("123")
+    public static void main(String[] args) {
+
+    }
+
+    @SuppressWarnings({"unused", "abc"})
+    private @SingleFieldAnnotation int method() {
+        return 0;
+    }
+
+    @Override
+    @SingleFieldAnnotation
+    public String toString() {
+        return super.toString();
+    }
+}
+
+class B extends AnnotationExample {
+
+    public static void main(String[] args) {
+        for (Annotation annotation : AnnotationExample.class.getAnnotations()) {
+            System.out.println(annotation);
+        }
+
+        MyAnnotation annotation = AnnotationExample.class.getAnnotation(MyAnnotation.class);
+        System.out.println(Arrays.toString(annotation.values()));
+    }
+}

src/main/java/com/epam/jf/common/classwork/lesson13/AnonymousClassExample.java

@@ -0,0 +1,40 @@
+package com.epam.jf.common.classwork.lesson13;
+
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+@SuppressWarnings("Convert2Lambda")
+public class AnonymousClassExample {
+
+    public static void main(String[] args) {
+        Integer[] arr = {1, 2, 3, 4, 1, 2, 3};
+
+        Arrays.sort(arr, new Comparator<Integer>() {
+            @Override
+            public int compare(Integer o1, Integer o2) {
+                return Integer.compare(o2, o1);
+            }
+        });
+
+        System.out.println(Arrays.toString(arr));
+
+        A a = new A() {
+            @Override
+            int method() {
+                return 1;
+            }
+        };
+        System.out.println(a.method());
+
+    }
+}
+
+class A {
+    int method() {
+        return 0;
+    }
+}
+
+
+

src/main/java/com/epam/jf/common/classwork/lesson13/DefaultMethodsExample.java

@@ -0,0 +1,31 @@
+package com.epam.jf.common.classwork.lesson13;
+
+interface Left {
+
+    default int getValue() {
+        return 10;
+    }
+}
+
+interface Right {
+
+    default int getValue() {
+        return -10;
+    }
+}
+
+class C {
+
+}
+
+public class DefaultMethodsExample extends C implements Left, Right {
+
+    @Override
+    public int getValue() {
+        return Left.super.getValue() + Right.super.getValue();
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new DefaultMethodsExample().getValue());
+    }
+}