java/se: add inner class sample

Author: Alice52

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/anonymous/AnonymousInterface.java

@@ -0,0 +1,19 @@
+package cn.edu.ntu.javase.syntax.iclass.anonymous;
+
+import java.util.function.Consumer;
+
+/**
+ * type3: anonymous inner class <br>
+ * 1. anonymous in known as implements interface as parameter. <br>
+ * 2. anonymous inner class have all access to outer class. <br>
+ * 3. outer class have a no access to anonymous inner class: <br>
+ * - anonymous inner class can define property，and can only used in local, <br>
+ * - and cannot used in outer class due to no class name.<br>
+ * 4. even cannot create or get anonymous instance.<br>
+ * 5. anonymous just define implements and it will not execute besides call interface method.
+ * <br>
+ * 6. create anonymous for each interface method call.<br>
+ */
+interface AnonymousInterface {
+    void accept(String tag, Consumer consumer);
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/anonymous/Test.java

@@ -0,0 +1,29 @@
+package cn.edu.ntu.javase.syntax.iclass.anonymous;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.function.Consumer;
+
+@Slf4j
+public class Test {
+
+    int a;
+
+    public void anonymousClassTest() {
+        // this just define implements and it will not execute besides call interface method.
+        AnonymousInterface anonymousInterface =
+                new AnonymousInterface() {
+                    // can define property in anonymous class，and can only used in local.
+                    int field = a;
+
+                    @Override
+                    public void accept(String tag, Consumer consumer) {
+                        consumer.accept(tag);
+                    }
+                };
+
+        // create anonymous for each interface method call.
+        anonymousInterface.accept("obj1", (Object a) -> log.info(a.toString()));
+        anonymousInterface.accept("obj3", a -> log.info(a.toString()));
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/callback/Callee.java

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+package cn.edu.ntu.javase.syntax.iclass.func.callback;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * @author Zack Zhang
+ */
+@Slf4j
+public class Callee extends MyIncrement {
+    private int i = 0;
+
+    private void incr() {
+        i++;
+        log.info("{}", i);
+    }
+
+    private class Closure implements Incrementable {
+        public void increment() {
+            incr();
+        }
+    }
+
+    public Incrementable getCallbackReference() {
+        return new Closure();
+    }
+
+    public static void main(String[] args) {
+        Callee callee = new Callee();
+        callee.increment();
+        Incrementable callbackReference = callee.getCallbackReference();
+        callbackReference.increment();
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/callback/Incrementable.java

@@ -0,0 +1,5 @@
+package cn.edu.ntu.javase.syntax.iclass.func.callback;
+
+public interface Incrementable {
+    void increment();
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/callback/MyIncrement.java

@@ -0,0 +1,11 @@
+package cn.edu.ntu.javase.syntax.iclass.func.callback;
+
+public class MyIncrement {
+    public void increment() {
+        System.out.println("Other increment()");
+    }
+
+    static void f(MyIncrement f) {
+        f.increment();
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/inherit/Example1.java

@@ -0,0 +1,8 @@
+package cn.edu.ntu.javase.syntax.iclass.func.inherit;
+
+public class Example1 {
+    public String name() {
+        return "longjiazuo";
+    }
+
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/inherit/Example2.java

@@ -0,0 +1,8 @@
+package cn.edu.ntu.javase.syntax.iclass.func.inherit;
+
+public class Example2 {
+    public String address() {
+        return "longjiazuo";
+    }
+
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/inherit/MoreInherit.java

@@ -0,0 +1,33 @@
+package cn.edu.ntu.javase.syntax.iclass.func.inherit;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Deprecated
+public class MoreInherit {
+    private class test1 extends Example1 {
+        public String name() {
+            return super.name();
+        }
+    }
+
+    private class test2 extends Example2 {
+        public String address() {
+            return super.address();
+        }
+    }
+
+    public String name() {
+        return new test1().name();
+    }
+
+    public String age() {
+        return new test2().address();
+    }
+
+    public static void main(String args[]) {
+        MoreInherit mi = new MoreInherit();
+        log.info("姓名:" + mi.name());
+        log.info("地址:" + mi.age());
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/inherit/MoreInheritV2.java

@@ -0,0 +1,24 @@
+package cn.edu.ntu.javase.syntax.iclass.func.inherit;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class MoreInheritV2 {
+
+    private Example1 e1 = new Example1();
+    private Example2 e2 = new Example2();
+
+    public String name() {
+        return e1.name();
+    }
+
+    public String age() {
+        return e2.address();
+    }
+
+    public static void main(String args[]) {
+        MoreInheritV2 mi = new MoreInheritV2();
+        log.info("姓名:" + mi.name());
+        log.info("地址:" + mi.age());
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/oop/Example.java

@@ -0,0 +1,14 @@
+package cn.edu.ntu.javase.syntax.iclass.func.oop;
+
+public class Example {
+    private class InsideClass implements Interface {
+        public void test() {
+            System.out.println("这是一个测试");
+        }
+    }
+
+    public Interface getIn() {
+        return new InsideClass();
+    }
+
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/oop/Interface.java

@@ -0,0 +1,5 @@
+package cn.edu.ntu.javase.syntax.iclass.func.oop;
+
+public interface Interface {
+    void test();
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/func/oop/TestFunc.java

@@ -0,0 +1,9 @@
+package cn.edu.ntu.javase.syntax.iclass.func.oop;
+
+public class TestFunc {
+    public static void main(String args[]) {
+        Example a = new Example();
+        Interface a1 = a.getIn();
+        a1.test();
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/innerc/OuterClass.java

@@ -0,0 +1,36 @@
+package cn.edu.ntu.javase.syntax.iclass.innerc;
+
+import lombok.Data;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Data
+public class OuterClass {
+
+    int a = 1;
+    private int op;
+    private static int sop;
+    private InnerClass innerClass = new InnerClass();
+
+
+    public class InnerClass {
+        // inner class cannot contains static properties.
+        // private static int p;
+        int a = 2;
+        private int ip;
+
+        public void accessOp() {
+            log.info("out class properties: {}-{}", op, sop);
+        }
+
+        public void method() {
+            int a = 3;
+            // 访问方法内部变量
+            log.info("{}", a);
+            // 访问内部类的成员变量
+            log.info("{}", this.a);
+            // 访问外部内的成员变量
+            log.info("{}", OuterClass.this.a);
+        }
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/innerc/Test.java

@@ -0,0 +1,10 @@
+package cn.edu.ntu.javase.syntax.iclass.innerc;
+
+public class Test {
+
+    public static void main(String[] args) {
+
+        OuterClass.InnerClass inner = new OuterClass().new InnerClass();
+        inner.accessOp();
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/localc/OuterClass.java

@@ -0,0 +1,20 @@
+package cn.edu.ntu.javase.syntax.iclass.localc;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class OuterClass {
+    public int op;
+
+    public void getXx() {
+        int mp = 1;
+
+        final class LocalInner {
+            public int ip;
+
+            public void getX() {
+                log.info("{}-{}-{}", op, mp, ip);
+            }
+        }
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/staticc/OuterClass.java

@@ -0,0 +1,36 @@
+package cn.edu.ntu.javase.syntax.iclass.staticc;
+
+import lombok.Data;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class OuterClass {
+    int a = 1;
+    private int op;
+    private static int sop;
+    private InnerClass innerClass = new InnerClass();
+
+    @Data
+    public static class InnerClass {
+        int a = 2;
+
+        static int sp;
+
+        private int ip;
+
+        public void accessOp() {
+            log.info("out class properties: {}", sop);
+        }
+
+        public void method() {
+
+            int a = 3;
+            // 访问方法内部变量
+            log.info("{}", a);
+            // 访问内部类的成员变量
+            log.info("{}", this.a);
+            // 访问外部内的成员变量: error
+            // log.info("{}", OuterClass.this.a);
+        }
+    }
+}

java/javase/javase-syntax/src/main/java/cn/edu/ntu/javase/syntax/iclass/staticc/Test.java

@@ -0,0 +1,13 @@
+package cn.edu.ntu.javase.syntax.iclass.staticc;
+
+
+import lombok.val;
+
+public class Test {
+    public static void main(String[] args) {
+        val a = OuterClass.InnerClass.sp;
+        OuterClass.InnerClass inner = new OuterClass.InnerClass();
+        inner.accessOp();
+        int ip = inner.getIp();
+    }
+}