add Composite Pattern

Author: dslsyeoh

src/com/dsl/design/pattern/composite/CompositePatternDemo.java

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+/*
+ * Author Steven Yeoh
+ * Copyright (c) 2019. All rights reserved.
+ */
+
+package com.dsl.design.pattern.composite;
+
+import java.util.stream.Stream;
+
+public class CompositePatternDemo
+{
+    public static void main(String[] args)
+    {
+        Developer developer = new Developer("Tom", 8000, "Team Leader");
+        Developer developer2 = new Developer("Sam", 6000, "Senior Developer");
+        Developer developer3 = new Developer("Bob", 4000, "Developer");
+        Developer developer4 = new Developer("King", 3000, "Junior Developer");
+        Developer developer5 = new Developer("Chris", 3000, "Junior Developer");
+
+        Salesman salesman = new Salesman("Paul", 5000, "Executive Salesman");
+        Salesman salesman2 = new Salesman("Crux", 3000, "Salesman");
+        Salesman salesman3 = new Salesman("Mark", 3000, "Salesman");
+
+        Manager manager = new Manager("Max", 6500, "Project Manager");
+        Manager manager2 = new Manager("Isabelle", 6000, "Marketing Manager");
+
+        Stream.of(developer, developer2, developer3, developer4, developer5).forEach(manager::addEmployee);
+        Stream.of(salesman, salesman2, salesman3).forEach(manager2::addEmployee);
+
+        manager.printDetails();
+
+        manager2.removeEmployee(salesman2);
+        manager2.printDetails();
+    }
+}

src/com/dsl/design/pattern/composite/Developer.java

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+/*
+ * Author Steven Yeoh
+ * Copyright (c) 2019. All rights reserved.
+ */
+
+package com.dsl.design.pattern.composite;
+
+public class Developer implements Employee
+{
+    private String name;
+    private double salary;
+    private String position;
+
+    public Developer(String name, double salary, String position)
+    {
+        this.name = name;
+        this.salary = salary;
+        this.position = position;
+    }
+
+    @Override
+    public void printDetails()
+    {
+        System.out.println(String.format("Name: %s Salary: %.2f Position: %s", name, salary, position));
+    }
+}

src/com/dsl/design/pattern/composite/Employee.java

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+/*
+ * Author Steven Yeoh
+ * Copyright (c) 2019. All rights reserved.
+ */
+
+package com.dsl.design.pattern.composite;
+
+public interface Employee
+{
+    void printDetails();
+}

src/com/dsl/design/pattern/composite/Manager.java

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+/*
+ * Author Steven Yeoh
+ * Copyright (c) 2019. All rights reserved.
+ */
+
+package com.dsl.design.pattern.composite;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Manager implements Employee
+{
+    private String name;
+    private double salary;
+    private String position;
+    private List<Employee> employees;
+
+    public Manager(String name, double salary, String position)
+    {
+        this.name = name;
+        this.salary = salary;
+        this.position = position;
+        this.employees = new ArrayList<>();
+    }
+
+    public void addEmployee(Employee employee)
+    {
+        employees.add(employee);
+    }
+
+    public void removeEmployee(Employee employee)
+    {
+        employees.remove(employee);
+    }
+
+    public String getName()
+    {
+        return name;
+    }
+
+    public double getSalary()
+    {
+        return salary;
+    }
+
+    public String getPosition()
+    {
+        return position;
+    }
+
+    public List<Employee> getEmployees()
+    {
+        return employees;
+    }
+
+    @Override
+    public void printDetails()
+    {
+        System.out.println("=============== Management ===============");
+        System.out.println(String.format("Name: %s Salary: %.2f Position: %s", name, salary, position));
+        System.out.println("=============== Management ===============");
+        employees.forEach(Employee::printDetails);
+        System.out.println();
+    }
+}

src/com/dsl/design/pattern/composite/Salesman.java

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+/*
+ * Author Steven Yeoh
+ * Copyright (c) 2019. All rights reserved.
+ */
+
+package com.dsl.design.pattern.composite;
+
+public class Salesman implements Employee
+{
+    private String name;
+    private double salary;
+    private String position;
+
+    public Salesman(String name, double salary, String position)
+    {
+        this.name = name;
+        this.salary = salary;
+        this.position = position;
+    }
+
+    @Override
+    public void printDetails()
+    {
+        System.out.println(String.format("Name: %s salary: %.2f position: %s", name, salary, position));
+    }
+}