package com.expgiga.Java8;

/**
 *
 */
public class Employee {
    private String name;
    private int age;
    private double salary;
    private int id;

    private Status status;

    public Employee() {
    }

    public Employee(String name, int age, double salary) {
        this.name = name;
        this
 
.age = age;
        this.salary = salary;
    }

    public Employee(String name, int age, double salary, Status status) {
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.status = status;
    }

    public String getName() {
        return name;
    }

    public void 
 
setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    @Override
 
public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", salary=" + salary +
                ", id=" + id +
                ", status=" + status +
                '}';
    }

    public Employee(int id) {
        this.id = id;
    }

    public Employee(int id, int age) {
        this.id = id;
        this.age = age;
    }

    @Override
public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Employee employee = (Employee) o;

        if (age != employee.age) return false;
        if (Double.compare(employee.salary, salary) != 0) return false;
        if (id != employee.id) return false;
        return name != null ? name.equals(employee.name) : employee.name == null;
    }

    @Override
public int hashCode() {
        int result;
        long temp;
        result = name != null ? name.hashCode() : 0;
        result = 31 * result + age;
        temp = Double.doubleToLongBits(salary);
        result = 31 * result + (int) (temp ^ (temp >>> 32));
        result = 31 * result + id;
        return result;
    }

    public Status getStatus() {
        return status;
    }

    public void setStatus(Status status) {
        this.status = status;
    }

    public enum Status {
        FREE,
        BUSY,
        VOCATION;
    }
}

package com.expgiga.Java8;

import java.util.*;
import java.util.stream.Collector;
import java.util.stream.Collectors;

/**
 * Java8 Stream的終止操作:
 */
public class TestStreamAPI {
    public static void main(String[] args) {
        /*
         * 查詢與匹配          * allMatch
          * anyMatch
          * noneMatch
          * findFirst
          * findAny
          * count
          * max
          * min
          *
         */
List<Employee> employeeList = Arrays.asList(
                new Employee("zhangsan", 18, 19999, Employee.Status.FREE),
                new Employee("lisi", 28, 29999, Employee.Status.BUSY),
                new Employee("wangwu", 38, 39999, Employee.Status.VOCATION),
                new Employee("zhaoliu", 16, 17999, Employee.Status.BUSY),
                new Employee("tianqi", 6, 12999, Employee.Status.FREE),
                new Employee("tianqi", 6, 12999, Employee.Status.FREE)
        );

        /*
         * 歸約         * reduce
         */
List<Integer> list = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
        Integer sum = list.stream()
                .reduce(0, (x, y) -> x + y);
        System.out.println(sum);

        System.out.println("-----------------------------------------------");

        Optional<Double> op = employeeList.stream() //可能為空 所有返回的是Optional
.map(Employee::getSalary)
                .reduce(Double::sum);
        System.out.println(op.get());

        /*
         * 收集         * collect
         */
List<String> list2 = employeeList.stream()
                .map(Employee::getName)
                .collect(Collectors.toList());
        list2.forEach(System.out::println);

        Set<String> set = employeeList.stream()
                .map(Employee::getName)
                .collect(Collectors.toSet());
        set.forEach(System.out::println);

        System.out.println("-----------------------------------------------");

        HashSet<String> hs = employeeList.stream()
                .map(Employee::getName)
                .collect(Collectors.toCollection(HashSet::new));
        hs.forEach(System.out::println);

        //總數
Long count = employeeList.stream()
                .collect(Collectors.counting());
        System.out.println(count);

        //平均值
Double avg = employeeList.stream()
                .collect(Collectors.averagingDouble(Employee::getSalary));
        System.out.println(avg);

        //總和
Double sumSalary = employeeList.stream()
                .collect(Collectors.summingDouble(Employee::getSalary));
        System.out.println(sumSalary);

        //最大值
Optional<Employee> max = employeeList.stream()
                .collect(Collectors.maxBy((e1, e2) -> Double.compare(e1.getSalary(), e2.getSalary())));
        System.out.println(max.get());

        //最小值
Optional<Double> min = employeeList.stream()
                .map(Employee::getSalary)
                .collect(Collectors.minBy(Double::compare));
        System.out.println(min.get());


        //分組
Map<Employee.Status, List<Employee>> map = employeeList.stream()
                .collect(Collectors.groupingBy(Employee::getStatus));
        System.out.println(map);

        //多級分組
Map<Employee.Status, Map<String, List<Employee>>> mapMap = employeeList.stream()
                .collect(Collectors.groupingBy(Employee::getStatus, Collectors.groupingBy((e) -> {
                    if (((Employee)e).getAge() <= 18) {
                        return "dud";
                    } else if(((Employee)e).getAge() <= 30) {
                        return "heh";
                    } else {
                        return "hah";
                    }
                })));
        System.out.println(mapMap);

        //分片(分割槽)
Map<Boolean, List<Employee>> booleanListMap = employeeList.stream()
                .collect(Collectors.partitioningBy((e) -> e.getSalary() > 13000));
        System.out.println(booleanListMap);

        //其他
DoubleSummaryStatistics dss = employeeList.stream()
                .collect(Collectors.summarizingDouble(Employee::getSalary));
        System.out.println(dss.getSum());

        String str = employeeList.stream()
                .map(Employee::getName)
                .collect(Collectors.joining());
        System.out.println(str);
    }
}