From 5aab7f96a165d2c410ab35bba40a48f429333e1e Mon Sep 17 00:00:00 2001
From: Uma Vani Ravuri <umravuri@nisum.com>
Date: Thu, 23 Sep 2021 06:04:57 +0000
Subject: [PATCH] Replace TestEmployee.java
---
.../src/com/java8/practies/TestEmployee.java | 145 +++++++++++-------
1 file changed, 86 insertions(+), 59 deletions(-)
diff --git a/Java8PractiesProgram/src/com/java8/practies/TestEmployee.java b/Java8PractiesProgram/src/com/java8/practies/TestEmployee.java
index a0c9355..c381fa5 100644
--- a/Java8PractiesProgram/src/com/java8/practies/TestEmployee.java
+++ b/Java8PractiesProgram/src/com/java8/practies/TestEmployee.java
@@ -1,86 +1,113 @@
package com.java8.practies;
import java.util.ArrayList;
-
+import java.util.Comparator;
import java.util.List;
import java.util.Map;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Collector;
import java.util.stream.Collectors;
-
+import java.util.stream.Stream;
public class TestEmployee {
public static void main(String[] args) {
-
- ArrayList<Employee> list = new ArrayList<Employee>();
- list.add(new Employee("1", "Uma", "Vani", "IT"));
- list.add(new Employee("2", "Sujit", "Krishnan", "CSE"));
- list.add(new Employee("3", "Brayan", "Bra", "IT"));
- list.add(new Employee("4", "Allice", "Ali", "CSE"));
-
- list.add(new Employee("5", "Sco te", "Scote", "IT"));
- list.add(new Employee("6", "Rajesh", "Krishnan", "ECE"));
- list.add(new Employee("7", "Ramana", "Raju", "IT"));
- list.add(new Employee("8", "Raju", "Krishnan", "EEE"));
-
- list.add(new Employee("9", "Rishi", "Vani", "IT"));
- list.add(new Employee("10", "Dattu", "Krishnan", "EEE"));
-
- //1)list of employees, get the first employee from the list and return his fullName
- list.stream().limit(1)
- .forEach(x -> System.out.println("First employee Full Name is::" + x.firstName + x.lastName));
-
- //given a list of employees. Can you create a map with the count of employees each department has ?
- //with key as department name and count of employees as value.
- Map<String, Long> mapDepartment = list.stream()
- .collect(Collectors.groupingBy(Employee::getDepartmentNames, Collectors.counting()));
- mapDepartment.forEach((k, v) -> System.out.println((k + ":" + v)));
-
- //Given a map with the department name as key and value as list of employees belonging to that department.
- //when a search string is given, need to list out the employees whose firstname or lastname is matching(match should be case insensitive)
- Map<String, List<Employee>> mapEmployee = list.stream()
- .collect(Collectors.groupingBy(Employee::getDepartmentNames, Collectors.toList()));
- mapEmployee.forEach((k, v) -> System.out.println((k + ":" + v)));
-
- //Consider a list of employees, and if a department name is given as argument, list out the employees which doesn't belong to that department.
-
- List<Employee> filterEmp = list.stream().filter(x -> !x.getDepartmentNames().equals("IT"))
- .collect(Collectors.toList());
- filterEmp.forEach(x -> System.out.println(" Employee list whose Department is not IT" + x));
+ List<String> depList = new ArrayList<String>();
+ depList.add("IT");
+ depList.add("CSE");
+ depList.add("ECE");
+
+ List<String> depList2 = new ArrayList<String>();
+ depList2.add("ECE");
+ depList2.add("EEE");
+ depList2.add("IT");
+
+ List<Employee> listEmp = new ArrayList<Employee>();
+ listEmp.add(new Employee("1", "Uma", "vani", depList));
+ listEmp.add(new Employee("2", "Sujit", "Krishnan", depList2));
+ listEmp.add(new Employee("3", "Brayan", "Braya", depList));
+ listEmp.add(new Employee("4", "Allice", "Ali", depList2));
+ listEmp.add(new Employee("5", "Sco te","", depList2));
+ listEmp.add(new Employee("6", "Rajesh", "Krishnan", depList));
+ listEmp.add(new Employee("7", "Ramana", "Raju", depList2));
+ listEmp.add(new Employee("8", "Raju", "Krishnan", depList));
+ listEmp.add(new Employee("9", "Rishi", "Vani", depList));
+ listEmp.add(new Employee("10", "Dattu", "", depList2));
+
+
+ //list of employees, get the first employee from the list and return his fullName.
- // 6)Consider a list of employees, sort the employees by their firstName and
- // return the sorted list of employees.
- List<Employee> sortedEmployee = list.stream().sorted(new EmployeeComparator()).collect(Collectors.toList());
- sortedEmployee.forEach(x -> System.out.println("Sorted Employee based on firstName" + x));
+ listEmp.stream().map(emp -> {
+ Optional.ofNullable(emp)
+ .ifPresent(x -> System.out.println("First Employee Details :" + x.getFirstName() + x.getLastName()));
+ return emp;
+ }).findFirst();
+
+
+ //Consider a list of employees, sort the employees by their firstName and
+ listEmp.stream().sorted(Comparator.comparing(Employee::getFirstName)).collect(Collectors.toList()).forEach(System.out::println);
+
//Consider a list of employees, return the employee whose empId is highest
- Employee e = list.stream().max((e1, e2) -> e1.getId().compareTo(e2.getId())).get();
- System.out.println("Maximum Id Employee details" + e);
-
+ Optional<Employee> e = listEmp.stream().collect(Collectors.maxBy(Comparator.comparing(Employee::getId)));
+ if (e.isPresent()) {
+ System.out.print("Higest Employee Id"+e.get());
+ }
+
//Consider a list of employees, concat the fullName of all the employees with pipe (|) and return the concatenated string.
- String joinedString = list.stream().map(x -> x.firstName + x.lastName).collect(Collectors.joining("|"));
- System.out.println("Maximum Id Employee details-----------" + joinedString);
+
+ String joinedString = listEmp.stream().map(x -> x.firstName + x.lastName).collect(Collectors.joining("|"));
+ System.out.println("FullNames Of all employees concat with | symbol is :-----------" + joinedString);
+
//Consider a list of 10 employees, get the 8th employee and print his full name and department name.
- list.stream().sorted((e1, e2) -> e1.getId().compareTo(e2.getId())).skip(8).limit(1)
- .forEach(System.out::println);
+ listEmp.stream().sorted(Comparator.comparing(Employee::getId)).skip(8).limit(1).forEach(System.out::println);
//consider list of employees and list of employee ids. return the list of employees matching with the given list of employee ids.
- List<Employee> checkForMatches = new ArrayList<>();
- checkForMatches.add(new Employee("2", "siri", "raja", "CSE"));
- checkForMatches.add(new Employee("7", "roja", "rani", "CSE"));
- checkForMatches.add(new Employee("11", "roja", "rani", "CSE"));
-
+ List<Employee> checkForMatches = new ArrayList<>();
+ checkForMatches.add(new Employee("2", "siri", "raja", depList));
+ checkForMatches.add(new Employee("7", "roja", "rani", depList2));
+ checkForMatches.add(new Employee("11", "roja", "rani", depList));
+
- List<Employee> filteredList = list.stream()
- .filter(employee -> checkForMatches.stream().anyMatch(dept -> employee.getId().equals(dept.getId())))
- .collect(Collectors.toList());
+ listEmp.stream().filter(employee -> checkForMatches.stream().anyMatch(dept -> employee.getId().equals(dept.getId())))
+ .collect(Collectors.toList()).forEach(System.out::println);
- filteredList.forEach(x -> System.out.println("Employee matches" + x));
//Store ids are of 4 digit strings.if length of given storeId is less than 4 digits,you need to prefix with zeros and return a 4 digit storeId.
- list.stream().forEach(x->System.out.println("4 Digits employee Id::"+String.format("%04d", Integer.parseInt(x.id))));
+
+ listEmp.stream()
+ .map(employee -> {
+ Optional.ofNullable(employee)
+ .map(Employee::getId)
+ .map(id -> String.format("%04d", Integer.parseInt(id)))
+ .ifPresent(a -> employee.setId(a));
+ return employee.getId();
+ }).collect(Collectors.toList()).forEach(System.out::println);
+
+
+ //Consider a list of employees, and if a department name is given as argument, list out the employees which doesn't belong to that department.
+ listEmp.stream().filter(x -> !x.getDepartmentNames().stream().equals("EEE"))
+ .collect(Collectors.toList()).forEach(System.out::println);
+
+ listEmp.stream()
+ .flatMap(e -> e.getDepartmentNames().stream())
+ .filter(d -> !"EEE".equals(d.getDepartmentNames()))
+ .collect(Collectors.toList()).forEach(System.out::println);
+
+
+ //given a list of employees. Can you create a map with the count of employees each department has ?
+ //with key as department name and count of employees as value.
+ Stream<String> distinctDept=listEmp.stream()
+ .map(Employee::getDepartmentNames)
+ .flatMap(x->x.stream());
+ Map<String, Long> mapDepartment = distinctDept.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
+ mapDepartment.forEach((k, v) -> System.out.println((k + ":" + v)));
+
+
}
}
--
2.18.1