emps.strumieniowo - pierwsze kroki

PC22-ZaawansowaneElementyJavy/src/main/java/emps/strumieniowo/Employee.java

+package emps.strumieniowo;
+
+import java.time.LocalDate;
+import java.util.Objects;
+
+// To jest przykład "normalnej klasy" przygotowanej po to, aby tworzyć obiekty tej klasy.
+// Na takie klasy mówi się "klasa modelu".
+public class Employee {
+	private int employeeId;
+	private String firstName;
+	private String lastName;
+	private String jobTitle;
+	private int salary;
+	private LocalDate hireDate;
+	private String departmentName;
+	private String streetAddress;
+	private String postalCode;
+	private String city;
+	private String country;
+	
+	public Employee(int employeeId, String firstName, String lastName, String jobTitle, int salary, LocalDate hireDate,
+			String departmentName, String streetAddress, String postalCode, String city, String country) {
+		this.employeeId = employeeId;
+		this.firstName = firstName;
+		this.lastName = lastName;
+		this.jobTitle = jobTitle;
+		this.salary = salary;
+		this.hireDate = hireDate;
+		this.departmentName = departmentName;
+		this.streetAddress = streetAddress;
+		this.postalCode = postalCode;
+		this.city = city;
+		this.country = country;
+	}
+
+	public int getEmployeeId() {
+		return employeeId;
+	}
+
+	public void setEmployeeId(int employeeId) {
+		this.employeeId = employeeId;
+	}
+
+	public String getFirstName() {
+		return firstName;
+	}
+
+	public void setFirstName(String firstName) {
+		this.firstName = firstName;
+	}
+
+	public String getLastName() {
+		return lastName;
+	}
+
+	public void setLastName(String lastName) {
+		this.lastName = lastName;
+	}
+
+	public String getJobTitle() {
+		return jobTitle;
+	}
+
+	public void setJobTitle(String jobTitle) {
+		this.jobTitle = jobTitle;
+	}
+
+	public int getSalary() {
+		return salary;
+	}
+
+	public void setSalary(int salary) {
+		this.salary = salary;
+	}
+
+	public LocalDate getHireDate() {
+		return hireDate;
+	}
+
+	public void setHireDate(LocalDate hireDate) {
+		this.hireDate = hireDate;
+	}
+
+	public String getDepartmentName() {
+		return departmentName;
+	}
+
+	public void setDepartmentName(String departmentName) {
+		this.departmentName = departmentName;
+	}
+
+	public String getStreetAddress() {
+		return streetAddress;
+	}
+
+	public void setStreetAddress(String streetAddress) {
+		this.streetAddress = streetAddress;
+	}
+
+	public String getPostalCode() {
+		return postalCode;
+	}
+
+	public void setPostalCode(String postalCode) {
+		this.postalCode = postalCode;
+	}
+
+	public String getCity() {
+		return city;
+	}
+
+	public void setCity(String city) {
+		this.city = city;
+	}
+
+	public String getCountry() {
+		return country;
+	}
+
+	public void setCountry(String country) {
+		this.country = country;
+	}
+
+	@Override
+	public String toString() {
+		return "Employee [employeeId=" + employeeId + ", firstName=" + firstName + ", lastName=" + lastName
+				+ ", jobTitle=" + jobTitle + ", salary=" + salary + ", hireDate=" + hireDate + ", departmentName="
+				+ departmentName + ", streetAddress=" + streetAddress + ", postalCode=" + postalCode + ", city=" + city
+				+ ", country=" + country + "]";
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(city, country, departmentName, employeeId, firstName, hireDate, jobTitle, lastName,
+				postalCode, salary, streetAddress);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Employee other = (Employee) obj;
+		return Objects.equals(city, other.city) && Objects.equals(country, other.country)
+				&& Objects.equals(departmentName, other.departmentName) && employeeId == other.employeeId
+				&& Objects.equals(firstName, other.firstName) && Objects.equals(hireDate, other.hireDate)
+				&& Objects.equals(jobTitle, other.jobTitle) && Objects.equals(lastName, other.lastName)
+				&& Objects.equals(postalCode, other.postalCode) && salary == other.salary
+				&& Objects.equals(streetAddress, other.streetAddress);
+	}
+	
+}

PC22-ZaawansowaneElementyJavy/src/main/java/emps/strumieniowo/ObslugaCSV.java

+package emps.strumieniowo;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.PrintWriter;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+
+public class ObslugaCSV {
+	private static final String NAGLOWEK = "employee_id;first_name;last_name;job_title;salary;hire_date;department_name;address;postal_code;city;country";
+	private static final String SEP = ";";
+	
+	private ObslugaCSV() {
+		// nie wolno tworzyć obiektu
+	}
+
+	public static List<Employee> wczytaj(File plik) {
+		List<Employee> emps = new ArrayList<>();
+		try(Scanner scanner = new Scanner(plik)) {
+			scanner.nextLine();
+			
+			while(scanner.hasNextLine()) {
+				String linia = scanner.nextLine();
+				String[] t = linia.split(SEP, 11);
+				Employee emp = new Employee(Integer.parseInt(t[0]), t[1], t[2], t[3],
+						Integer.parseInt(t[4]), LocalDate.parse(t[5]), t[6], t[7], t[8], t[9], t[10]);
+				
+				emps.add(emp);
+			}
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		}
+		
+		return emps;
+	}
+	
+	public static List<Employee> wczytaj(String sciezka) {
+		return wczytaj(new File(sciezka));
+	}
+	
+	public static void zapisz(List<Employee> lista, File plik) {
+		try(PrintWriter out = new PrintWriter(plik)) {
+			out.println(NAGLOWEK);
+			for (Employee emp : lista) {
+				out.print(emp.getEmployeeId());
+				out.print(SEP);
+				out.print(emp.getFirstName());
+				out.print(SEP);
+				out.print(emp.getLastName());
+				out.print(SEP);
+				out.print(emp.getJobTitle());
+				out.print(SEP);
+				out.print(emp.getSalary());
+				out.print(SEP);
+				out.print(emp.getHireDate());
+				out.print(SEP);
+				out.print(emp.getDepartmentName());
+				out.print(SEP);
+				out.print(emp.getStreetAddress());
+				out.print(SEP);
+				out.print(emp.getPostalCode());
+				out.print(SEP);
+				out.print(emp.getCity());
+				out.print(SEP);
+				out.print(emp.getCountry());
+				out.println();
+			}
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		}
+	}
+
+	public static void zapisz(List<Employee> lista, String sciezka) {
+		zapisz(lista, new File(sciezka));
+	}
+}

PC22-ZaawansowaneElementyJavy/src/main/java/emps/strumieniowo/P0_ForEach.java

+package emps.strumieniowo;
+
+import java.util.List;
+
+// W tej wersji operację forEach wywołujemy bezpośrednio na liście, bez jawnego użycia strumieni.
+public class P0_ForEach {
+
+	public static void main(String[] args) {
+		List<Employee> emps = ObslugaCSV.wczytaj("emps.csv");
+		
+		int zmienna = 0;
+		
+		// Zamiast pisać pętlę for(Employee emp : emps) { ROBOTA; }
+		// można wywołać operację forEach i "ROBOTĘ" przekazać w formie wyrażenia lambda:
+		
+		emps.forEach(emp -> {
+			System.out.print(" * ");
+			System.out.println(emp.getFirstName() + " " + emp.getLastName());
+			// w obrębie wyrażeń lambda nie wolno modyfikować zmiennych lokalnych zdef. przed lambdą
+			// zmienna++;
+		});
+		System.out.println("-----------------");
+		
+		// Gdy do wykonania jest tylko jedna czynność, można bez nawiasów klamrowych (i bez średnika):
+		emps.forEach(emp -> System.out.print(emp.getCity() + ", "));
+		System.out.println();
+		System.out.println("-----------------");
+		System.out.println();
+		
+		// Jeśli wykonujemy metodę dla całego obiektu, np. System.out.println(emp);
+		// to zamiast lambdy możemy użyć referencji do metody
+		
+		emps.forEach(System.out::println);
+	}
+
+}