U ovom ćemo primjeru naučiti pristupiti privatnim metodama i poljima klase u Javi.
Da biste razumjeli ovaj primjer, trebali biste imati znanje o sljedećim temama programiranja Java:
- Java metode
- Java Modifikatori pristupa
Primjer 1: Pristupite privatnim poljima pomoću metoda dobivanja i postavljanja
class Test ( // private variables private int age; private String name; // initialize age public void setAge(int age) ( this.age = age; ) // initialize name public void setName(String name) ( this.name = name; ) // access age public int getAge() ( return this.age; ) // access name public String getName() ( return this.name; ) ) class Main ( public static void main(String() args) ( // create an object of Test Test test = new Test(); // set value of private variables test.setAge(24); test.setName("Programiz"); // get value of private variables System.out.println("Age: " + test.getAge()); System.out.println("Name: " + test.getName()); ) )
Izlaz
Dob: 24 Ime: Programiz
U gornjem primjeru imamo privatne varijable s imenom age and name. Ovdje pokušavamo pristupiti privatnim varijablama iz druge klase koja se zove Main.
Za pristup privatnim varijablama koristili smo metodu getter i setter. Ovdje,
- setter metode
setAge()isetName()inicijalizira privatne varijable - getter metode
getAge()igetName()vraća vrijednost privatnih varijabli
Primjer 2: Pristupite privatnom polju i metodi pomoću Reflection
import java.lang.reflect.*; class Test ( // private variables private String name; // private method private void display() ( System.out.println("The name is " + name); ) ) class Main ( public static void main(String() args) ( try ( // create an object of Test Test test = new Test(); // create an object of the class named Class Class obj = test.getClass(); // access the private variable Field field = obj.getDeclaredField("name"); // make private field accessible field.setAccessible(true); // set value of field field.set(test, "Programiz"); // get value of field // and convert it in string String value = (String)field.get(test); System.out.println("Name: " + value); // access the private method Method() methods = obj.getDeclaredMethods(); System.out.println("Method Name: " + methods(0).getName()); int modifier = methods(0).getModifiers(); System.out.println("Access Modifier: " + Modifier.toString(modifier)); ) catch(Exception e) ( e.printStackTrace(); ) ) )
Izlaz
Naziv: Programiz Naziv metode: prikaz Modifikator pristupa: privatno
U ovom primjeru imamo privatno polje s imenom i privatnu metodu s imenom display(). Ovdje koristimo refleksiju za pristup privatnim poljima i metodama klase Test.
Da biste saznali više o razmišljanju, posjetite Java Reflection.
