Immutatbility class example in java

Ahmad Mujtaba answered on August 7, 2022 Popularity 3/10 Helpfulness 1/10

answer Immutatbility class example in java

Immutatbility class example in java

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ImmutableClass.java
import java.util.Date;
 
/**
* Always remember that your instance variables will be either mutable or immutable.
* Identify them and return new objects with copied content for all mutable objects.
* Immutable variables can be returned safely without extra effort.
* */
public final class ImmutableClass
{
 
  /**
  * Integer class is immutable as it does not provide any setter to change its content
  * */
  private final Integer immutableField1;
 
  /**
  * String class is immutable as it also does not provide setter to change its content
  * */
  private final String immutableField2;
 
  /**
  * Date class is mutable as it provide setters to change various date/time parts
  * */
  private final Date mutableField;
 
  //Default private constructor will ensure no unplanned construction of class
  private ImmutableClass(Integer fld1, String fld2, Date date)
  {
    this.immutableField1 = fld1;
    this.immutableField2 = fld2;
    this.mutableField = new Date(date.getTime());
  }
 
  //Factory method to store object creation logic in single place
  public static ImmutableClass createNewInstance(Integer fld1, String fld2, Date date)
  {
    return new ImmutableClass(fld1, fld2, date);
  }
 
  //Provide no setter methods
 
  /**
  * Integer class is immutable so we can return the instance variable as it is
  * */
  public Integer getImmutableField1() {
    return immutableField1;
  }
 
  /**
  * String class is also immutable so we can return the instance variable as it is
  * */
  public String getImmutableField2() {
    return immutableField2;
  }
 
  /**
  * Date class is mutable so we need a little care here.
  * We should not return the reference of original instance variable.
  * Instead a new Date object, with content copied to it, should be returned.
  * */
  public Date getMutableField() {
    return new Date(mutableField.getTime());
  }
 
  @Override
  public String toString() {
    return immutableField1 +" - "+ immutableField2 +" - "+ mutableField;
  }
}

Popularity 3/10 Helpfulness 1/10 Language java

Source: Grepper

Tags: class java

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Contributed on Aug 07 2022

Ahmad Mujtaba

0 Answers Avg Quality 2/10

Immutatbility class example in java

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