TemporaryValue.java

package io.github.sasuked.legionguilds.utils.cache;

import java.util.concurrent.TimeUnit;
import java.util.function.Supplier;

public class TemporaryValue<T> {
  
  private final Supplier<T> supplier;
  
  private T currentValue;
  
  private final long timeToExpire;
  private final TimeUnit unit;
  
  long expirationTime;
  
  public TemporaryValue(Supplier<T> supplier, long timeToExpire, TimeUnit unit) {
    this.supplier = supplier;
    this.timeToExpire = timeToExpire;
    this.unit = unit;
    this.expirationTime = System.currentTimeMillis() + (unit.toSeconds(timeToExpire) * 1000);
  }
  
  public T getCurrentValue() {
    if (currentValue == null || isExpired()) {
      currentValue = supplier.get();
      expirationTime = System.currentTimeMillis() + (unit.toSeconds(timeToExpire) * 1000);
    }
    
    return currentValue;
  }
  
  public boolean isExpired() {
    return System.currentTimeMillis() >= expirationTime;
  }
}