In this section, you will learn about the least-recently- used(LRU) cache in Java.
Implementing a Least-Recently-Used(LRU) Cache
In this section, you will learn about the least-recently- used(LRU) cache in Java. LRU Cache helps you how to use the buffer and how to limit or fixed the size of buffer and how to manage storing and retrieving process of the buffer which size is limited.
In this section, you can create a LRU(least-recently-used) Cache and manage it efficiently. Here the given program takes a in numeric input to fix the size of the LRU Cache. If your entry exceeds the size of the LRU Cache the the eldest element with key is removed. LRU Cache is implemented through the LinkedHashMap class. LinkedHashMap holds values with unique key. You you store values with a duplicate key then the LinkedHashMap replace the old value of that key with the new value of the key.
Code Description:
This program shows the object keys and values by using the LRU cache. Many methods and APIs which have been used in the following program are explained as follows:
LinkedHashMap:
This is the class of the java.util.*;
package. This class is also used for the implementing the doubly linked list
which tracks either insertion or access order. The put() method is used for the
insertion process to the LinkedHashMap with the value and the unique key
regarding the value.
put(Object key, Object value):
This method has been used to add a value with it's
unique key in the LRU Cache. This method of the LinkedHashMap class takes two
argument in which first is the key and another is the value for the specified
key.
Map.Entry:
This interface returns the view of map of collection . The
Map.Entry objects are valid only to the duration of the iteration. This
is the nested class of the Map class from the java.util.*; package.
e.getKey():
Above method of the Map.Entry class which
returns the key corresponding to the value. Here 'e' is the instance of the Map.Entry
class.
e.getValue():
Above written is also a method of the Map.Entry
class which returns the value corresponding to the key of the index of the LRU
Cache.
Here is the code of program:
import java.util.*;
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