Guava - Primitive Utilities

As primitive types of Java cannot be used to pass in generics or in collections as input, Guava provided a lot of Wrapper Utilities classes to handle primitive types as Objects. Following is the list of useful primitive processing utilities −

Useful Primitive Utilities

Example - Converting Byte Array to List and vice versa

GuavaTester.java

package com.tutorialspoint;

import java.util.List;

import com.google.common.primitives.Bytes;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBytes();
   }

   private void testBytes() {
      byte[] byteArray = {1,2,3,4,5,5,7,9,9};

      //convert array of primitives to array of objects
      List<Byte> objectArray = Bytes.asList(byteArray);
      System.out.println(objectArray.toString());

      //convert array of objects to array of primitives
      byteArray = Bytes.toArray(objectArray);
      System.out.print("[ ");
      
      for(int i = 0; i< byteArray.length ; i++) {
         System.out.print(byteArray[i] + " ");
      }

      System.out.println("]");
   }
}

Output

Run the GuavaTester and verify the output −

[1, 2, 3, 4, 5, 5, 7, 9, 9]
[ 1 2 3 4 5 5 7 9 9 ]

Example - Check if Element is present in Short Array

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Shorts;

public class GuavaTester {

   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testShorts();
   }

   private void testShorts() {
      short[] shortArray = {1,2,3,4,5,6,7,8,9};

      short data = 5;
      
      // check if element is present in the list of primitives or not
      System.out.println("5 is in list? " + Shorts.contains(shortArray, data));
      data = 6;
      System.out.println("6 is in list? " + Shorts.contains(shortArray, data));
   }
}

Output

Run the GuavaTester and verify the output −

5 is in list? true
6 is in list? false

Example - Getting Minimum/Maximum of Int Array

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Ints;

public class GuavaTester {

   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testInts();
   }

   private void testInts() {
      int[] intArray = {1,2,3,4,5,6,7,8,9};
      //Returns the minimum		
      System.out.println("Min: " + Ints.min(intArray));

      //Returns the maximum		
      System.out.println("Max: " + Ints.max(intArray));

      //get the byte array from an integer
      byte[] byteArray = Ints.toByteArray(20000);
      
      for(int i = 0; i< byteArray.length ; i++) {
         System.out.print(byteArray[i] + " ");
      }
   }
}

Verify the Result

Run the GuavaTester and verify the output −

Min: 1
Max: 9
0 0 78 32