array. length

Arrays.sort(array_name);

Arrays.copyOfRange(array_name, 0, array_name.length);

import java.util.*;
public class Main {
   public static void main(String[] args) {

      // declare an integer type of array and store some random value to it by static input method
      int[] inputArray = { 122, 34, 25, 67 , 87};

      // call the user-defined method and pass the inputArray[]
      rankedArray(inputArray);

      // Print the array as output
      System.out.println("Array with replaced ranks = " + Arrays.toString(inputArray));
   }
   //user-defined method to replace the elements of given array by their ranks
   static void rankedArray(int[] inpArr) {
      // declare a temporary array and store the copied array of input array
      int temp[] = Arrays.copyOfRange(inpArr, 0, inpArr.length);
      // Sort the values of temp[] array in ascending order
      Arrays.sort(temp);
      //initiate the nested-loop to find the corresponding position of given array
      for(int i=0; i< inpArr.length; i++){
         for(int j=0; j< inpArr.length; j++){
            if(temp[j]==inpArr[i]){
               inpArr[i] = j+1;
               break;
            }
         }
      }
   }
}

Array with replaced ranks = [5, 2, 1, 3, 4]

import java.util.*;
public class Main {
   public static void main(String[] args) {

      // declare and initialize integer type array
      int[] inputArray = { 34,53,12,64,76};

      // call the user-defined method
      rankedArray(inputArray);

      // Print the array as output
      System.out.println("Array with replaced ranks = " +
      Arrays.toString(inputArray));
   }

   //user-defined method to replace the elements of given array by their ranks
   static void rankedArray(int[] inpArr) {

      // declare a temporary array and store the copied inputed array
      int temp[] = Arrays.copyOfRange(inpArr, 0, inpArr.length);

      // Sort the temp[] array in ascending order
      Arrays.sort(temp);

      // create object of HashMap class to store the maped rank of array's elements
      Map hashRanks = new HashMap<>();

      //declare an integer to store the value of corresponding Ranks of array's elements
      int correspondingRank = 1;

      //intiate the loop
      for (int i = 0; i < temp.length; i++) {

         //declare an integer to store the elements of array
         int num = temp[i];

         // Update the corresponding Ranks of array's elements
         if (hashRanks.get(num) == null) {
            hashRanks.put(num, correspondingRank);
            correspondingRank++;
         }
      }

      // Assign the corresponding Ranks to the array's elements
      for (int i = 0; i < inpArr.length; i++) {
         int num = inpArr[i];
         inpArr[i] = (int)hashRanks.get(inpArr[i]);
      }
   }
}

Note: Main.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Array with replaced ranks = [2, 3, 1, 4, 5]