Bubble sort is a simple sorting algorithm that repeatedly compares adjacent elements in an array and swaps them if they are in the wrong order. It continues this process until the array is sorted in ascending or descending order.

Here is an example of how to implement bubble sort in Java:

public class Main {
  public static void main(String[] args) {
    // Create an array of integers
    int[] numbers = { 5, 2, 7, 1, 4 };

    // Sort the array using bubble sort
    bubbleSort(numbers);

    // Print the sorted array
    for (int number : numbers) {
      System.out.print(number + " ");
    }
    // prints "1 2 4 5 7 "
  }

  // Bubble sort method
  public static void bubbleSort(int[] numbers) {
    // Flag to indicate if a swap was made in the current pass
    boolean swapped;

    do {
      // Set the flag to false
      swapped = false;

      // Loop through the array
      for (int i = 0; i < numbers.length - 1; i++) {
        // If the current element is greater than the next element, swap them
        if (numbers[i] > numbers[i + 1]) {
          int temp = numbers[i];
          numbers[i] = numbers[i + 1];
          numbers[i + 1] = temp;

          // Set the flag to true
          swapped = true;
        }
      }
    } while (swapped); // Repeat the process until no swaps are made
  }
}

This code defines a bubbleSort() method that uses a do-while loop to repeatedly compare and swap adjacent elements in the array until it is sorted. It then prints the sorted array to the console.

Keep in mind that bubble sort is not a very efficient sorting algorithm, especially for large arrays, and there are faster sorting algorithms available such as quicksort and mergesort.