The do-while construct in Java is a looping structure designed to repeatedly execute a set of statements as long as a specified condition remains true. Unlike the while loop, the do-while loop guarantees the execution of its body at least once, even if the condition is false from the start.

1. Syntax of do...while Construct in Java:

The do-while construct in Java comes in two forms:

• First Form (using only while keyword):

  while (condition is true) {
      // Statements
  }
  
  

• Second Form (using both do and while keywords):

  do {
      // Statements
  } while (condition is true);
  
  

2. Rules about do...while Construct in Java:

• The while construct initiates the execution of its body only if the condition is true. The statements may not be executed if the condition is false from the start.
• The do-while construct always executes the statements in its body at least once, even if the condition is false initially.
• If there is only one statement in the body, the curly braces can be omitted.

3. Java do...while Examples:

Example 1: Using a while loop to print 10 numbers from 1 to 10:

int i = 1;
while (i <= 10) {
    System.out.println(i);
    i++;
}

Example 2: Utilizing a do-while loop to read input from the command line until an empty string is entered:

String input = null;
do {
    System.out.print("Enter input: ");
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    input = reader.readLine();
    System.out.println("Your input: " + input);
} while (!input.equals(""));

By comprehending the nuances of the do-while construct, you gain a powerful tool for creating robust and flexible loops in your Java programs.