A Java while loop is a looping construct which continually executes a block of statements while a condition remains true.

The syntax of a while loop in Java is:

 while (expression) {
   statement
}

Here is a Java while loop that prints the numbers 1 through 10.

 int loopvar = 1;                 // Declare and initialize the loop counter
while (loopvar <= 10) {          // Test and loop
   System.out.println(loopvar);  // Print the variable
   loopvar = loopvar + 1;        // Increment the loop counter
}