I need a java code and use eclipse

1. Write a program that declares a named constant to hold the number of quarts in a gallon (4) [1 gallon = 4 quarts]. Also declare a variable to represent the number of quarts needed for a painting job, and assign an appropriate value, for example, 18. Compute and display the number of gallons and quarts needed for the job. Display explanatory text with the values, for example, A job that needs 18 quarts requires 4 gallons plus 2 quarts. Save the program as QuartsToGallons.java.
2. Convert the QuartsToGallons program to an interactive application. Instead of assigning a value to the number of quarts, accept the value from the user as input. Save the revised program as QuartsToGallonsInteractive.java.

1. Create a class named Circle with fields named radius, diameter, and area. Include a constructor that sets the radius to 1 and calculates the other two values. Also include methods named setRadius() and getRadius(). The setRadius() method not only sets the radius, but it also calculates the other two values. (The diameter of a circle is twice the radius, and the area of a circle is pi multiplied by the square of the radius. Use the Math class PI constant for this calculation.) Save the class as Circle.java.
2. Create a class named TestCircle whose main() method declares several Circle objects. Using the setRadius() method, assign one Circle a small radius value, and assign another a larger radius value. Do not assign a value to the radius of the third circle; instead, retain the value assigned at construction. Display all the values for all the Circle objects. Save the application as TestCircle.java.