1. Write a program usennuftevalidator.java that ask the user to enter a usemame and checks whether the usemame meets the following criteria:

• the usemame is at least 7 characters lOng
• the usemame contains at least one lowercase letters.
• the usemame contains at least one special character. Allowed special characters are':' ,

For any criterion that is not met print a message. If all the criterias are met display a message 'The usemame is valid!"

Hint: Use the =gins method from the String library for the special characters. To check whether the usemame contains at least one lowercase letter, compare the usemame to the usemame with all uppercase letters. If they are the same, then there is no lowercase letter.

Example Input:

Howdy

Example Output:

The username is less than 7 characters long.
The username does not contain any special characters.

Example Input:

Howdy/

Example Output:

The username is valid!

2. For this problem you will use the stdlib iar for creating a 2D graphics. You will set the dimensions of the screen to be (-1. 1) for the x axis and (-1. 1) for the y axis.

1. Draw the x and y axis. To do this use the method StdDraw. line which takes 4 parameters x0. yO. x1. and y1.
2. Ask the user to enter x and y coordinates of a point.
3. If the coordinates are outside the drawing screen display a message 'Error in the middle of the screen. To display the text use the method StdDraw. text which takes three parameters the x and y coordinate of the text and the message to be displayed.
4. If the coordinates are valid. then if they fall in the
a. first quadrant. draw a filled Circle at the entered point. Use method stdbray.filiedcircie
b. second quadrant, draw a filled Square at the entered point. Use method StdDraw. filledSquare.
c. third quadrant, draw a Square at the entered point. Use method StdDraw.square.
d. fourth quadrant, draw a Circle at the entered point. Use method StdDraw.circle.

The choice of the colors and the size of the geometric shapes is up to you. Draw the shape centered at the coordinates entered by the user. Name the class, DrawShape . j ave.

3. Create a class, NamePrinter java, which will ask user for their name and their output format choice. Assume that a name consists first name and last name with a space in between (FirstName LastName).

Based on the chosen output choice, format their name and display it. Use the switch statement (not if statement) for checking the choice.

Choice 1: Replace the first letter of first name to '_'

Choice 2: If the length of the name (including spaces) is greater than 7 then convert the entire name to uppercase. Otherwise print the name with no changes.

Choice 3: If the length of the name (including spaces) is less than 10 then convert the entire name to lowercase. Otherwise print the name with no changes.

If the choice is not between 1 to 3 display an error message to the user This is not a valid choice!".