A company manufacturing bicycles needs to keep track of its bikes that are being sold in various shops.

Part 1. (4 points) For each Bike object, the information of interest is:

• the code (a string) that identifies the bike;
• the color (a string);
• the minimum weight (in kg) of a person for which the bike is suited (an integer);
• the maximum weight (in kg) of a person for which the bike is suited (an integer).

• creation of a Bike, given its code, color, minimum weight, and maximum weight;
• getCode: that returns the code of the bike;
• getColor: that returns the color of the bike;
• getMinWeight: that returns the minimum weight of the bike;
• getMaxWeight: that returns the maximum weight of the bike.

Solution: class Bike

Part 2. (16 points) For each shop (identified by its name, a string), the bikes available in that shop are stored in a BikePool data structure. A BikePool has a size, which determines the maximum number of bikes it can contain.

Realize a Java class BikePool, to represent BikePool objects, that exports the following functionalities:

• creation of a BikePool, given the name of the shop and the size of the pool; the created BikePool is initially empty (i.e., it contains no bikes);
• getShop: that returns the name of the shop;
• getSize: that returns the size of the pool;
• newBike: that, given a Bike object, inserts it into the bike pool, if a bike object with the same code is not already present in the pool, does nothing otherwise; if the bike pool is full the method does nothing;
• getBike: that, given the code c of a bike, returns the bike object with code c in the bike pool, if such an object is present in the pool, null otherwise;
• removeBike: that, given the code c of a bike, eliminates from the bike pool the bike object with code c, if such an object is present in the pool, does nothing otherwise;
• numBikes: that returns the number of bikes in the pool;
• bikesForWeight: that, given a positive integer h representing the weight of a person, returns an array of strings containing the codes of all bikes in the pool that are suitable for weight h; a bike is suitable for a weight h if h is between the minimum and maximum weights of the bike.

Solution: representation of the objects, skeleton of the class, class BikePool

Part 3. (6 points) Realize a static method ColorsforWeight, client of the class BikePool (i.e., external to such a class) that, given a BikePool object bp, a positive integer h representing the weight of a person, and the name f of a file, writes on the file f the colors of all those bikes in bp that are suitable for weight h.

Solution

Additional files to test the solution: class Main, input file bikes.txt

Part 4. (4 points) Discuss the notions scope and of lifetime of a variable. Emphasize the differences with respect to scop and lifetime between the different types of variables that a Java program may contain.