编写高质量和可维护的代码：Java技术栈的最佳实践

public class Person {
    private String firstName;
    private String lastName;
    
    public String getFirstName() {
        return firstName;
    }
    
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    
    public String getLastName() {
        return lastName;
    }
    
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    
    public static final int MAX_COUNT = 10;
}

public interface Shape {
    double calculateArea();
}

public class Rectangle implements Shape {
    private double width;
    private double height;
    
    public double getWidth() {
        return width;
    }
    
    public double getHeight() {
        return height;
    }
    
    public void setWidth(double width) {
        this.width = width;
    }
    
    public void setHeight(double height) {
        this.height = height;
    }
    
    public double calculateArea() {
        return width * height;
    }
}

public class Circle implements Shape {
    private double radius;
    
    public double getRadius() {
        return radius;
    }
    
    public void setRadius(double radius) {
        this.radius = radius;
    }
    
    public double calculateArea() {
        return Math.PI * radius * radius;
    }
}

public class FileReader {
    public String readContent(String fileName) {
        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }
            return sb.toString();
        } catch (IOException e) {
            // 打印异常
            e.printStackTrace();
            return null;
        }
    }
}