用Java代码实现单一职责原则课堂Book案例
设我们有一个Book类，表示一本书，其中包含书的名称、作者和价格。我们可以按照单一职责原则将其分解为三个类：Book、Author和Price。
Book类负责维护书的名称、作者和价格，同时提供一些查询和修改方法。
```java
public class Book {
private String name;
private Author author;
private Price price;
public Book(String name, Author author, Price price) {
this.name = name;
this.author = author;
this.price = price;
}
public String getName() {
return name;
}
public Author getAuthor() {
return author;
}
public Price getPrice() {
return price;
}
public void setName(String name) {
this.name = name;
}
public void setAuthor(Author author) {
this.author = author;
}
public void setPrice(Price price) {
this.price = price;
}
}
```
Author类负责维护书的作者信息。
```java
public class Author {
private String name;
public Author(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
```
Price类负责维护书的价格信息。
```java
public class Price {
private double value;
public Price(double value) {
this.value = value;
}
public double getValue() {
return value;
}
public void setValue(double value) {
this.value = value;
}
}
```
通过这种方式，我们将Book类的职责分解为三个类，每个类都只负责自己的职责。这样可以使代码更加清晰、易于维护和扩展。
