1.entity(Book类)

public class Book {
    private Integer id;
    private String name;
    private Double pice;

    public  Book(){}
    public Book(Integer id, String name, Double pice) {
        this.id = id;
        this.name = name;
        this.pice = pice;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Double getPice() {
        return pice;
    }

    public void setPice(Double pice) {
        this.pice = pice;
    }

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pice=" + pice +
                '}';
    }
}

2.dao(BookDAO)

@Component
public class BookDAO {
    public List<Book> getBooks(){
        List<Book> books = new ArrayList <>();
        books.add(new Book(1,"stringboot",88.7));
        books.add(new Book(1,"stringboot",88.7));
        books.add(new Book(1,"stringboot",88.7));
        return books;
    }
}

3.Controller(BookController)

@RestController
public class BookController {
   /**
    *
    */
   //注入dao实例

   @Resource
   private BookDAO bookDAO;
   @RequestMapping(value = "/books" ,method = RequestMethod.GET)
 public List<Book> getBooks(){
       return bookDAO.getBooks();
   }
}