controller类

BookController

package com.springboot.quickstart.controller;

import com.springboot.quickstart.dao.BookDAO;
import com.springboot.quickstart.entity.Book;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

@RestController
public class BookController {
    @Resource
    private BookDAO bookDAO;

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

DAO类

BookDAO

package com.springboot.quickstart.dao;

import com.springboot.quickstart.entity.Book;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;

@Component
public class BookDAO {
    public List<Book> getBooks(){
        List<Book> books = new ArrayList<>();
        books.add(new Book(1,"Spring Boot实战",88.7));
        books.add(new Book(2,"Spring MVC",97.1));
        books.add(new Book(3,"从入门到精通",81.7));
        return books;
    }

}

实体类（entity）

Book

package com.springboot.quickstart.entity;

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

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

    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 getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }
}

最后运行即可