Spring第三课,Lombok工具包下载，对应图书管理系统列表和登录界面的后端代码，分层思想

package com.example.demo.demos.web;
 
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import javax.servlet.http.HttpSession;
 
@RequestMapping("/user")
@RestController
public class UserController {
    @RequestMapping("/login")
    public Boolean login(String userName, String password, HttpSession session){
        //校验参数
        if(!StringUtils.hasLength(userName)||!StringUtils.hasLength(password)){
            return  false;
        }
        //验证账号密码是否正确
        //为什么admin放在前面，因为假如userName为NULL，这样他就会报一个空指针错误，常量放在前面，开发习惯
        if("admin".equals(userName)&&"admin".equals(password)){
            //账号密码正确
            //存session,一会在这个地方，记得要去测试一下没有session会怎么样
           session.setAttribute("userName",userName);
            return  true;
        }
        return  false;
    }
 
}

package com.example.demo.demos.web;
 
import lombok.Data;
 
import java.math.BigDecimal;
 
@Data
public class BookInfo {
    private Integer id;
    private String bookName;
    private String author;
    private Integer count;
    private BigDecimal price;
    private String publish;
    //1.表示可借阅，2.不可借阅
    private  Integer status;
    private  String   statusCN;
}

package com.example.demo.demos.web;
 
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
 
@RestController
@RequestMapping("/book")
public class BookController {
    @RequestMapping("/getBookList")
    public List<BookInfo> getBookList() {
        //1.获取图书的数据
        //2.对图书数据进行修改，针对状态码数字（0：有货，1：没货这种）进行改变，把状态码数字转换成中文
        //3.返回数据
        List<BookInfo> bookInfos = mockData();
        for (BookInfo bookInfo : bookInfos) {
            if (bookInfo.getStatus() == 1) {
                bookInfo.setStatusCN("可借阅");
            } else {
                bookInfo.setStatusCN("不可借阅");
            }
        }
        return bookInfos;
    }
 
    private List<BookInfo> mockData() {
        List<BookInfo> bookInfos = new ArrayList<>(15);
        //对于已知数据量，或者大概知道这个集合的数据量时，创建list时，建议指定初始化容量
        for (int i = 0; i < 15; i++) {
            BookInfo bookInfo=new BookInfo();
            bookInfo.setId(i);
            bookInfo.setBookName("图书"+i);
            bookInfo.setAuthor("作者"+i);
            bookInfo.setCount(new Random().nextInt(200));
            bookInfo.setPrice(new BigDecimal(new Random().nextInt(100)));
            bookInfo.setPublish("出版社"+i);
            bookInfo.setStatus(i%5==0?2:1);
            bookInfos.add(bookInfo);
        }
        return bookInfos;
    }
}

package com.example.demo.demos.book.controller;
 
import com.example.demo.demos.book.BookInfo;
import com.example.demo.demos.book.service.BookService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
 
@RestController
@RequestMapping("/book")
public class BookController {
    private BookService bookService=new BookService();
    @RequestMapping("/getBookList")
    public List<BookInfo> getBookList() {
        //1.获取图书的数据
        //2.对图书数据进行修改，针对状态码数字（0：有货，1：没货这种）进行改变，把状态码数字转换成中文
        //3.返回数据
 
        List<BookInfo>bookInfos=bookService.getBookList();
        return bookInfos;
    }
 
 
}

package com.example.demo.demos.book.dao;
 
import com.example.demo.demos.book.BookInfo;
 
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
 
public class BookDao {
    public List<BookInfo> mockData() {
        List<BookInfo> bookInfos = new ArrayList<>(15);
        //对于已知数据量，或者大概知道这个集合的数据量时，创建list时，建议指定初始化容量
        for (int i = 0; i < 15; i++) {
            BookInfo bookInfo=new BookInfo();
            bookInfo.setId(i);
            bookInfo.setBookName("图书"+i);
            bookInfo.setAuthor("作者"+i);
            bookInfo.setCount(new Random().nextInt(200));
            bookInfo.setPrice(new BigDecimal(new Random().nextInt(100)));
            bookInfo.setPublish("出版社"+i);
            bookInfo.setStatus(i%5==0?2:1);
            bookInfos.add(bookInfo);
        }
        return bookInfos;
    }
}

package com.example.demo.demos.book.service;
 
import com.example.demo.demos.book.BookInfo;
import com.example.demo.demos.book.dao.BookDao;
 
import java.util.List;
 
public class BookService {
     private BookDao bookDao=new BookDao();
    public List<BookInfo> getBookList() {
 
        List<BookInfo> bookInfos = bookDao.mockData();
        for (BookInfo bookInfo : bookInfos) {
            if (bookInfo.getStatus() == 1) {
                bookInfo.setStatusCN("可借阅");
            } else {
                bookInfo.setStatusCN("不可借阅");
            }
        }
        return bookInfos;
    }
}