Jsp應用實訓二

文章目錄

Servlet代碼演示

package cn.javabs.store.servlet;

import cn.javabs.store.entity.Category;
import cn.javabs.store.service.CategoryService;
import cn.javabs.store.service.impl.CategoryServiceImpl;
import com.alibaba.druid.sql.visitor.functions.If;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.text.EditorKit;
import java.io.IOException;
import java.util.List;

/**
 * 類目的Servlet
 */
@WebServlet("/categoryServlet")
public class CategoryServlet extends HttpServlet {

    //實例化CategoryService
    CategoryService categoryService = new CategoryServiceImpl();

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // 0.在本方法內部進行分別調用如下分類操作的方法
        // ring methodName = "addCategory";
        // 去接收index.jsp頁面中的methodName參數
        String methodName = request.getParameter("methodName");
        // 1.如果字符串"addCategory"等於methodName的值（內容）
        if ("addCategory".equals(methodName)) {
            addCategory(request, response);
            // 2.如果字符串"delCategory"等於methodName的值（內容）
        } else if ("delCategory".equals(methodName)) {
            delCategory(request, response);
            // 3.如果字符串"editCategory"等於methodName的值（內容）
        } else if ("editCategory".equals(methodName)) {
            editCategory(request, response);
            // 4.如果字符串"findAllCategories"等於methodName的值（內容）
        } else if ("findAllCategories".equals(methodName)) {
            findAllCategories(request, response);
        } else if ("editCategoryView".equals(methodName)) {
            editCategoryView(request, response);
        }
        // 5.如果methodName的值（內容）沒有匹配的方法，則執行下方輸入語句
        else {
            System.out.println("哥們，你要的方法不存在，檢查是否單詞有誤！");
        }
    }

//-------------------------------------------------------------------------------------------------------------------------------------------------------

    /**
     * 查詢全部分類
     */
    public void findAllCategories(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List<Category> categoryList = categoryService.findAllCategries();
        System.out.println(categoryList);
        request.setAttribute("list", categoryList); //list是一個標記、記號
        request.getRequestDispatcher("/categoryList.jsp").forward(request, response);
    }

    /**
     * 根據id指示查詢
     */
    public void findCategoryById(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Category category = categoryService.findCategoryById(2);
        System.out.println("因爲index.jsp訪問了頁面中查詢全部的方法，內容：" + category);
    }

    /**
     * 添加分類
     */
    public void addCategory(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 接受前臺的參數
        String cname = request.getParameter("cname");

        Category category = new Category();
        category.setCid(null); //因爲數據庫會自動生成
        //category.setCname("內存卡"); //目前的數據是 寫死的 不是前臺傳遞過來的
        category.setCname(cname); //目前的數據是 寫活的 是前臺傳遞過來的cname
        int rowNumber = categoryService.addCategory(category);
        if (rowNumber > 0) {
            System.out.println("插入成功！");
        } else {
            System.out.println("插入失敗！");
        }
    }

    /**
     * 修改分類 之 數據回顯
     */
    private void editCategoryView(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String cid = request.getParameter("cid");
        int id = Integer.parseInt(cid);//將 "3" 轉爲 3
        Category category = categoryService.findCategoryById(id);
        // 數據回顯 同時顯示 所有分類列表
        List<Category> categoryList = categoryService.findAllCategries();
        if (category != null){
            request.setAttribute("data",category);
            if (categoryList.size()>0 && categoryList != null){
                request.setAttribute("list",categoryList);
            }
            request.getRequestDispatcher("/categoryList.jsp").forward(request,response) ;
            }else{
                request.setAttribute("data","修改失敗");
                request.getRequestDispatcher("/message.jsp").forward(request,response);
            }
        }

    /**
     * 修改分類
     */
    public void editCategory(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String cid = request.getParameter("cid");
        String cname = request.getParameter("cname");
        int id = Integer.parseInt(cid);

        Category category = new Category();
        category.setCid(id);
        category.setCname(cname);
        int rowNumber = categoryService.editCategory(category);
        if (rowNumber > 0) {
            System.out.println("修改成功！");
            response.getWriter().write("修改成功！");//在頁面中顯示結果
        } else {
            System.out.println("修改失敗！");
        }
    }

    /**
     * 刪除分類
     */
    public void delCategory(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String cid = request.getParameter("cid"); //cid = 3
        int id = Integer.parseInt(cid); // 字符串 轉爲 整數
        int rowNumber = categoryService.delCategory(id); //需要的類型是Integer(int)整數
        if (rowNumber > 0) {
            System.out.println("刪除成功！");
        } else {
            System.out.println("刪除失敗！");
        }
    }
}

商品類的實體類

Phone

package cn.javabs.store.entity;

public class Phone {
    private Integer pid; //商品的編號
    private String pname; //商品的名稱
    private String pdescription; //商品描述
    private double price; //單價
    private Integer stock; //庫存
    private String photoPath; //圖片路徑
    private String photoName;
    private Category category; //分類

    @Override
    public String toString() {
        return "Phone{" +
                "pid=" + pid +
                ", pname='" + pname + '\'' +
                ", pdescription='" + pdescription + '\'' +
                ", price=" + price +
                ", stock=" + stock +
                ", photoPath='" + photoPath + '\'' +
                ", photoName='" + photoName + '\'' +
                ", category=" + category +
                '}';
    }

    public Phone(Integer pid, String pname, String pdescription, double price, Integer stock, String photoPath, String photoName, Category category) {
        this.pid = pid;
        this.pname = pname;
        this.pdescription = pdescription;
        this.price = price;
        this.stock = stock;
        this.photoPath = photoPath;
        this.photoName = photoName;
        this.category = category;
    }

    public Phone() {super();}

    public Integer getPid() { return pid;}

    public void setPid(Integer pid) {this.pid = pid;}

    public String getPname() {return pname;}

    public void setPname(String pname) {this.pname = pname;}

    public String getPdescription() {return pdescription;}

    public void setPdescription(String pdescription) {this.pdescription = pdescription;}

    public double getPrice() {return price;}

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

    public Integer getStock() {return stock;}

    public void setStock(Integer stock) { this.stock = stock;}

    public String getPhotoPath() {return photoPath;}

    public void setPhotoPath(String photoPath) { this.photoPath = photoPath;}

    public String getPhotoName() { return photoName;}

    public void setPhotoName(String photoName) {this.photoName = photoName;}

    public Category getCategory() {return category;}

    public void setCategory(Category category) { this.category = category;}
}

設計通用類 Page

Page

package cn.javabs.store.commons;

import java.util.List;

public class Page {
    private List records;       // 查詢到的List中的數據 比如說，查詢到的前5條數 據
    private int totalItems;     //總條數 共有多少條
    private int currentPage;    //當前是第幾頁
    private int totalPage;      //共有多少頁
    private int startIndex;     // 開始索引值
    private int pageSize = 5;   //當前頁面有5條數 | 注意: 一般網頁有 10 條
    private int prePageNum;     // 上一頁
    private int nextPageNum;    //下一頁

/*------------------有參數的構造方法(totalItems,currentPage)------------------ -----*/
    /**
     * 根據已知的 總條數totalItems 可以推算出 總頁數totalPage
     */
    public Page(int totalItems, int currentPage) {
        this.totalItems = totalItems;
        this.currentPage = currentPage;
        // 條件: otalItems % pageSize == 0
        // | 滿足條件： totalItems / pageSize | 不滿 足條件： totalItems / pageSize +1
        totalPage = totalItems % pageSize == 0 ? totalItems / pageSize : totalItems / pageSize + 1;
        startIndex = (currentPage-1)* pageSize;
    }
    /*------------------GetterAndSetter方法-----------------------*/

    public List getRecords() {
        return records;
    }

    public void setRecords(List records) {
        this.records = records;
    }

    public int getTotalItems() {
        return totalItems;
    }

    public void setTotalItems(int totalItems) {
        this.totalItems = totalItems;
    }

    public int getCurrentPage() {
        return currentPage;
    }

    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }

    public int getTotalPage() {
        return totalPage;
    }

    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }

    public int getStartIndex() {
        return startIndex;
    }

    public void setStartIndex(int startIndex) {
        this.startIndex = startIndex;
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    /**
     * 獲取上一頁的頁碼
     */
    public int getPrePageNum() {
        // 判斷當前頁面是不是第一頁 如果是第一頁，顯示1 如果不是第一頁，顯示當前頁面減一
        prePageNum = currentPage - 1 > 0 ? currentPage - 1 : 1;
        return prePageNum;
    }

    public void setPrePageNum(int prePageNum) {
        this.prePageNum = prePageNum;
    }

    /**
     * 獲取下一頁的頁碼
     */
    public int getNextPageNum() {
        // 3 = 3+1 >3? 3(滿足表達式) : 3+1(不滿足表達式)
        // 3 = 2+1 >3? 3(滿足表達式) : 2+1(不滿足表達式)
        // 2 = 1+1 >3? 3(滿足表達式) : 1+1(不滿足表達式)
        nextPageNum = currentPage + 1 > totalPage ? totalPage : currentPage+ 1 ;
        return nextPageNum;
    }

    public void setNextPageNum(int nextPageNum) {
        this.nextPageNum = nextPageNum;
    }
}

商品的數據訪問層接口設計 dao

PhoneDao

package cn.javabs.store.dao;

import cn.javabs.store.entity.Phone;

import java.util.List;

public interface PhoneDao {
    
    //添加商品
    int add(Phone phone);
    
    //刪除商品
    int del(Integer pid);
    
    //修改商品
    int update(Phone phone);
    
    // 指定id查詢
    Phone findById(Integer pid);

    //查詢所有商品
    List<Phone> findAll(int startIndex , int pageSize);

    //查詢總記錄條數（數據庫共有幾條數據）
    int findTotalItems();
}

商品的數據訪問層接口的實現類設計 dao.impl

PhoneDaoImpl

package cn.javabs.store.dao.impl;

import cn.javabs.store.dao.PhoneDao;
import cn.javabs.store.entity.Phone;
import cn.javabs.store.util.DruidUtil;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import java.sql.SQLException;
import java.util.List;

/**
 * 商品的Dao接口的impl實現類設計
 */
public class PhoneDaoImpl implements PhoneDao {
    // 增刪改：採用update方法 | 查 ：採用query方法
    QueryRunner qr = new QueryRunner(DruidUtil.getDataSource());

    /**
     * 添加商品
     */
    @Override
    public int add(Phone phone) {
        int number = 0;
        try {
            number = qr.update("insert into phone(pid,pname,pdescription,price,stock,photoPath,photoName,cid)"
            +"values(null,?,?,?,?,?,?,?)",
                    phone.getPid(),
                    phone.getPname(),
                    phone.getPdescription(),
                    phone.getPrice(),
                    phone.getStock(),
                    phone.getPhotoPath(),
                    phone.getPhotoName(),
                    phone.getCategory().getCid()
            );
            return number;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 刪除商品
     */
    @Override
    public int del(Integer pid) {
        try {
            int number = qr.update("delete from phone where pid = ?",pid);
            return number;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 修改商品
     */
    @Override
    public int update(Phone phone) {
        int number = 0;
        try {
            number = qr.update("update phone set pname=?,pdescription=?,price=?,stock=?,photoPath=?,photoName=?,cid=? where pic=?",
                    phone.getPname(),
                    phone.getPdescription(),
                    phone.getPrice(),
                    phone.getStock(),
                    phone.getPhotoPath(),
                    phone.getPhotoName(),
                    phone.getCategory().getCid(),
                    phone.getPid()
            );
            return number;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 根據指定查詢
     */
    @Override
    public Phone findById(Integer pid) {
        // 第一種寫法： 拆解法
        // Class tel = Phone.class;
        // ResultSetHandler rsh = new BeanHandler(tel);
        // Phone phone = (Phone) queryRunner.query("select * from phone where pid=?",rsh,pid);
        // 第二種寫法： 合併法
        Phone phone = null;
        try {
            phone = qr.query("select * from phone where pid=?",new BeanHandler<>(Phone.class),pid);
            return phone;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 查詢所有商品（參數有兩個）
     */
    @Override
    public List<Phone> findAll(int startIndex, int pageSize) {
        try {
            List<Phone> list = qr.query("select * from phone limit ?,?",new BeanListHandler<>(Phone.class),
                    startIndex,pageSize);
            return list;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }

    }

    /**
     * 查詢總記錄條數（數據庫共有幾條數據）
     */
    @Override
    public int findTotalItems() {
        long longNumber = 0;
        try {
            longNumber = qr.query("select count(*) from phone",new ScalarHandler<>(1));
            int number = longNumber.intValue();
            return number;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}

商品的業務邏輯層接口設計 service

PhoneService

package cn.javabs.store.service;

import cn.javabs.store.commons.Page;
import cn.javabs.store.entity.Phone;

public interface PhoneService {
    //查詢全部
    Page findAllPhones(String pageNum);

    //根據商品的編號查詢商品
    Phone findPhoneByPid(Integer pid);

    //添加商品
    int addPhone(Phone phone);

    //修改商品
    int editPhone(Phone phone);

    //刪除商品
    int delPhone(Integer pid);
}

商品的業務邏輯層接口的實現類設計 service.impl

PhoneServiceImpl

package cn.javabs.store.service.impl;

import cn.javabs.store.commons.Page;
import cn.javabs.store.dao.PhoneDao;
import cn.javabs.store.entity.Phone;
import cn.javabs.store.service.PhoneService;

/**
 * 商品的service接口的實現類設計
 */
public class PhoneServiceImpl implements PhoneService {
    /**
     * 查詢全部
     */
    @Override
    public Page findAllPhones(String pageNum) {
        return null;
    }

    /**
     * 根據商品的編號查詢商品
     */
    @Override
    public Phone findPhoneByPid(Integer pid) {
        return null;
    }

    /**
     * 添加商品
     */
    @Override
    public int addPhone(Phone phone) {
        return 0;
    }

    /**
     * 修改商品
     */
    @Override
    public int editPhone(Phone phone) {
        return 0;
    }

    /**
     * 刪除商品
     */
    @Override
    public int delPhone(Integer pid) {
        return 0;
    }
}

Jsp應用實訓二

文章目錄

Servlet代碼演示

商品類的實體類

Phone

設計通用類 Page

Page

商品的數據訪問層接口設計 dao

PhoneDao

商品的數據訪問層接口的實現類設計 dao.impl

PhoneDaoImpl

商品的業務邏輯層接口設計 service

PhoneService

商品的業務邏輯層接口的實現類設計 service.impl

PhoneServiceImpl

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