javaweb图书商城设计之图书模块(4)

本文接着上一篇图书商城分类模块进行学习，供大家参考，具体内容如下

1、创建相关类

cn.itcast.bookstore.book
domain：book
dao：bookdao
service :bookservice
web.servle：bookservlet

book

public class book {
 private string bid;
 private string bname;
 private double price;
 private string author;
 private string image;
 private category category;
 private boolean del;
}

bookdao

public class bookdao {
 private queryrunner qr = new txqueryrunner();

 /**
 * 查询所有图书
 * @return
 */
 public list<book> findall() {
 try {
 string sql = "select * from book where del=false";
 return qr.query(sql, new beanlisthandler<book>(book.class));
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 /**
 * 按分类查询
 * @param cid
 * @return
 */
 public list<book> findbycategory(string cid) {
 try {
 string sql = "select * from book where cid=? and del=false";
 return qr.query(sql, new beanlisthandler<book>(book.class), cid);
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 /**
 * 加载方法
 * @param bid
 * @return
 */
 public book findbybid(string bid) {
 try {
 /*
 * 我们需要在book对象中保存category的信息
 */
 string sql = "select * from book where bid=?";
 map<string,object> map = qr.query(sql, new maphandler(), bid);
 /*
 * 使用一个map，映射出两个对象，再给这两个对象建立关系！
 */
 category category = commonutils.tobean(map, category.class);
 book book = commonutils.tobean(map, book.class);
 book.setcategory(category);
 return book;
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 /**
 * 查询指定分类下的图书本数
 * @param cid
 * @return
 */
 public int getcountbycid(string cid) {
 try {
 string sql = "select count(*) from book where cid=?";
 number cnt = (number)qr.query(sql, new scalarhandler(), cid);
 return cnt.intvalue();
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 /**
 * 添加图书
 * @param book
 */
 public void add(book book) {
 try {
 string sql = "insert into book values(?,?,?,?,?,?)";
 object[] params = {book.getbid(), book.getbname(), book.getprice(),
  book.getauthor(), book.getimage(), book.getcategory().getcid()};
 qr.update(sql, params);
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 /**
 * 删除图书
 * @param bid
 */
 public void delete(string bid) {
 try {
 string sql = "update book set del=true where bid=?";
 qr.update(sql, bid);
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }

 public void edit(book book) {
 try {
 string sql = "update book set bname=?, price=?,author=?, image=?, cid=? where bid=?";
 object[] params = {book.getbname(), book.getprice(),
  book.getauthor(), book.getimage(), 
  book.getcategory().getcid(), book.getbid()};
 qr.update(sql, params);
 } catch(sqlexception e) {
 throw new runtimeexception(e);
 }
 }
}

bookservice

public class bookservice {
 private bookdao bookdao = new bookdao();

 /**
 * 查询所有图书
 * @return
 */
 public list<book> findall() {
 return bookdao.findall();
 }

 /**
 * 按分类查询图书
 * @param cid
 * @return
 */
 public list<book> findbycategory(string cid) {
 return bookdao.findbycategory(cid);
 }

 public book load(string bid) {
 return bookdao.findbybid(bid);
 }

 /**
 * 　添加图书
 * @param book
 */
 public void add(book book) {
 bookdao.add(book);
 }

 public void delete(string bid) {
 bookdao.delete(bid);
 }

 public void edit(book book) {
 bookdao.edit(book);
 }
}

bookservlet

public class bookservlet extends baseservlet {
 private bookservice bookservice = new bookservice();

 public string load(httpservletrequest request, httpservletresponse response)
 throws servletexception, ioexception {
 /*
 * 1. 得到参数bid
 * 2. 查询得到book
 * 3. 保存，转发到desc.jsp
 */
 request.setattribute("book", bookservice.load(request.getparameter("bid")));
 return "f:/jsps/book/desc.jsp";
 }

 /**
 * 查询所有图书
 * @param request
 * @param response
 * @return
 * @throws servletexception
 * @throws ioexception
 */
 public string findall(httpservletrequest request, httpservletresponse response)
 throws servletexception, ioexception {
 request.setattribute("booklist", bookservice.findall());
 return "f:/jsps/book/list.jsp";
 }

 /**
 * 按分类查询
 * @param request
 * @param response
 * @return
 * @throws servletexception
 * @throws ioexception
 */
 public string findbycategory(httpservletrequest request, httpservletresponse response)
 throws servletexception, ioexception {
 string cid = request.getparameter("cid");
 request.setattribute("booklist", bookservice.findbycategory(cid));
 return "f:/jsps/book/list.jsp";
 }
}

2、查询所有图书

流程：left.jsp（全部分类） -> bookservlet#findall() -> /jsps/book/list.jsp

3、按分类查询图书

流程：left.jsp -> bookservlet#findbycategory() -> list.jsp

4、查询详细信息（加载）

流程：list.jsp（点击某一本书） -> bookservlet#load() -> desc.jsp

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。