图书分类查询 Demo

ゞ浴缸里的玫瑰 2021-06-22 15:36 438阅读 0赞

## 视频演示： ##

JavaWeb实现

## 源码下载 ##

[资源下载][Link 1] https://download.csdn.net/download/u014565127/12130742

## 目录结构s ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ1NjUxMjc_size_16_color_FFFFFF_t_70]

## 核心代码展示 ##

1.  link.jsp
    
        <body>
            <h1>链接页面</h1>
            <a href="<c:url value='/BookServlet?method=findAll'/>">查询所有分类</a><br>
            <a href="<c:url value='/BookServlet?method=findByCategory&category=1'/>">查询SE分类</a><br>
            <a href="<c:url value='/BookServlet?method=findByCategory&category=2'/>">查询EE分类</a><br>
            <a href="<c:url value='/BookServlet?method=findByCategory&category=3'/>">查询框架分类</a><br>
          </body>
2.  show.jsp
    
        <body>
        	<h1 align="center">图书列表</h1>
        	<table align="center" border="1" width="50%">
        		<tr>
        			<th>书名</th>
        			<th>单价</th>
        			<th>分类</th>
        		</tr>
        		<c:forEach items="${bookList }" var="book">
        			<tr>
        				<td>${book.bname }</td>
        				<td>${book.price }</td>
        				<c:choose>
        					<c:when test="${book.category eq 1 }">
        						<td style="color:red">JavaSE</td>
        					</c:when>
        					<c:when test="${book.category eq 2 }">
        						<td style="color:blue">JavaEE</td>
        					</c:when>
        					<c:when test="${book.category eq 3 }">
        						<td style="color:green">JavaFramework</td>
        					</c:when>
        				</c:choose>
        			</tr>
        		</c:forEach>
        	</table>
        </body>
3.  BookServlet
    
        public class BookServlet extends BaseServlet { 
        	private BookDao bookDao = new BookDao();
        
        	public String findAll(HttpServletRequest request,
        			HttpServletResponse response) throws ServletException, IOException { 
        		request.setAttribute("bookList", bookDao.findAll());
        		return "/show.jsp";
        	}
        
        	public String findByCategory(HttpServletRequest request,
        			HttpServletResponse response) throws ServletException, IOException { 
        		String value =request.getParameter("category");
        		int category = Integer.parseInt(value);
        		request.setAttribute("bookList", bookDao.findByCategory(category));
        		return "/show.jsp";
        	}
        }
4.  BookDao
    
        public class BookDao { 
        	private QueryRunner qr = new TxQueryRunner();
        
        	public List<Book> findAll() { 
        		try { 
        			String sql = "select * from t_book";
        			return qr.query(sql, new BeanListHandler<Book>(Book.class));
        		} catch (SQLException e) { 
        			throw new RuntimeException(e);
        		}
        	}
        
        	public List<Book> findByCategory(int category) { 
        		try { 
        			String sql = "select * from t_book where category=?";
        			return qr.query(sql, new BeanListHandler<Book>(Book.class),
        					category);
        		} catch (SQLException e) { 
        			throw new RuntimeException(e);
        		}
        	}
        }
5.  Book.java
    
        package com.veeja.book.domain;
        
        public class Book { 
        	private String bid;
        	private String bname;
        	private double price;
        	private int category;
        
        	public String getBid() { 
        		return bid;
        	}
        
        	public void setBid(String bid) { 
        		this.bid = bid;
        	}
        
        	public String getBname() { 
        		return bname;
        	}
        
        	public void setBname(String bname) { 
        		this.bname = bname;
        	}
        
        	public double getPrice() { 
        		return price;
        	}
        
        	public void setPrice(double price) { 
        		this.price = price;
        	}
        
        	public int getCategory() { 
        		return category;
        	}
        
        	public void setCategory(int category) { 
        		this.category = category;
        	}
        
        	public String toString() { 
        		return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price
        				+ ", category=" + category + "]";
        	}
        	
        }

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END.

[Link 1]: https://download.csdn.net/download/u014565127/12130742
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ1NjUxMjc_size_16_color_FFFFFF_t_70]: /images/20210615/c6787c95bee64cfdaea4344dccda83f8.png