jsp带条件查询
JSP 动作元素:
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jsp:forward |
把请求转到一个新的页面 |
Index.jsp进入servlet
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<body> <jsp:forward page="bookServlet.do" /> </body> |
在每个页面跳转到Servlet添加一个变量(choose),根据操作的不同传递不同的值,来区分用户的操作
Index.jsp
add.jsp
Servlet
- 编写查询
需求：
- 在booklist.jsp页面需要显示所有图书类型
1.需要查询全部图书类型
Booklist.jsp
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<style type="text/css"> div{ width: 800px; height: 600px; margin: 0px auto; border: 1px solid red;}
</style> </head> <body> <div> <h1 style="text-align: center;">图书借阅系统</h1> <form action="bookServlet.do" method="post" style="text-align: center;" > 图书分类<select name="booktypeid"> <option value="0">全部</option> </select> 图书名称<input type="text" name="bookname"> 是否借阅<select name="borrow"> <option value="-1">请选择</option> <option value="0">未借阅</option> <option value="1">已借阅</option> </select> <input type="hidden" name="choose" value="1"> <input type="hidden" name="pageno" value="1"> <input type="submit" value="查询">
</form> </div> </body> |
Servlet中查询的代码编写
查询图书类型
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/** * 查询图书类型 * @param request * @param response * @throws ServletException * @throws IOException */ protected void queryBookType(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //调用service层的方法 List<BookType> bookTypes= bookTypeService.queryAll(); //存 HttpSession session=request.getSession(); session.setAttribute("bookTypes",bookTypes );
} |
三层编写
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public class BookTypeDaoImpl implements BookTypeDao {
private QueryRunner queryRunner=C3P0Util.getQueryRunner();
@Override public List<BookType> queryAll() { String sql="SELECT * from book_type"; List<BookType> bookTypes=null; try { bookTypes= queryRunner.query(sql,new BeanListHandler<BookType>(BookType.class)); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return bookTypes; }
} |