JSP+Servlet+javabean+mysql实现页面多条件模糊查询（转载）

需求：

一般列表页上面会有一个查询框，有各种的查询条件组合，一般都采用模糊查询方式 ，以下以自己做的实例来说明一下实现方法：

需要实现的界面原型：要满足条件：

1、单选分类，点GO按扭

2、单独输入标题关键字，点GO按扭

3、选择分类，再输入关键字，点GO按扭

我这里用了MVC分层模式来进行的，所以一步步讲解吧，上源码：

因为我一个class里写了很多不同的业务，所以帖代码只帖当前步

dao层：

1 //当前页显示的新闻信息pageNo 当前页码，pagePerCount是每页多少条数据
2     public List getPageNewsList(int pageNo,int pagePerCount,String where);

daoImpl层:

这里方法中加的参数是where,因为我不确定前台可能有几个模糊查询的条件，所以这里只能用个整体的字符串来定义，到时候用StringBuffer来拼就行

这里注意一下字符串拼接加变量的写法

 1 public List getPageNewsList(int pageNo, int pagePerCount,String where) {
 2 List newslist =new ArrayList();  3 String sql = "select d.id,d.title,d.author,d.summary,d.content,d.picPath,d.createDate,d.modifyDate," +  4 "d.createDate,d.categoryId,c.name as categoryname from news_detail as d,news_category as c" +  5 " where c.id=d.categoryId and d.status=1 "+where+"order by d.createDate desc limit ?,?";  6 Object[] params ={(pageNo-1)*pagePerCount,pagePerCount};  7 if(this.getconnection()){  8 ResultSet rs = this.executeQuery(sql, params);  9 try { 10 while(rs.next()){ 11 NewsDetail news = new NewsDetail(); 12 int id = rs.getInt("id"); 13 String title1 = rs.getString("title"); 14 String author =rs.getString("author"); 15 int categoryId = rs.getInt("categoryId"); 16 String categoryname=rs.getString("categoryname"); 17 String summary = rs.getString("summary"); 18 String content = rs.getString("content"); 19 String picPath =rs.getString("picPath"); 20 Timestamp createDate =rs.getTimestamp("createDate"); 21 Timestamp modifyDate =rs.getTimestamp("modifyDate"); 22  news.setId(id); 23  news.setCategoryId(categoryId); 24  news.setAuthor(author); 25  news.setCategoryname(categoryname); 26  news.setContent(content); 27  news.setSummary(summary); 28  news.setPicPath(picPath); 29  news.setCreateDate(createDate); 30  news.setModifyDate(modifyDate); 31  news.setTitle(title1); 32  newslist.add(news); 33 34  } 35 } catch (SQLException e) { 36  e.printStackTrace(); 37 }finally{ 38 this.clossconnection(); 39  } 40  } 41 return newslist; 42 }

service接口：

1 //当前页显示的新闻信息pageNo 当前页码，pagePerCount是每页多少条数据
2         public List getPageNewsList(int pageNo,int pagePerCount,String where);

serviceImpl接口实现类：

因为业务比较简单，所以代码也很简单哈，service只是调一下dao即可

 1 public class NewsServiceImpl implements NewsService {
 2 private NewsDao newsdao =null;  3 public NewsServiceImpl(){  4 newsdao=new NewsDaoImpl();  5 newscategory1 =new NewsCategoryDaoImpl();  6  }  7 public int getNewsCount(String where) {  8 return newsdao.getNewsCount(where);  9  } 10 ｝

以下是重点，套页面JSP+Servlet

newsDetailList.jsp：我把样式那些都省略了，只列出整体的页面框架元素

 1 <div class="main-content-right">  2   3 <div class="main-text-box">  4 <div class="main-text-box-tbg">  5 <div class="main-text-box-bbg">  6 <form name ="searchForm" id="searchForm" action="<%=request.getContextPath() %>/servlet/newsListByLikeServlet" method="post">  7 <div>  8  新闻分类：  9 <select name="categoryId"> 10 <option value="0">全部option> 11 <c:forEach var="category" items="${categorylist }" varStatus="status"> 12 <option value='${category.id }' >${category.name }option> 13 c:forEach> 14 15 16 17 select> 18 新闻标题<input type="text" name="title" id="title" value=''/> 19 <button type="submit" class="page-btn" onclick="javascript:window.location.href='<%=request.getContextPath() %>/servlet/newsListByLikeServlet'">GObutton> 20 <button type="button" onclick="addNews();" class="page-btn">增加button> 21  22 <input type="hidden" id="pageIndex" name="pageIndex" value="1"/> 23 24 <input type="hidden" name="pageSize" value="10"/> 25 26 div> 27 form> 28 <table cellpadding="1" cellspacing="1" class="admin-list"> 29 <thead > 30 <tr class="admin-list-head"> 31 <th align="center">新闻标题th> 32 <th align="center">新闻类别th> 33 <th align="center">作者th> 34 <th align="center">创建时间th> 35 <th align="center">操作th> 36 tr> 37 thead> 38 39 

转载于:https://www.cnblogs.com/HongDunLaoGui/p/7780715.html