JavaWeb-06 (项目案例3)

一.项目模糊查询

				
				

					

						新闻标题
						
						
					
				
				
				<%
					//编码设置
					request.setCharacterEncoding("utf-8");
					String strName = request.getParameter("strName");
					//sql语句
					String sql = "select * from tb_news";
					if(strName != null){
						//将指定编码的字符串进行解码  通过getBytes("编码")   构造函数new String()编码
						strName = new String(strName.getBytes("ISO-8859-1"),"utf-8");
						//sql语句拼接模糊查询
						sql+=" where ntitle like '%"+strName+"%'";
					}
					System.out.println("模糊查询的关键词为:[sql] "+sql);
				%>

二.绑定index页面的主题和新闻

					

						
 
						 全部 
						<%
						//加载驱动
						Class.forName("oracle.jdbc.driver.OracleDriver");
						//建立连接
						String url = "jdbc:oracle:thin:@localhost:1521:orcl";
						Connection conn = DriverManager.getConnection(url, "scott", "123");
				    	//sql
				    	String sql = "select * from tb_news_theme";
				    	PreparedStatement ps = conn.prepareStatement(sql);
						ResultSet rs = ps.executeQuery();
						//sql  select count(*) from tb_news_theme
						int count = 1;
						while(rs.next()){
							count++;
							out.println(" "+rs.getString(2)+"  ");
							//11 就是总记录数
							if(count%11==0){
								out.println("
");
							}
						}
						%>
						
					
					
					<%
						username = request.getParameter("username");
						String tid  = request.getParameter("ntid");
						if(null!=tid){//说明点击了主题分类
							//根据点击的主题分类进行查询  where 条件
							sql = "select * from tb_news where ntid = "+Integer.valueOf(tid);
						}else{//第一次进来，没有点击主题分类
							sql = "select * from tb_news";//查询所有新闻
						}
					%>

三.绑定评论,删除评论

					
					
					<%
						//定义所谓变量（新闻标题，发布时间，点击量，新闻内容等等）
						String ntitle = "";//标题
						String ndate = "";//发布时间
						String nauthor = "";//作者
						String ncontent = "";//内容
						int ncount = 0;//点击量
					
						
						//2.获取id
						String id = request.getParameter("nid");
						//转换
						int nid = 0;
						if(null!=id){
							nid = Integer.valueOf(id);
						}
						//3.获取数据
						//加载驱动
						Class.forName("oracle.jdbc.driver.OracleDriver");
						//建立连接
						Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "scott","123");
						//sql语句
						String sql = "select * from tb_news where nid = ?";
						//将sql语句传入方法返回执行对象
						PreparedStatement ps = conn.prepareStatement(sql);
						ps.setInt(1, nid);
						//返回结果集对象
						ResultSet rs = ps.executeQuery();
						//if改造
						if(rs.next()){
							ntitle = rs.getString(3);
							ndate = rs.getString(8);
							nauthor = rs.getString(4);
							ncontent = rs.getString(6);
							ncount = rs.getInt(9);
						}
					%>
				
				
				
					

						

							

								
<%=ntitle %>
								       
								       
								       
								    点击量 <%=ncount %>
							
							

								

									

								
							
							

								
<%=ndate %>
								
<%=nauthor %> 
							
							

								

							
							

								
 <%=ncontent %> 
							
							

								

									

								
							
						
					
					

						
							
							<%
								//定义一个变量存储指定新闻的评论数
								int commentCount = 0;
								//1.求指定新闻的评论数判断
								sql ="select count(*) from tb_comment where cnid = ?";
								ps = conn.prepareStatement(sql);
								ps.setInt(1, nid);
								rs = ps.executeQuery();
								if(rs.next()){
									commentCount = rs.getInt(1);
								}
								
								if(commentCount!=0){
									//遍历所有的评论
									sql ="select * from tb_comment where cnid = ?";
									ps = conn.prepareStatement(sql);
									ps.setInt(1, nid);
									rs = ps.executeQuery();
									while(rs.next()){
										sql = "select * from tb_news_users where userid = ?";
										ps = conn.prepareStatement(sql);
										ps.setInt(1, rs.getInt(2));
										ResultSet rs2 = ps.executeQuery();
										String uname = "";
										if(rs2.next()){
											uname = rs2.getString(2);
										}
										
										out.println("");
										out.println("");
										out.println("");
										out.println("");
										out.println("");
										out.println("");
									}
									
									
								}else{
									out.println("");
								}
							
							%>
						
							
");
										out.println("用户名:"+uname+"
");
										
										out.println("评论内容:"+rs.getString(5));
										out.println("    删除
");
										out.println("评论时间:"+rs.getString(6)+"
");
										out.println("
");
										out.println(" ");
										out.println("
 暂无评论！ 

								

									

								
							
						
					
					

						

							
							
							
							

								

									
 评 论 
								
								

									
 用户名： 
									

										IP：
										
									
								
								

									

									
								
								

								
							
						
					
				
			

//跳转的doComment.jsp页面 <%@page import="java.text.SimpleDateFormat"%> <%@page import="java.util.Date"%> <%@page import="java.sql.ResultSet"%> <%@page import="java.sql.PreparedStatement"%> <%@page import="java.sql.DriverManager"%> <%@page import="java.sql.Connection"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% //1.设置编码 request.setCharacterEncoding("utf-8"); //获取数据 //评论编号 int cid = 0;//定义一个变量保存最终的id //链接数据库查询到最大的id 最后+1 //加载驱动 Class.forName("oracle.jdbc.driver.OracleDriver"); //建立连接 String url = "jdbc:oracle:thin:@localhost:1521:orcl"; Connection conn = DriverManager.getConnection(url, "scott", "123"); String sql = "select nvl(max(cid),0) from tb_comment"; PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); if(rs.next()){ cid = rs.getInt(1)+1; } //out.println("cid = "+cid); //用户编号 int cuserid = 0; String username = request.getParameter("username"); //根据用户名查找到该用户的编号 sql = "select * from tb_news_users where username = ?"; ps = conn.prepareStatement(sql); ps.setString(1,username); rs = ps.executeQuery(); if(rs.next()){ cuserid = rs.getInt(1); } //新闻编号 int nid = Integer.valueOf(request.getParameter("nid")); //ip地址 String cip = request.getParameter("cip"); //内容 String ccontent = request.getParameter("ccontent"); //时间 Date date = new Date(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String cdate = sdf.format(date); //发表评论 sql = "insert into tb_comment values(?,?,?,?,?,to_date(?,'yyyy-mm-dd hh24:mi:ss'))"; ps = conn.prepareStatement(sql); ps.setInt(1, cid); ps.setInt(2, cuserid); ps.setInt(3, nid); ps.setString(4, cip); ps.setString(5, ccontent); ps.setString(6, cdate); int n = ps.executeUpdate(); if(n>0){ out.println(""); }else{ out.println(""); } %> //删除评论 <% //删除评论 //设置编码 request.setCharacterEncoding("utf-8"); //获取用户名 String username = request.getParameter("username"); //加载驱动 Class.forName("oracle.jdbc.driver.OracleDriver"); //建立连接 String url = "jdbc:oracle:thin:@localhost:1521:orcl"; Connection conn = DriverManager.getConnection(url, "scott", "123"); int cuserid = 0; String sql = "select * from tb_news_users where username = ?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, username); ResultSet rs = ps.executeQuery(); if(rs.next()){ cuserid = rs.getInt(1); } //获取cid String id = request.getParameter("cid"); int cid = 0; if(null!=id){ cid = Integer.valueOf(id); } int cid_cuserid = 0; //根据cid进行查找 cuserid int nid = 0;//保存新闻编号 //sql sql = "select * from tb_comment where cid = ?"; ps = conn.prepareStatement(sql); ps.setInt(1, cid); rs = ps.executeQuery(); if(rs.next()){ cid_cuserid = rs.getInt(2); nid = rs.getInt(3); } if(cuserid!=cid_cuserid){//不是当前登录用户所评论的内容 //out.println("不是当前登录用户的评论内容"); out.println(""); }else{ //out.println("是当前登录用户的评论内容"); //根据当前登录的用户以及对应的评论编号进行删除 sql = "delete from tb_comment where cuserid = ? and cid = ?"; ps = conn.prepareStatement(sql); ps.setInt(1, cid_cuserid); ps.setInt(2, cid); int n = ps.executeUpdate(); if(n>0){ out.println(""); }else{ out.println(""); } } %>