一、模糊查询

<!-- 功能1：实现admin.jsp页面中新闻管理模块----模糊查询的搜索功能（根据标题进行模糊查询） -->
				<!-- 
					注意：在没有学习servlet时，模糊查询都是本页面
					问题：当输入关键词后，点击搜索按钮，跳转（1.do处理页面 2.admin.jsp）  admin.jsp
				
				
				 -->
<div style = "width:100%;height:40px;text-align: center;line-height:40px; ">
					<form action = "admin.jsp" method = "post">
						<label>新闻标题</label>
						<!-- autocomplete 关闭自动提示 -->
						<input type = "text" name = "strName" autocomplete="off"/>
						<input type = "submit" value = "搜索"/>
					</form>
				</div>
				
				<%
					//1.运行admin.jsp之后，默认显示所有新闻。
					//2.在输入框中输入关键词点击搜索  跳转到本页面
					//通过request内置对象获取当前模糊查询表单提交的关键词
					
					//编码设置
					request.setCharacterEncoding("utf-8");
					String strName = request.getParameter("strName");
					//搜索的关键词为中文  获取时会出现乱码    通过String类进行编码和解码（得到我们看得懂的中文）
					System.out.println("模糊查询的关键词为:[解决前] "+strName);
					//sql语句
					String sql = "select * from tb_news";
					//第一次运行admin.jsp  strName为null  不能调用任何方法
					if(null!=strName){
						//new String(strName.getBytes("ISO-8859-1"),"utf-8");
						//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");
						//强调  电脑 有些电脑不需要第82行代码。
						//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:[解决后] "+strName);
				
					System.out.println("模糊查询的关键词为:[sql] "+sql);
				%>

二、发布评论

<%@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("<script>alert('评论成功');location.href='newRead.jsp?username="+username+"&nid="+nid+"'</script>");
		}else{
			out.println("<script>alert('评论失败');location.href='newRead.jsp?username="+username+"&nid="+nid+"'</script>");
		}
		
	
	
	%>

三、删除评论

<%@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"%>
 
    <%
    	//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("<script>alert('此评论不是当前用户所评，无法删除');location.href='newRead.jsp?username="+username+"&nid="+nid+"'</script>");
    	}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("<script>alert('删除成功');location.href='newRead.jsp?username="+username+"&nid="+nid+"'</script>");
			}else{
				out.println("<script>alert('删除失败');location.href='newRead.jsp?username="+username+"&nid="+nid+"'</script>");
	    		
			}
			
    		
    		
    	}
    
    %>