留言板案例

开发环境

java的jdk:jdk1.8.0_66

java的开发工具：eclipse（eclipse-photon）

数据库：MySQL Server 5.1

Web容器：apache-tomcat-8.5.32

jar包：c3p0-0.9.1.2.jar mysql-connector-java-5.1.6-bin.jar

配置文件

c3p0-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
	<!--默认配置 -->
	<default-config>
		<property name="initialPoolSize">10</property>
		<property name="maxIdleTime">30</property>
		<property name="maxPoolSize">100</property>
		<property name="minPoolSize">10</property>
		<property name="maxStatements">200</property>
	</default-config>

	<!--配置连接池mysql -->
	<named-config name="mysql">
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql://localhost:3306/test</property>
		<property name="user">root</property>
		<property name="password">123456</property>
		<property name="initialPoolSize">10</property>
		<property name="maxIdleTime">30</property>
		<property name="maxPoolSize">100</property>
		<property name="minPoolSize">10</property>
		<property name="maxStatements">200</property>
	</named-config>

</c3p0-config>

注意：将c3p0-config.xml放在src下面

需要的两个表

用户表

用户表（tab_admin）

字段	描述	数据类型	约束	备注
aid	用户编号	int	PK	自动增长
aname	密码	varchar	Not null
password	用户编号	varchar	Not null

留言表

留言表(tab_gestbook)

字段	描述	数据类型	约束	备注
gst_id	用户编号	int	PK	自动增长
aid	用户编号	int	UK
gst_title	留言标题	varchar
gst_content	留言内容	varchar
gst_time	留言时间	timestamp
gst_ip	用户的IP地址	Varchar

流程介绍

a.用户登录成功后，显示留言信息列表。如图：

b.用户点击“我要留言”，显示留言界面。如图：

c.点击“留言”，将数据写入数据库，并将返回到留言列表信息界面。
d.如果用户没有没有登录，则提示用户，需要登录才能查看留言

e．用户登录界面：

项目列表如下图片

控制器包下com.bbs.controller（Servlet）

AdminLoginServlet.java

package com.bbs.controller;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bbs.dao.AdminDao;
import com.bbs.pojo.Admin;

public class AdminLoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	private AdminDao adminDao;

	public AdminLoginServlet() {
		super();
		this.adminDao = new AdminDao();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/html; charset=UTF-8");

//		1.获取用户提交的信息
		String strname = request.getParameter("aname");
		String strpass = request.getParameter("password");

//		2.组织数据信息,调用Dao的业务方法
		Admin admin=new Admin(strname,strpass);
		Admin result=adminDao.login(admin);
		
//		3.根据结果返回到对应的页面或者下个Servlet
		if(result!=null) {
			request.getSession().setAttribute("logined", result);
			response.sendRedirect("ListGestBookServlet");
			return;
		}
		response.sendRedirect("login.jsp");
		return;
	}

}

InsertGestBookServlet.java

package com.bbs.controller;

import java.io.IOException;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bbs.dao.GestbookDao;
import com.bbs.pojo.Admin;
import com.bbs.pojo.Gestbook;

public class InsertGestBookServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private GestbookDao bookDao;

	public InsertGestBookServlet() {
		super();
		this.bookDao = new GestbookDao();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/html; charset=UTF-8");
		
//		1.获取提交的留言数据
//		gst_id	自动增长	default
//		aid		会话中提取
//		gst_title	表单提交过来
//		gst_content	表单提交过来
//		gst_time	当前时间	new Date();
//		gst_ip		请求对象中包含有request.getRemoteAddr()
		Admin admin=(Admin) request.getSession().getAttribute("logined");
		Integer aid=admin.getAid();
		String gst_title=request.getParameter("gst_title");
		String gst_content=request.getParameter("gst_content");
		Date gst_time=new Date();
		String gst_ip=request.getRemoteAddr();
		
//		2.组织数据,通过Dao完成添加留言
		Gestbook book=new Gestbook(aid, gst_title, gst_content, gst_ip, gst_time);
		bookDao.insertGestbook(book);
		
//		3.返回到ListGestBookServlet重新提取所有浏览,并在list.jsp中显示新添加的数据内容
		response.sendRedirect("ListGestBookServlet");
		
	}

}

ListGestBookServlet.java

package com.bbs.controller;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bbs.dao.AdminDao;
import com.bbs.dao.GestbookDao;
import com.bbs.pojo.Gestbook;

public class ListGestBookServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private GestbookDao gestBookDao;
	private AdminDao adminDao;

	public ListGestBookServlet() {
		super();
		this.gestBookDao = new GestbookDao();
		this.adminDao = new AdminDao();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/html; charset=UTF-8");
		
		ArrayList<Gestbook> list=gestBookDao.getAllGestbook();
		request.setAttribute("list", list);
		
//		HashMap以 aid<==>aname 的形式组织所有的数据保存进来.
		HashMap<Integer,String> map=new HashMap<Integer,String>();
		for(Gestbook book:list) {
			Integer aid=book.getAid();
			String aname=adminDao.getNameById(book.getAid());
			map.put(aid, aname);
		}
		request.setAttribute("map", map);
		
		
		this.getServletContext().getRequestDispatcher("/list.jsp").forward(request, response);
		
	}

}

访问数据库包下com.bbs.dao

AdminDao.java

package com.bbs.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import com.bbs.pojo.Admin;
import com.bbs.util.C3P0Utils;

public class AdminDao {
	public Admin login(Admin admin) {
		Admin result=null;
		String sql="select aid,aname,password from tab_admin where aname=? and password=?";
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con = C3P0Utils.getConn();
			ps = con.prepareStatement(sql);
			ps.setString(1, admin.getAname());
			ps.setString(2, admin.getPassword());
			rs=ps.executeQuery();
			if(rs.next()) {
				result=new Admin();
				result.setAid(rs.getInt("aid"));
				result.setAname(rs.getString("aname"));
				result.setPassword(rs.getString("password"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			C3P0Utils.closeJDBC(con, ps, rs);
		}
		return result;
	}

	public String getNameById(Integer id) {
		String sql="select aname from tab_admin where aid=?";
		String result=null;
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con = C3P0Utils.getConn();
			ps = con.prepareStatement(sql);
			ps.setInt(1, id);
			rs=ps.executeQuery();
			if(rs.next()) {
				result=rs.getString("aname");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			C3P0Utils.closeJDBC(con, ps, rs);
		}
		return result;
	}
}

GestbookDao.java

package com.bbs.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Timestamp;
import java.util.ArrayList;

import com.bbs.pojo.Gestbook;
import com.bbs.util.C3P0Utils;
import com.bbs.util.DateUtil;

public class GestbookDao {
//	获取所有的数据列表
	public ArrayList<Gestbook> getAllGestbook(){
		ArrayList<Gestbook> list=new ArrayList<Gestbook>();
		String sql="select * from tab_gestbook";
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con = C3P0Utils.getConn();
			ps = con.prepareStatement(sql);
			rs=ps.executeQuery();
			while(rs.next()) {
				Gestbook book=new Gestbook();
				book.setGst_id(rs.getInt("gst_id"));
				book.setAid(rs.getInt("aid"));
				book.setGst_title(rs.getString("gst_title"));
				book.setGst_content(rs.getString("gst_content"));
				book.setGst_ip(rs.getString("gst_ip"));
				Timestamp temp=rs.getTimestamp("gst_time");
				book.setGst_time(temp);
				list.add(book);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			C3P0Utils.closeJDBC(con, ps, rs);
		}
		return list;
	}
	
	
//	添加新的留言信息
	public int insertGestbook(Gestbook book) {
		int result=0;
		String sql="insert into tab_gestbook values(default,?,?,?,?,?)";
		Connection con=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		try {
			con = C3P0Utils.getConn();
			ps = con.prepareStatement(sql);
			ps.setInt(1, book.getAid());
			ps.setString(2,book.getGst_title());
			ps.setString(3, book.getGst_content());	
			ps.setString(4,DateUtil.getStringByDate(book.getGst_time()));
			ps.setString(5, book.getGst_ip());
			result=ps.executeUpdate();
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			C3P0Utils.closeJDBC(con, ps, rs);
		}
		return result;
	}	
}

实体类包下com.bbs.pojo（entity）

Admin.java

package com.bbs.pojo;

public class Admin {
	private Integer aid;
	private String aname;
	private String password;

	public Admin() {
		super();
	}

	public Admin(String aname, String password) {
		super();
		this.aname = aname;
		this.password = password;
	}

	public Admin(Integer aid, String aname, String password) {
		super();
		this.aid = aid;
		this.aname = aname;
		this.password = password;
	}

	public Integer getAid() {
		return aid;
	}

	public void setAid(Integer aid) {
		this.aid = aid;
	}

	public String getAname() {
		return aname;
	}

	public void setAname(String aname) {
		this.aname = aname;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

}

Gestbook.java

package com.bbs.pojo;

import java.util.Date;

public class Gestbook {
	private Integer gst_id;
	private Integer aid;
	private String gst_title;
	private String gst_content;
	private String gst_ip;
	private Date gst_time;

	public Gestbook() {
		super();
	}

	public Gestbook(Integer aid, String gst_title, String gst_content, String gst_ip, Date gst_time) {
		super();
		this.aid = aid;
		this.gst_title = gst_title;
		this.gst_content = gst_content;
		this.gst_ip = gst_ip;
		this.gst_time = gst_time;
	}

	public Gestbook(Integer gst_id, Integer aid, String gst_title, String gst_content, String gst_ip, Date gst_time) {
		super();
		this.gst_id = gst_id;
		this.aid = aid;
		this.gst_title = gst_title;
		this.gst_content = gst_content;
		this.gst_ip = gst_ip;
		this.gst_time = gst_time;
	}

	public Integer getGst_id() {
		return gst_id;
	}

	public void setGst_id(Integer gst_id) {
		this.gst_id = gst_id;
	}

	public Integer getAid() {
		return aid;
	}

	public void setAid(Integer aid) {
		this.aid = aid;
	}

	public String getGst_title() {
		return gst_title;
	}

	public void setGst_title(String gst_title) {
		this.gst_title = gst_title;
	}

	public String getGst_content() {
		return gst_content;
	}

	public void setGst_content(String gst_content) {
		this.gst_content = gst_content;
	}

	public String getGst_ip() {
		return gst_ip;
	}

	public void setGst_ip(String gst_ip) {
		this.gst_ip = gst_ip;
	}

	public Date getGst_time() {
		return gst_time;
	}

	public void setGst_time(Date gst_time) {
		this.gst_time = gst_time;
	}

}

工具包下com.bbs.util

C3P0Utils.java

package com.bbs.util;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3P0Utils {
	static ComboPooledDataSource dataSource = new ComboPooledDataSource("mysql");

	public static Connection getConn() {
		try {
			Connection conn = dataSource.getConnection();
			return conn;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}
	
	public static void closeJDBC(Connection con,Statement st,ResultSet rs) {
		if(rs!=null) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		if(st!=null) {
			try {
				st.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		
		try {
			if(con!=null && con.isClosed()==false) {
				con.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}

DateUtil.java

package com.bbs.util;

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateUtil {
	public static String getStringByDate(Date date) {
		SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
		return sdf.format(date);
	}
}

WebContent下如图

WEB-INF下的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3/2001/XMLSchema-instance" xmlns="http://java.sun/xml/ns/javaee" xsi:schemaLocation="http://java.sun/xml/ns/javaee http://java.sun/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>BBS-Demo01</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>AdminLoginServlet</display-name>
    <servlet-name>AdminLoginServlet</servlet-name>
    <servlet-class>com.bbs.controller.AdminLoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>AdminLoginServlet</servlet-name>
    <url-pattern>/AdminLoginServlet</url-pattern>
  </servlet-mapping>
  <servlet>
    <description></description>
    <display-name>ListGestBookServlet</display-name>
    <servlet-name>ListGestBookServlet</servlet-name>
    <servlet-class>com.bbs.controller.ListGestBookServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>ListGestBookServlet</servlet-name>
    <url-pattern>/ListGestBookServlet</url-pattern>
  </servlet-mapping>
  <servlet>
    <description></description>
    <display-name>InsertGestBookServlet</display-name>
    <servlet-name>InsertGestBookServlet</servlet-name>
    <servlet-class>com.bbs.controller.InsertGestBookServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>InsertGestBookServlet</servlet-name>
    <url-pattern>/InsertGestBookServlet</url-pattern>
  </servlet-mapping>
</web-app>

WebContent下
insert.jsp

<%@ page language="java" import="com.bbs.pojo.Admin" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="${pageContext.request.contextPath}/InsertGestBookServlet" method="post">
		作者:<input type="text" name="aid" value="<%=((Admin)session.getAttribute("logined")).getAname()%>" readonly="readonly"/><br/><br/>
		主题:<input type="text" name="gst_title"/><br/><br/>
		内容:<input type="text" name="gst_content"/><br/><br/>
		<input type="submit" value="留言"/>
		<input type="reset" value="取消"/>
	</form>
</body>
</html>

list.jsp

<%@ page language="java" import="java.util.*,com.bbs.pojo.Gestbook,com.bbs.util.DateUtil" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<hr/>
	<a href="${pageContext.request.contextPath}/insert.jsp">我要留言</a><br/><br/>
	共15条留言	当前2/10页	第一页最	上一页	下一页	后一页<br/><br/>
	<hr/>
	<%
	ArrayList<Gestbook> list=(ArrayList<Gestbook>)request.getAttribute("list");
	HashMap<Integer,String> map=(HashMap<Integer,String>)request.getAttribute("map");
	for(Gestbook book:list){%>
		用户名:<%=map.get(book.getAid())%>	留言时间:<%=DateUtil.getStringByDate(book.getGst_time())%>		用户IP:<%=book.getGst_ip()%>	<br/>
		主题:<%=book.getGst_title()%><br/>
		内容:<%=book.getGst_content()%><br/>
		<hr/>
	<%}%>
	
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="${pageContext.request.contextPath}/AdminLoginServlet" method="post">
		账号:<input type="text" name="aname"/><br/><br/>
		密码:<input type="text" name="password"/><br/><br/>
		<input type="submit" value="登录"/>
	</form>	
</body>
</html>

执行效果图如下

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java的留言板案例

java的留言板案例

留言板案例

开发环境

java的jdk:jdk1.8.0_66

java的开发工具：eclipse（eclipse-photon）

数据库：MySQL Server 5.1

Web容器：apache-tomcat-8.5.32

jar包：c3p0-0.9.1.2.jar mysql-connector-java-5.1.6-bin.jar

配置文件

需要的两个表

用户表

留言表

流程介绍

项目列表如下图片

控制器包下com.bbs.controller（Servlet）

访问数据库包下com.bbs.dao

实体类包下com.bbs.pojo（entity）

工具包下com.bbs.util

WebContent下如图

执行效果图如下

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标签列表

java的留言板案例

留言板案例

开发环境

java的jdk:jdk1.8.0_66

java的开发工具：eclipse（eclipse-photon）

数据库：MySQL Server 5.1

Web容器：apache-tomcat-8.5.32

jar包：c3p0-0.9.1.2.jar mysql-connector-java-5.1.6-bin.jar

配置文件

需要的两个表

用户表

留言表

流程介绍

项目列表如下图片

控制器包下com.bbs.controller（Servlet）

访问数据库包下com.bbs.dao

实体类包下com.bbs.pojo（entity）

工具包下com.bbs.util

WebContent下如图

执行效果图如下

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