mvc2项目实践
删除功能：
创建DeleteNewsServlet
@WebServlet("/deleteServlet")
public class DeleteNewsServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public DeleteNewsServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int newsID=Integer.valueOf(request.getParameter("newid"));
System.out.println("newsID:"+newsID);
NewService service=new NewService();
service.DeleteNews(newsID);
request.getRequestDispatcher("ShowListServlet").forward(request,response);
}
}
在NewServlet中写入DeleteNews方法
public void DeleteNews(int newsID) {
String sql="delete from News where NewsID='"+newsID+"'";
SqlHelper.executeQuery(sql);
};
完成删除功能
编辑功能：
在NewServlet写入GetNews方法
public News GetNews(int newsID) throws SQLException { String sql="Select * from News where NewsID='"+newsID+"'"; ResultSet rs; rs=SqlHelper.executeQuery(sql); News news = new News(); if (rs.next()) { news.setNewid(rs.getInt("NewsID")); news.setTitle(rs.getString("Title")); news.setNewcontent(rs.getString("NewsContent")); news.setAuthor(rs.getString("Author")); news.setWritedate(rs.getDate("NewsData")); } return news; };
创建editServlet类
@WebServlet("/editServlet")
public class editServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public editServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int newsID=Integer.valueOf(request.getParameter("newid"));
System.out.println("newsID:"+newsID);
NewService service=new NewService();
try {
News news=service.GetNews(newsID);
request.setAttribute("news", news);
request.getRequestDispatcher("EditNews.jsp").forward(request,response);
} catch (SQLException e) {
e.printStackTrace();
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
EditNews.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <form action="SaveNewServlet" method="post"> 新闻ID<input type="text" name="newid" value="${news.newid}"/> 新闻标题<input type="text" name="title" value="${news.title}"/> 新闻内容<input type="text" name="newcontent" value="${news.newcontent}"/> 作者<input type="text" name="author" value="${news.author}"/> 时间<input type="text" name="writedate" value="${news.writedate}"/> <input type="submit" value="更新"/> </form> </body> </html>
jsp效果
在NewServlet写入UpdateNews方法
public void UpdateNews(News news) {
String sqltitle="update News set Title='"+news.getTitle()+"' where NewsID='"+news.getNewid()+"'";
String sqlauthor="update News set Author='"+news.getAuthor()+"' where NewsID='"+news.getNewid()+"'";
String sqlcontent="update News set NewsContent='"+news.getNewcontent()+"' where NewsID='"+news.getNewid()+"'";
SqlHelper.executeUpdate(sqltitle);
SqlHelper.executeUpdate(sqlauthor);
SqlHelper.executeUpdate(sqlcontent);
};
创建SaveNewServlet类
@WebServlet("/SaveNewServlet")
public class SaveNewServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public SaveNewServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//request.setCharacterEncoding("utf-8");
//response.setContentType("text/html;charset=utf-8");
News news=new News();
news.setNewid(Integer.valueOf(request.getParameter("newid")));
news.setAuthor(request.getParameter("author"));
news.setTitle(request.getParameter("title"));
news.setNewcontent(request.getParameter("newcontent"));
String strdate=request.getParameter("writedate");
SimpleDateFormat sDateFormat=new SimpleDateFormat();
Date date = null;
try {
date = sDateFormat.parse(strdate);
} catch (ParseException e) {
e.printStackTrace();
}
news.setWritedate(date);
System.out.println(news.getNewcontent());
NewService service=new NewService();
service.UpdateNews(news);
request.getRequestDispatcher("ShowListServlet").forward(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
修改过程发现输入中文会产生乱码，故添加过滤器，添加过滤器过程不再叙述
修改功能完成
添加功能：
在NewServlet写入GetNews方法
public void AddNews(News news) {
String sql="insert into News (Title,NewsContent,Author)"
+ "values('"+news.getTitle()+"','"+news.getNewcontent()+"','"+news.getAuthor()+"');";
SqlHelper.executeUpdate(sql);
};
改一下ShowList.jsp，把添加新闻的那个超链接改为<a href="AddNews.jsp">+添加新闻</a>
创建AddNewsServlet
@WebServlet("/AddNewsServlet")
public class AddNewsServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public AddNewsServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
News news=new News();
news.setAuthor(request.getParameter("author"));
news.setTitle(request.getParameter("title"));
news.setNewcontent(request.getParameter("newcontent"));
NewService service=new NewService();
service.AddNews(news);
request.getRequestDispatcher("ShowListServlet").forward(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
创建AddNews.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <form action="AddNewsServlet" method="post"> 新闻标题<input type="text" name="title" /> 新闻内容<input type="text" name="newcontent" /> 作者<input type="text" name="author"/> <input type="submit" value="添加"/> </form> </body> </html>
完成添加功能
查看功能：
创建viewServlet
@WebServlet("/viewServlet")
public class viewServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public viewServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int newsID=Integer.valueOf(request.getParameter("newid"));
NewService service=new NewService();
try {
News news=service.GetNews(newsID);
request.setAttribute("news", news);
request.getRequestDispatcher("view.jsp").forward(request,response);
} catch (SQLException e) {
e.printStackTrace();
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
随便写个view.jsp，此处不再去找新模板了
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> 新闻ID：${news.newid}<br/> 新闻标题${news.title}<br/> 新闻内容${news.newcontent}"<br/> 作者${news.author}<br/> 时间${news.writedate}<br/> </body> </html>
查看功能完成
