基于Javaweb的图书管理系统

package allServlet; import java.io.IOException; import java.io.PrintWriter; import java.sql.*; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import basicClass.MysqlLinking; @WebServlet(name = "AddBookServlet",urlPatterns ="/AddBookServlet") public class AddBook_Servlet extends HttpServlet { private Connection conn = null; private static final long serialVersionUID = 1L; public void init(ServletConfig config) throws ServletException { (new MysqlLinking()).getLink();//连接数据库 conn = MysqlLinking.conn;//获取连接数据库的Connection对象conn } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); String bName = request.getParameter("bName");//获取填入的属性值 String writer = request.getParameter("writer"); String press = request.getParameter("press"); String presstime = request.getParameter("presstime"); String price = request.getParameter("price"); String pageNum = request.getParameter("pageNum"); String sort = request.getParameter("sort"); String barCode = request.getParameter("barCode"); if (conn != null) { try { //插入注册信息的SQL语句(使用?占位符) //添加图书属性 String sql="insert into books(bName,writer,press,presstime,pageNum,price,sort,barCode,LendNum,state,borrower) values(?,?,?,?,?,?,?,?,?,?,?)"; //创建PreparedStatement对象ps PreparedStatement ps = conn.prepareStatement(sql); //对SQL语句中的参数动态赋值 if(bName!="")//判断输入是否为空 若为空则显示错误提示 { ps.setString(1,bName); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='图书名称不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(writer!="")//判断输入是否为空 若为空则显示错误提示 { ps.setString(2,writer); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='作者不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(press!="")//判断输入是否为空 若为空则显示错误提示 { ps.setString(3,press); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='出版社不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(presstime!="") { ps.setString(4,presstime); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='出版时间不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(pageNum!="") { ps.setInt(5,Integer.valueOf(pageNum)); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='页数不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(price!="") { ps.setDouble(6,Double.valueOf(price)); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='价格不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(sort!="") { ps.setString(7,sort); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='类别不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } if(barCode!="") { ps.setString(8,barCode); }else { PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='条形码不可以为空';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } ps.setInt(9,0); ps.setString(10,"未借"); ps.setString(11,""); //执行更新操作 ps.executeUpdate(); //获取PrintWriter对象 PrintWriter out = response.getWriter(); //输出注册结果信息 out.println("<script language='javascript'>"); out.println("var str='图书添加成功！';"); out.println("alert(str);"); out.println("window.navigate('AddBook.jsp');"); out.println("</script>"); out.flush(); out.close(); } catch (Exception e) { e.printStackTrace(); } } else { response.sendError(500, "数据库连接错误！");//发送数据库连接错误提示信息 } } }