write.java

采用jsp+servlet+javabean

package guestbook;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;
import javax.sql.DataSource;

public class write extends HttpServlet {
  private static final String CONTENT_TYPE = "text/html; charset=GB2312";
  private DataSource dataSource=null;
  //Initialize global variables
  public void init() throws ServletException {
    Init init=new Init(getServletContext().getRealPath("/"));
    dataSource=LinkDB.getDB();
    if (dataSource==null) {
      LinkDB.setDB(init.getDriverName(),init.getDBURL(),init.getDBUser(),init.getDBPassword());
      dataSource=LinkDB.getDB();
    }
  }
  //Process the HTTP Get request
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    response.sendRedirect("write.jsp");
    return;
  }
  //Process the HTTP Post request
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("GB2312");
    response.setContentType(CONTENT_TYPE);
    PrintWriter out=response.getWriter();
    String useremail="";
    String userqq="";
    String content=request.getParameter("content");
    if(content.getBytes().length>1000){
      out.println("<script>alert('留言内容太长，请不要超过500字');document.location='javascript:history.go(-1);'</script>");
      return;
    }
    if(!Head.checkUserLogin(request)){
      useremail = request.getParameter("useremail");
      userqq = request.getParameter("userqq");
      if (!Check.checkCode(".+\\@.+\\..+", useremail) ||
          (useremail.getBytes().length > 50) ||!Check.checkCode("^\\d{5,9}$",userqq)) {
        out.println("<script>alert('输入资料格式有错误');document.location='javascript:history.go(-1);'</script>");
        return;
      }
      else{
        useremail=Check.insteadCode(useremail,"'","''");
      }
    }
    String username=Head.getUserid();
    content=Check.insteadCode(content,"'","''");
    content=Check.toHTML(content);
    String writetime=Head.getTime();
    Connection conn=null;
    Statement stmt=null;
    try{
      conn=dataSource.getConnection();
      stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
      if (!username.equals("I am a guest")) {
        ResultSet rs = stmt.executeQuery(
            "select * from userinfo where username='" + username + "'");
        if (rs.next()) {
          userqq = rs.getString("userqq").trim();
          useremail = rs.getString("useremail").trim();
          rs.close();
        }
        else {
          out.println("<script>alert('数据库出错');document.location='index.jsp';</script>");
          rs.close();
          return;
        }
      }
      stmt.executeUpdate("insert into guestbook values('"+username+"','"+userqq+"','"+useremail+"',' ','','"+content+"','"+writetime+"')");
      out.println("<script>alert('留言成功');document.location='index.jsp';</script>");
    }
    catch(SQLException e){
      out.println(e);
    }
    finally {
      try{
        stmt.close();
        conn.close();
        LinkDB.shutdownDataSource(dataSource);
      }
      catch(SQLException e) {
        out.println(e);
      }
    }
  }
}