modifyreader.java

JAVA的MVC三层开发的图书馆管理系统。

package mypackage;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.PrintWriter;
import java.io.IOException;
import java.sql.*;
import javax.sql.DataSource;

public class ModifyReader extends HttpServlet 
{
  private static final String CONTENT_TYPE = "text/html; charset=GBK";

  public void init(ServletConfig config) throws ServletException
  {
    super.init(config);
  }

  public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    response.setContentType(CONTENT_TYPE);
    request.setCharacterEncoding("GBK");
    String readerID = request.getParameter("readerID");
    String readerName = request.getParameter("readerName");
    int sex = Integer.parseInt(request.getParameter("sex"));
    String maxnum = request.getParameter("maxnum");
    int success = 0;
    DataSource ds = null;
    Connection conn = null;
    Statement stmt = null;
    String sql = "update reader set readername='"+readerName+"',sex='"+sex+"',maxnum='"+maxnum+"' where readerID="+readerID;
    
    try{
      ds = (DataSource)request.getSession().getServletContext().getAttribute("DataSrc");
      conn = ds.getConnection();
      stmt = conn.createStatement();
      success = stmt.executeUpdate(sql);
      stmt.close();
      conn.close();
    }
    catch(Exception e){
      System.out.println(e.getMessage());
    }
    if(success > 0)
   request.getSession().getServletContext().getRequestDispatcher("Seccess.jsp").forward(request, response);
    else
   request.getSession().getServletContext().getRequestDispatcher("Fail.jsp").forward(request, response);
  }
}