dbselectservlet.java

JAVA编程百例书中各章节的所有例子的源代码,包括套接字编程

package ch03.section05;

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

import ch03.section04.*;

public class DBSelectServlet
    extends HttpServlet {
  String sqlStr;
  static final private String CONTENT_TYPE = "text/html; charset=gb2312";
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    response.setContentType(CONTENT_TYPE);
    PrintWriter out = response.getWriter();
    DBOperator db = new DBOperator();
    HttpSession session = request.getSession();
    try {
      String studentID = request.getParameter("studentID");
      if (studentID == null || studentID.equals("")) {
        sqlStr =
            "select studentID,studentName,studentAge,studentGrade from ch03section04 ";
        ResultSet set = db.executeQuery(sqlStr, new String("access"));
        session.setAttribute("set", set);
        response.sendRedirect("../ch03/section05/DBModifySet.jsp");
        return;
      }
      else {
        sqlStr =
            "select studentID,studentName,studentAge,studentGrade from ch03section04  where studentID = " +
            studentID + "";
        ResultSet set = db.executeQuery(sqlStr, new String("access"));
        session.setAttribute("set", set);
        session.setAttribute("studentID", studentID);
        response.sendRedirect("../ch03/section05/ModifyDOSet.jsp");
        return;
      }

    }
    catch (Exception ex) {
      System.out.println(ex.toString());
    }
    finally {
    }
  }

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

  public void destroy() {
  }
}