studentservlet.java

是老师给我们的一个JAVA的学生管理系统

package hit;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class StudentServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public StudentServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doPost(request,response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		DBTools db = new DBTools();
		String action = request.getParameter("action");
		if(action.equals("add"))
		{
			String sid = request.getParameter("sid");
			String sname = request.getParameter("sname");
			
			byte[] b = sname.getBytes("ISO-8859-1");
			sname = new String(b,"GB2312");
			
			int age = Integer.parseInt(request.getParameter("age"));
			String sex = request.getParameter("sex");
			String banji = request.getParameter("banji");
			String sql = "insert into student values('" + sid + "','" + sname + "'," + age + ",'" + sex + "','" + banji + "')";
			db.executeUpdate(sql);
			response.sendRedirect("student.jsp");
		}
		if(action.equals("modify"))
		{
			String sid = request.getParameter("sid");
			String sname = request.getParameter("sname");
			
			byte[] b = sname.getBytes("ISO-8859-1");
			sname = new String(b,"GB2312");
			
			int age = Integer.parseInt(request.getParameter("age"));
			String sex = request.getParameter("sex");
			String banji = request.getParameter("banji");
			String sql = "update student set sname = '" + sname + "',age = " + age + ",sex = '" + sex + "',banji = '" + banji + "' where sid = '" + sid + "'";
			db.executeUpdate(sql);
			response.sendRedirect("student.jsp");
		}
		if(action.equals("delete"))
		{
			String sid = request.getParameter("sid");
			String sql = "delete from student where sid = '" + sid + "'";
			db.executeUpdate(sql);
			response.sendRedirect("student.jsp");
		}
		//out.close();
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}