processscore.java

这是一个可以在手机客户端运行的选课系统 这个是客户端

package course.select;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import jdbc.*;
import java.sql.*;
import exception.*;
import constants.Constant;

/**
 * @version 	1.0
 * @author
 */
public class ProcessScore extends HttpServlet implements Servlet {

	/**
	* @see javax.servlet.http.HttpServlet#void (javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	*/
	public void doGet(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
			processRequest(req,resp);
	}

	/**
	* @see javax.servlet.http.HttpServlet#void (javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	*/
	public void doPost(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
			processRequest(req,resp);
	}

	/**
	 * @param req
	 * @param resp
	 */
	private void processRequest(HttpServletRequest req, HttpServletResponse resp) throws IOException
		// TODO 自动生成方法存根
	{
		String studentID=req.getParameter("user");
		int term=Integer.parseInt(req.getParameter("term"));
		
		OutputStream os=resp.getOutputStream();
		DataOutputStream dos=new DataOutputStream(os);
		//获得向MIDlet返回所有信息的流
		try
		{
			DatabaseConnection connection=new DatabaseConnection();
			//产生与数据库连接的类的实例，可能抛出SQLException
			connection.connect();
			String [] scores=null;
			if(connection.getScoreNum(studentID,0)==0)
				throw new UserNotExistException();
			scores=connection.getScore(studentID,term);
			dos.writeInt(connection.getScoreNum(studentID,term));
			//1代表查询成功 
			for(int i=0;i<scores.length;i++)
				dos.writeUTF(scores[i]);
		}
		catch(UserNotExistException e)
		{
			dos.writeInt(-6);
			//-1代表班级不存在
		}
		catch(DriverException e)
		{
			dos.writeInt(-3);
			//驱动错误
		}		
		catch(SQLException e)
		{
			dos.writeInt(-3);
			//与数据库连接错误
		}
	}
}