oracleservlet.java

j2ee写的管理程序

package zjp;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.util.*;



public class oracleServlet extends HttpServlet
{
	public void doGet(HttpServletRequest req,HttpServletResponse res)
		throws IOException ,ServletException	
	{
		String action = req.getParameter("action");		
		
		
		if(action ==null){
			student s = new student();
			req.setAttribute("thestudent",s);
			req.setAttribute("action","add");
		}
		else if(action.equals("modify")){
			try
			{
				String id =req.getParameter("id");
				ResultSet rs = stm.executeQuery("select * from student where id ="+id);
				student s = new student();
				if(rs.next()){
				s.id = rs.getString("id");
				s.name = rs.getString("name");
				s.grade = rs.getString("grade");
				s.address = rs.getString("address");
				}
				req.setAttribute("thestudent",s);
				req.setAttribute("action","modify");
			}
			catch (Exception e)
			{
				System.out.print("error1");
				e.printStackTrace();
			}
			
		}
		else if(action.equals("delete"))
		{
			try{
			CallableStatement proc = null;
			proc = conn.prepareCall("{ call delete_student(?) }");
			int id = Integer.parseInt(req.getParameter("id"));
			System.out.println(id);
			proc.setInt(1, id);
			//proc.registerOutParameter(2, Types.VARCHAR);
			proc.execute();
			//String testPrint = proc.getString(2);
			}
			catch(Exception e){
				System.out.print("error0");
				e.printStackTrace();
			}
			student s = new student();
			req.setAttribute("thestudent",s);
			req.setAttribute("action","add");
		}

		try
		{
			ResultSet rs = stm.executeQuery("select * from student order by id");
			ArrayList<student> students = new ArrayList<student>();
			while(rs.next()){
					student temp = new student();
					temp.name = rs.getString("name");
					temp.address = rs.getString("address");
					temp.id = rs.getString("id");
					temp.grade = rs.getString("grade");
					students.add(temp);
					System.out.println(temp);
			}

			req.setAttribute("students",students);
		}
		catch (Exception e)
		{
				System.out.print("error3");
				e.printStackTrace();
		}
		RequestDispatcher rd = req.getRequestDispatcher("/show.jsp");
		rd.forward(req,res);

	}

	public void doPost(HttpServletRequest req,HttpServletResponse res)
		throws IOException ,ServletException
	{
		String action = req.getParameter("action");
		if(action.equals("modify")){
				try{
			CallableStatement proc = null;
			proc = conn.prepareCall("{ call update_student(?,?,?,?) }");
			int id = Integer.parseInt(req.getParameter("id"));
			String name = req.getParameter("name");
			String address = req.getParameter("address");
			int grade = Integer.parseInt(req.getParameter("grade"));
			System.out.println(id);
			proc.setString(1, name);
			proc.setString(2,address);
			proc.setInt(3,grade);
			proc.setInt(4,id);
			//proc.registerOutParameter(2, Types.VARCHAR);
			proc.execute();
			//String testPrint = proc.getString(2);
			}
			catch(Exception e){
				System.out.print("error4");
				e.printStackTrace();
			}
		}
		else if(action.equals("add")){
		
		try{
			CallableStatement proc = null;
			proc = conn.prepareCall("{ call insert_into_student(?,?,?) }");
			String name = req.getParameter("name");
			String address = req.getParameter("address");
			int grade = Integer.parseInt(req.getParameter("grade"));
			proc.setString(1, name);
			proc.setString(2,address);
			proc.setInt(3,grade);
			//proc.registerOutParameter(2, Types.VARCHAR);
			proc.execute();
			//String testPrint = proc.getString(2);
			}
			catch(Exception e){
				System.out.print("error5");
				e.printStackTrace();
			}
		
		}
		
		student s =new student();
		req.setAttribute("thestudent",s);
		req.setAttribute("action","add");
		try
		{
			ResultSet rs = stm.executeQuery("select * from student order by id");
			ArrayList<student> students = new ArrayList<student>();
			while(rs.next()){
					student temp = new student();
					temp.name = rs.getString("name");
					temp.address = rs.getString("address");
					temp.id = rs.getString("id");
					temp.grade = rs.getString("grade");
					students.add(temp);
					System.out.println(temp);
			}

			req.setAttribute("students",students);
		}
		catch (Exception e)
		{
				System.out.print("error3");
				e.printStackTrace();
		}
		RequestDispatcher rd = req.getRequestDispatcher("/show.jsp");
		rd.forward(req,res);
	}

	public void init()
	throws ServletException	
	{
		String drivername = "oracle.jdbc.driver.OracleDriver";
		String username = "system";
		String password = "admin";
		String url="jdbc:oracle:thin:@localhost:1521:orcl";
		//String url="jdbc:oracle:thin:@localhost:1521:orcl";
		try
		{
			Class.forName(drivername);
			this.conn= DriverManager.getConnection(url,username,password);
			this.stm = conn.createStatement();
			System.out.print("OK ");

		}
		catch (Exception e)
		{
			System.out.print("error");
			e.printStackTrace();
		}
	}
		private Statement stm;
		private Connection conn;
}