servlet.java

简单的增删改查,用servlet做的,数据库用sql2000de,适合初步学习人员

package webtier;

import java.io.IOException;
import java.util.List;

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

import bean.Bean;
import bean.ToChinese;

public class Servlet extends HttpServlet{
	
	private int Mode;
	protected void doPost(HttpServletRequest request, 
			HttpServletResponse response) throws ServletException, IOException {
		Mode=Integer.parseInt(request.getParameter("Mode"));
		switch(Mode){
		case 1:this.insert(request,response);
		       break;
		case 2:this.query(request,response);
		       break;
		case 3:this.delete(request,response);
		       break;
		case 4:this.queryone(request,response);
	           break;
		case 5:this.update(request, response);
		       break;
		}
	}	
	protected void doGet(HttpServletRequest request, 
			HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doPost(request, response);
	}
	
	public void insert(HttpServletRequest request,HttpServletResponse response){
		String name=ToChinese.toChinese(request.getParameter("name"));
		String password=ToChinese.toChinese(request.getParameter("password"));
		String insert_sql="insert into zhym values ('"+name+"','"+password+"')";
		Bean b=new Bean();
		b.executeUpdate(insert_sql);
		RequestDispatcher dis=request.getRequestDispatcher("Exercise_servlet?Mode=2");
		try {
			dis.forward(request, response);
		} catch (ServletException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void query(HttpServletRequest request,HttpServletResponse response){		
		String query_sql="select * from zhym order by id";
		Bean b=new Bean();
		List list=b.executeQuery(query_sql);
		request.setAttribute("list", list);
		RequestDispatcher dis=request.getRequestDispatcher("query.jsp");
		try {
			dis.forward(request, response);
		} catch (ServletException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void delete(HttpServletRequest request,HttpServletResponse response){
		String id=request.getParameter("id");
		String delete_sql="delete from zhym where id="+id;
		Bean b=new Bean();
		b.executeUpdate(delete_sql);
		RequestDispatcher dis=request.getRequestDispatcher("Exercise_servlet?Mode=2");
		try {
			dis.forward(request, response);
		} catch (ServletException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void queryone(HttpServletRequest request,HttpServletResponse response){
		String id=request.getParameter("id");
		String queryone_sql="select * from zhym where id="+id;
		Bean b=new Bean();
		List list=b.executeQuery(queryone_sql);
		request.setAttribute("list", list);
		RequestDispatcher dis=request.getRequestDispatcher("queryone.jsp");
		try {
			dis.forward(request, response);
		} catch (ServletException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void update(HttpServletRequest request,HttpServletResponse response){
		String id=request.getParameter("id");
		String name=ToChinese.toChinese(request.getParameter("name"));
		String password=ToChinese.toChinese(request.getParameter("password"));
		String update_sql="update zhym set name='"+name+"',password='"+password+"' where id="+id;
		Bean b=new Bean();
		b.executeUpdate(update_sql);
		RequestDispatcher dis=request.getRequestDispatcher("Exercise_servlet?Mode=2");
		try {
			dis.forward(request, response);
		} catch (ServletException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}