java jsp初试

1.新建动态web工程

2 在WEB-INF下面的lib里面添加下面的jar包

3.拷贝c3p0-config.xml 到src下面

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
	<default-config>
		<property name="user">root</property>
		<property name="password">123456</property>
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql:///dbuser</property>
	</default-config> 
</c3p0-config> 

 4.在src下面建立包和类

package com.dxm.domain;

public class UserInfo {
	private int id;
	private String username;
	private String password;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	@Override
	public String toString() {
		return "UserInfo [id=" + id + ", username=" + username + ", password=" + password + "]";
	}
	
}

package com.dxm.utils;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DataSourceUtils {

	private static DataSource dataSource = new ComboPooledDataSource();

	private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();

	
	public static DataSource getDataSource() {
		return dataSource;
	}


	public static Connection getConnection() throws SQLException {

		Connection con = tl.get();
		if (con == null) {
			con = dataSource.getConnection();
			tl.set(con);
		}
		return con;
	}


	public static void startTransaction() throws SQLException {
		Connection con = getConnection();
		if (con != null) {
			con.setAutoCommit(false);
		}
	}

	
	public static void rollback() throws SQLException {
		Connection con = getConnection();
		if (con != null) {
			con.rollback();
		}
	}


	public static void commitAndRelease() throws SQLException {
		Connection con = getConnection();
		if (con != null) {
			con.commit(); 
			con.close();
			tl.remove();
		}
	}


	public static void closeConnection() throws SQLException {
		Connection con = getConnection();
		if (con != null) {
			con.close();
		}
	}

	public static void closeStatement(Statement st) throws SQLException {
		if (st != null) {
			st.close();
		}
	}

	public static void closeResultSet(ResultSet rs) throws SQLException {
		if (rs != null) {
			rs.close();
		}
	}

}

在建IndexServlet时候指定访问的url为/index

package com.dxm.servlet;

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

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

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import com.dxm.domain.UserInfo;
import com.dxm.utils.DataSourceUtils;



public class IndexServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		try {
			QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());
			System.out.println(qr);
			String sql="select * from tbl_user";
			List<UserInfo> userList = qr.query(sql, new BeanListHandler<UserInfo>(UserInfo.class));
//			System.out.println(userList.size());
//			for (UserInfo user : userList) {
//				response.getWriter().write(user.getUsername());
//				response.getWriter().write(user.getPassword());
//				response.getWriter().write("<br/>");
//				
//			}
			request.setAttribute("UserList", userList);
			request.getRequestDispatcher("/index.jsp").forward(request, response);
		} catch (Exception e) {
			
			e.printStackTrace();
		}
		response.getWriter().write("Hello");
	}

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

在WebContent下面新建index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ page import="com.dxm.domain.*" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
	<%  
		List<UserInfo> list = (List<UserInfo>)request.getAttribute("UserList");
		for(UserInfo user :list){
			out.write(user.getUsername());
			out.write("----");
			out.write(user.getPassword());
			out.write("<br/>");
		}
	%>
</body>
</html>

5.发布，启动tomcat以后,输入http://localhost:8080/web09263/index访问既可以显示数据