ServletContext实现转发和读取Properties配置文件

在Servlet开发中，一般很少使用Servlet输出数据，所以需要转发机制实现Servlet向JSp等等的转发，使用Servletontext就能完成这个功能，代码如下

 

 

package com.bird.servlet;

import java.io.IOException;
/**
 * @use 使用ServletContext实现请求的转移
 * @author Bird
 */
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletDemo5 extends HttpServlet {

	private static final long serialVersionUID = 1L;

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

		String data = "aaaaaaaa";
		//数据带给JSP
		this.getServletContext().setAttribute("data", data);

		RequestDispatcher re = this.getServletContext().getRequestDispatcher("/1.jsp");//转发对象
		re.forward(request, response);
	}

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

	}

}

 

 

 

 

 

 

下面的代码为使用ServletContext实现对Properties文件的读取和输出，先把配置文件的内容写出来

 

 

url=jdbc:mysql://localhost:3306/test
username=root
password=root

 
代码如下

 

 

 

 

package com.bird.servlet;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

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

public class ServletDemo6 extends HttpServlet {

	/**
	 * @use 使用Servlet读取配置文件信息
	 * @author Bird
	 */
	private static final long serialVersionUID = 1L;

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//读取配置文件信息，其中配置文件为Properties
		InputStream in = this.getServletContext().getResourceAsStream("/WEB-INF/classes/db.properties");

		Properties pro = new Properties();
		pro.load(in);

		String url = pro.getProperty("url");
		String username = pro.getProperty("username");
		String password = pro.getProperty("password");

		System.out.println(url);
		System.out.println(username);
		System.out.println(password);

	}

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

	}

}

 
一定要注意路径的问题。。。。。