jsp与servlet之间跳转的路径设置

jsp与servlet之间跳转的路径设置

一、JSP、Servlet中的相对路径
a) 在JSP中

“/”代表站点（服务器）根目录http://127.0.0.1/

b) 在Servlet中

“/”代表Web应用的根目录http://127.0.0.1/JSP_Servlet_Path/

request.getRequestDispatcher("/a/a.jsp").forward(request, response);

相对路径/a/a.jsp中/相对于web应用的根目录，所以相当于请求跳转到绝对路径

http://127.0.0.1/JSP_Servlet_Path/a/a.jsp

response.sendRedirect("/JSP_Servlet_Path/b/b.jsp");

因为重定向中的方法是传递给浏览器，用于重新发送请求的，而在浏览器端“/”代表，相对于站点根目录http://127.0.0.1/，所以这里必须要加上/JSP_Servlet_Path，这样浏览器重新请求的地址为：http://127.0.0.1/JSP_Servlet_Path/b/b.jsp

package com.jsp_servlet_path.rqq;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class JSP_Servlet extends HttpServlet {
@Override
public voiddoGet(HttpServletRequest request, HttpServletResponse response)
        throwsServletException, IOException {
           doPost(request,response);
}
@Override
public voiddoPost(HttpServletRequest request, HttpServletResponse response)
             throwsServletException, IOException {
           System.out.println(request.getContextPath());

//请求转发，在服务器端，"/"代表（相对于）web应用http://localhost:8000/JSP_Servlet_Path/

           //所以请求转发的绝对路径为http://localhost:8000/JSP_Servlet_Path/a/a.jsp

//                 request.getRequestDispatcher("/a/a.jsp").forward(request,response);

           //请求重定向，将方法中的地址参数传递给浏览器，让浏览器重新发送请求，

           //"/"代表（相对于）服务器站点http://localhost:8000/

           //所以相当于浏览器重新请求了绝对路径http://localhost:8000/JSP_Servlet_Path/b/b.jsp

           response.sendRedirect("/JSP_Servlet_Path/b/b.jsp");

//                 response.sendRedirect(request.getContextPath()+ "/b/b.jsp");
}
}

二、JSP与Servlet相互访问

package javaBean;

import java.sql.*;

public class DBConnection {
	private static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
	private static String url = "jdbc:sqlserver://127.0.0.1:1433;DatabaseName=design";
	private static String userName = "sa";
	private static String userPassword = "123456";
	static Connection conn = null;
	public static Connection getConnection(){
		
		try {
			Class.forName(driver);
			conn = DriverManager.getConnection(url, userName, userPassword);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e){
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}
	public static void closeDB(Connection conn, PreparedStatement pstm, ResultSet rs){
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (pstm != null) {
			try {
				pstm.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}