HttpServletRequest获取URL、URI

从Request对象中可以获取各种路径信息，以下例子： 

假设请求的页面是index.jsp,项目是WebDemo，则在index.jsp中获取有关request对象的各种路径信息如下

import java.io.IOException;
import java.io.PrintWriter;

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

public class test extends HttpServlet {

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

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        
        String getContextPath = request.getContextPath();  
        String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+getContextPath+"/";  
        String getRemoteAddress=request.getRemoteAddr();  
        String getServletPath =request.getServletPath();  
        String getServletContext_getRealPath =request.getServletContext.getRealPath("/");  
        String getRequestURL =request.getRequestURL().toString();
        String getRequestURI =request.getRequestURI();
        String getQueryString =request.getQueryString();
        String getRemoteUser =request.getRemoteUser();  
        out.println("getContextPath:"+ getContextPath +"<br>");  
        out.println("basePath:"+basePath+"<br>");  
        out.println("getRemoteAddress:"+ getRemoteAddress +"<br>");  
        out.println("getServletPath:"+ getServletPath +"<br>");  
        out.println("getServletContext_getRealPath:"+ getServletContext_getRealPath +"<br>"); 
        out.println("getRequestURL:"+ getRequestURL +"<br>");
        out.println("getRequestURI:"+ getRequestURI +"<br>");  
        out.println("getQueryString:"+ getQueryString +"<br>");  
        out.println("getRemoteUser:"+ getRemoteUser +"<br>"); 
    }
}

结果： 

getContextPath:/WebDemo 

basePath:http://localhost:8683/WebDemo/ 

getRemoteAddress:127.0.0.1 

getServletPath:/ welcome.jsp 

getServletContext_getRealPath:D:apache-tomcat-6.0.13webappsWebDemo 

getRequestURL: http://localhost:8683/WebDemo/welcome.jsp 

getRequestURI:/WebDemo/welcome.jsp 

getRequestQueryString: userName=Jhon

getRemoteUser:null  

注意：
request.getServletContext().getRealPath("/")等价于request.getRealPath("/")，但是request.getRealPath("/")方法现在已经被移除。