jsp Request獲取url信息的各種方法比較

    從Request對象中可以獲取各種路徑信息，以下例子：  
    假設請求的頁面是index.jsp,項目是WebDemo，則在index.jsp中獲取有關request對象的各種路徑信息如下  
    String path = request.getContextPath();  
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";  
    String remoteAddress=request.getRemoteAddr();  
    String servletPath=request.getServletPath();  
    String realPath=request.getRealPath("/");  
    String remoteUser=request.getRemoteUser();  
    String requestURI=request.getRequestURI();  
    out.println("path:"+path+"<br>");  
    out.println("basePath:"+basePath+"<br>");  
    out.println("remoteAddr:"+remoteAddress+"<br>");  
    out.println("servletPath:"+servletPath+"<br>");  
    out.println("realPath:"+realPath+"<br>");  
    out.println("remoteUser:"+remoteUser+"<br>");  
    out.println("requestURI:"+requestURI+"<br>");  
    結果：  
    path:/WebDemo  
    basePath:http://localhost:8683/WebDemo/  
    remoteAddr:127.0.0.1  
    servletPath:/index.jsp  
    realPath:D:\apache-tomcat-6.0.13\webapps\WebDemo\  
    remoteUser:null  
    requestURI:/WebDemo/index.jsp  
    從上不難看出request各個對應方法所代表的含義  

    從request獲取各種路徑總結：  
    request.getRealPath("url");//虛擬目錄映射為實際目錄  
    request.getRealPath("./");//網頁所在的目錄  
    request.getRealPath("../");//網頁所在目錄的上一層目錄  
    假定你的web application(web應用)名稱為news，你的瀏覽器中輸入請求路徑：http://localhost:8080/uploading/load.jsp  
    request.getContextPath()  =>  /uploading  
    request.getServletPath()  =>  /load.jsp  
    request.getRequestURL()  =>  http://localhost:8080/uploading/load.jsp  
    request.getRealPath("/")  =>   F:\learn\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\uploading\  
    現在request.getRealPath("/") 這個方法已經不推薦使用了  
    可以使用  
    ServletContext.getRealPath(java.lang.String)  instead.  
    request.getSession().getServletContext().getRealPath() 得到工程文件的實際物理路徑,也就是絕對地址

 

 

 

 

 //Returns the part of this request's URL from the protocol name up to the query string in the first line of the HTTP request  
         //  eg.     /manage/editExam.domethod=goExamSet&type=U  
      String url = request.getRequestURI();    
      //The returned URL contains a protocol, server name, port number, and server path, but it does not include query string parameters  
        //eg.      http://127.0.0.1:8080/manage/editExam.domethod=goExamSet&type=U  
      StringBuffer url_buffer = request.getRequestURL();  
  HttpServletRequest 的這兩種方法都只能得到不包含參數的請求url，區別如下：  
1 前者返回相對路徑，后者返回完整路徑  
2 前者返回string ，后者返回stringbuffer  
得到完整請求url可以通過如下方法，getQueryString()得到的是url后面的參數串，和前者相加就是帶參數的請求路徑了  
  String queryString = request.getQueryString();  
ring fullPath = url + queryString;   // 或者是url_buffer.toString()+queryString;