關於springMVC和傳統servlet框架從jsp頁面向後臺請求url問題
經過實驗 發現
servlet和springmvc向後臺傳送請求都是根據request.getServletPath()來獲取請求的
如果jsp中沒有<base href="<%=basePath%>">則向後臺的請求會自動解析到專案根目錄下 加上以後會自動解析到檔案的當前目錄下
舉個例子
如上圖專案(兩個jsp內容一樣)
jsp內容
Test是個servlet程式碼如下<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!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=UTF-8"> <title>Insert title here</title> </head> <body> <form action="login.action" method="post"> 使用者名稱<input type="text" name="userName"> 密碼<input type="text" name="password"> <input type="submit" value="submit"> </form> </body> </html>
1.此時瀏覽器輸入http://localhost:8080/TestServlet/page/NewFile.jsppackage com; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class Test */ public class Test extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public Test() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("request.getServletPath()="+request.getServletPath()); System.out.println("request.getContextPath()="+request.getContextPath()); } }
控制檯輸出
request.getServletPath()=/page/login.action
request.getContextPath()=/TestServlet
2.瀏覽器輸入http://localhost:8080/TestServlet/page/a/NewFile.jsp
控制檯輸出
request.getServletPath()=/page/a/login.action
request.getContextPath()=/TestServlet
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如果在兩個jsp中加入basepath
jsp程式碼如下
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href="<%=basePath%>" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="login.action" method="post">
使用者名稱<input type="text" name="userName">
密碼<input type="text" name="password">
<input type="submit" value="submit">
</form>
</body>
</html>控制檯輸出
request.getServletPath()=/login.action
request.getContextPath()=/TestServlet
2.瀏覽器輸入http://localhost:8080/TestServlet/page/a/NewFile.jsp
控制檯輸出
request.getServletPath()=/login.action
request.getContextPath()=/TestServlet
通過以上實驗可以看出request.getServletPath()在jsp中加入basepath的時候會直接獲取到請求 如果不加會從專案根目錄開始獲取請求路徑
在springMVC中是一樣的道理 springMVC實際也是通過request.getServletPath()獲取請求的
springMVC和servlet都是根據這種獲取的請求並解析 所以當用springmvc傳送請求報404的時候後臺報no mapping時可能會是這個原因(請求路徑不對應)
ps：這個basePath程式碼
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<base href="<%=basePath%>" />