本文章主要讨論以下幾種request擷取路徑的方法:
request.getServletPath()
request.getPathInfo()
request.getContextPath()
request.getRequestURI()
request.getRequestURL()
request.getServletContext().getRealPath()
以一個簡單的例子說明:
web.xml配置(注意此處的url-pattern項)
<?xml version="1.0" encoding="UTF-8"?> aab a.jsp test com.java.test.TestServlet
</servlet>
<servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>/*</url-pattern><!-- 注意此處 -->
</servlet-mapping>
TestServlet.java檔案:
package com.java.test;
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 TestServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println(“servletPath:”+req.getServletPath());
System.out.println(“contextPath:”+req.getContextPath());
System.out.println(“contextPath2:”+req.getServletContext().getContextPath());
System.out.println(“pageInfo:”+req.getPathInfo());
System.out.println(“uri:”+req.getRequestURI());
System.out.println(“url:”+req.getRequestURL());
System.out.println(“realPath:”+req.getServletContext().getRealPath("/"));
}
}
此時請求http://localhost:8080/testweb (url-pattern=/*)
列印出來的值為:
servletPath:
contextPath:/testweb
contextPath2:/testweb
pageInfo:null
uri:/testweb
url:http://localhost:8080/testweb
realPath:G:\java.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\testweb\
請求http://localhost:8080/testweb/abc 列印的值為:
servletPath:
contextPath:/testweb
contextPath2:/testweb
pageInfo:/abc
uri:/testweb/abc
url:http://localhost:8080/testweb/abc
realPath:G:\java.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\testweb\
當我們修改web.xml為如下時(注意url-pattern的改變):
<?xml version="1.0" encoding="UTF-8"?> aab a.jsp
<servlet>
<servlet-name>test</servlet-name>
<servlet-class>com.java.test.TestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>/abc/def/*</url-pattern><!-- 注意此處 -->
</servlet-mapping>
請求http://localhost:8080/testweb/abc/def/ghi/test.html (url-pattern=/abc/def/*)
列印的值為:
servletPath:/abc/def
contextPath:/testweb
contextPath2:/testweb
pageInfo:/ghi/test.html
uri:/testweb/abc/def/ghi/test.html
url:http://localhost:8080/testweb/abc/def/ghi/test.html
realPath:G:\java.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\testweb\
通過觀察列印結果,我們可以總結:
getServletPath():擷取能夠與“url-pattern”中比對的路徑,注意是完全比對的部分,的部分不包括。
getPathInfo():與getServletPath()擷取的路徑互補,能夠得到的是“url-pattern”中d的路徑部分
getContextPath():擷取項目的根路徑
getRequestURI:擷取根路徑到位址結尾
getRequestURL:擷取請求的位址連結(浏覽器中輸入的位址)
getServletContext().getRealPath("/"):擷取“/”在機器中的實際位址
getScheme():擷取的是使用的協定(http 或https)
getProtocol():擷取的是協定的名稱(HTTP/1.11)
getServerName():擷取的是域名(xxx.com)
getLocalName:擷取到的是IP