request.getRequestURL() 返回全路徑
request.getRequestURI() 返回除去host(域名或者ip)部分的路徑
request.getContextPath() 返回工程名部分,如果工程映射為/,此處返回則為空
request.getServletPath() 返回除去host和工程名部分的路徑
例如:
request.getRequestURL() http://localhost:8080/jqueryLearn/resources/request.jsp
request.getRequestURI() /jqueryLearn/resources/request.jsp
request.getContextPath()/jqueryLearn
request.getServletPath()/resources/request.jsp