var url="${pageContext.request.contextPath}/AdminServlet?method=login&username="+username+‘&password=‘+password;
window.location.href="b.html";
<img src="${pageContext.request.contextPath}/checkCode" id="checkCode"/></a>
js传参
原文地址：https://www.cnblogs.com/jingxiaopu/p/8744392.html