jsp页面引用js变量值

<form action="yourJspPage.jsp" method="post">
    <input type="hidden" id="hiddenField" name="jsVariable">
    <button type="button" onclick="submitForm()">Submit</button>
</form>

<script>
function submitForm() {
    var jsVar = "someValue"; // 这里是你的JavaScript变量
    document.getElementById('hiddenField').value = jsVar;
    document.forms[0].submit();
}
</script>

<%
String jsVariable = request.getParameter("jsVariable");
%>
<p>The value of JavaScript variable is: <%= jsVariable %></p>

var jsVar = "someValue"; // 这里是你的JavaScript变量

var xhr = new XMLHttpRequest();
xhr.open('POST', 'yourJspPage.jsp', true);
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
        document.getElementById('result').innerHTML = xhr.responseText;
    }
};
xhr.send('jsVariable=' + encodeURIComponent(jsVar));

<%
String jsVariable = request.getParameter("jsVariable");
%>
<p>The value of JavaScript variable is: <%= jsVariable %></p>