javascript 如何使 HTML 链接调用 servlet 中的 java 函数
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How do you make a HTML link call a java function within your servlet
提问by EMChamp
public class Test extends HttpServlet {
private static final long serialVersionUID = 1L;
public Test() {
super();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("<HTML><HEAD><TITLE>MovieDB</TITLE></HEAD>");
out.println("<BODY><H1>MovieDB</H1>");
out.println("<a href = '#' onclick = 'on_Click();'> Call Function </a>");
}
public void on_Click()
{
System.out.println("HELLO");
}
}
I just want the HTML Link on my page to call my java function on_Click(), what is a good way to do this?
我只是想让我页面上的 HTML 链接调用我的 java 函数 on_Click()，有什么好的方法可以做到这一点？
采纳答案by BalusC
The onclickis not Java. It's JavaScript. It's a completely different language than Java. The only things which they've in common are the first 4 characters of the language name, some keywords and a some syntax. But that's it.
该onclick不是Java的。它是JavaScript。它是一种与 Java 完全不同的语言。它们唯一的共同点是语言名称的前 4 个字符、一些关键字和一些语法。但就是这样。
Just let the link point to an URL which matches the URL pattern of the servlet mapping. Imagine that you've mapped your servlet on an URL pattern of /foo/*, then just use
只需让链接指向与 servlet 映射的 URL 模式匹配的 URL。想象一下，您已将 servlet 映射到 的 URL 模式/foo/*，然后只需使用
<a href="foo">Call function</a>
This will just call the servlet's doGet()method.
这将只调用 servlet 的doGet()方法。
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("Hello");
}
If you want to reuse the same servlet for multiple actions, just pass some action identifier along as request parameter
如果你想为多个动作重用同一个 servlet，只需传递一些动作标识符作为请求参数
<a href="foo?action=bar">Call function</a>
with in doGet()of servlet
在doGet()servlet 中
String action = request.getParameter("action"); // "bar"
or as path info
或作为路径信息
<a href="foo/bar">Call function</a>
with in doGet()of servlet
在doGet()servlet 中
String action = request.getPathInfo().substring(1); // "bar"
No need for weird JavaScript approaches/workarounds.
不需要奇怪的 JavaScript 方法/解决方法。
See also:
也可以看看：
Unrelatedto the concrete problem, HTML belongs in JSP, not in Servlet.
与具体问题无关，HTML 属于JSP，而不属于Servlet。
回答by hobberwickey
A servlet runs on your server, while HTML runs on the user's computer so you'll need to use javascript/ajax to send a request to your server to execute your on_Click function.
servlet 在您的服务器上运行，而 HTML 在用户的计算机上运行，因此您需要使用 javascript/ajax 向您的服务器发送请求以执行您的 on_Click 函数。
