如何在 JSP 中特定按钮的单击/提交事件上调用特定的 Java 方法? [英] How do I call a specific Java method on a click/submit event of a specific button in JSP?

问题描述

我的 Java 文件是:

My Java file is:

public class MyClass {

    public void method1() {    
        // some code
    }

    public void method2() {
        //some code
    }

    public void method3() {
        //some code
    }
}

在我的 JSP 页面中，我有三个 HTML 按钮.

In my JSP page I have three HTML buttons.

如果我点击button1，那么只会调用method1，如果我点击button2，那么只会调用method2code> 将执行，如果 button3，则只有 method3，依此类推.

If I click on button1, then only method1 will be called, if I click on button2 then only method2 will execute, and if button3, then only method3, and so on.

我怎样才能做到这一点?

How can I achieve this?

推荐答案

只需给各个按钮元素一个唯一的名称即可.按下时，按钮的名称可用作请求参数，就像输入元素一样.

Just give the individual button elements a unique name. When pressed, the button's name is available as a request parameter the usual way like as with input elements.

您只需要确保按钮输入具有 type="submit" 如 <input type="submit"> 和 <button type="submit"> 和 not type="button"，它只为 onclick<渲染一个死"按钮/code> 东西和所有.

You only need to make sure that the button inputs have type="submit" as in <input type="submit"> and <button type="submit"> and not type="button", which only renders a "dead" button purely for onclick stuff and all.

例如

<form action="${pageContext.request.contextPath}/myservlet" method="post">
    <input type="submit" name="button1" value="Button 1" />
    <input type="submit" name="button2" value="Button 2" />
    <input type="submit" name="button3" value="Button 3" />
</form>

与

@WebServlet("/myservlet")
public class MyServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        MyClass myClass = new MyClass();

        if (request.getParameter("button1") != null) {
            myClass.method1();
        } else if (request.getParameter("button2") != null) {
            myClass.method2();
        } else if (request.getParameter("button3") != null) {
            myClass.method3();
        } else {
            // ???
        }

        request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);
    }

}

或者，使用 而不是 ，然后你可以给他们所有的相同的名称，但具有唯一的值. 的值不会用作标签，您可以将自己指定为孩子.

Alternatively, use <button type="submit"> instead of <input type="submit">, then you can give them all the same name, but an unique value. The value of the <button> won't be used as label, you can just specify that yourself as child.

例如

<form action="${pageContext.request.contextPath}/myservlet" method="post">
    <button type="submit" name="button" value="button1">Button 1</button>
    <button type="submit" name="button" value="button2">Button 2</button>
    <button type="submit" name="button" value="button3">Button 3</button>
</form>

与

@WebServlet("/myservlet")
public class MyServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        MyClass myClass = new MyClass();
        String button = request.getParameter("button");

        if ("button1".equals(button)) {
            myClass.method1();
        } else if ("button2".equals(button)) {
            myClass.method2();
        } else if ("button3".equals(button)) {
            myClass.method3();
        } else {
            // ???
        }

        request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);
    }

}

另见:

• Servlet 返回HTTP 状态 404 请求的资源 (/servlet) 不可用"
• 如何通过单击 JSP 页面中的超链接或按钮将当前项传递给 Java 方法?

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