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？

Question

我的Java文件是：

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。

如果单击button1，则将仅method1被调用；如果单击，button2则将仅method2执行；如果button3，则仅method3，依此类推。

我该如何实现？

Answer 1

只需给各个按钮元素一个唯一的名称即可。按下按钮后，按钮的名称可用作请求参数，就像输入元素一样。您只需要确保按钮输入的type="submit"in <input type="submit">和<button type="submit">and not一样 type="button"，这仅呈现一个“死”按钮，仅用于onclick填充所有内容。例如<form action="${pageContext.request.contextPath}/myservlet" method="post">&nbsp; &nbsp; <input type="submit" name="button1" value="Button 1" />&nbsp; &nbsp; <input type="submit" name="button2" value="Button 2" />&nbsp; &nbsp; <input type="submit" name="button3" value="Button 3" /></form>与@WebServlet("/myservlet")public class MyServlet extends HttpServlet {&nbsp; &nbsp; @Override&nbsp; &nbsp; protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {&nbsp; &nbsp; &nbsp; &nbsp; MyClass myClass = new MyClass();&nbsp; &nbsp; &nbsp; &nbsp; if (request.getParameter("button1") != null) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method1();&nbsp; &nbsp; &nbsp; &nbsp; } else if (request.getParameter("button2") != null) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method2();&nbsp; &nbsp; &nbsp; &nbsp; } else if (request.getParameter("button3") != null) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method3();&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // ???&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);&nbsp; &nbsp; }}另外，也可以使用<button type="submit">代替<input type="submit">，然后为它们赋予相同的名称，但使用唯一的值。的值<button>将不会用作标签，您只需将自己指定为孩子即可。例如<form action="${pageContext.request.contextPath}/myservlet" method="post">&nbsp; &nbsp; <button type="submit" name="button" value="button1">Button 1</button>&nbsp; &nbsp; <button type="submit" name="button" value="button2">Button 2</button>&nbsp; &nbsp; <button type="submit" name="button" value="button3">Button 3</button></form>与@WebServlet("/myservlet")public class MyServlet extends HttpServlet {&nbsp; &nbsp; @Override&nbsp; &nbsp; protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {&nbsp; &nbsp; &nbsp; &nbsp; MyClass myClass = new MyClass();&nbsp; &nbsp; &nbsp; &nbsp; String button = request.getParameter("button");&nbsp; &nbsp; &nbsp; &nbsp; if ("button1".equals(button)) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method1();&nbsp; &nbsp; &nbsp; &nbsp; } else if ("button2".equals(button)) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method2();&nbsp; &nbsp; &nbsp; &nbsp; } else if ("button3".equals(button)) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; myClass.method3();&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // ???&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);&nbsp; &nbsp; }}

Answer 2

<form method="post" action="servletName">&nbsp; &nbsp;&nbsp; &nbsp; &nbsp;<input type="submit" id="btn1" name="btn1"/>&nbsp; &nbsp; &nbsp;<input type="submit" id="btn2" name="btn2"/></form>&nbsp;&nbsp;在按下它时，请求将转到servlet页面上的servlet，检查按下了哪个按钮，然后相应地将所需的方法作为objectName.method调用

Answer 3

如果您有web.xml，那么HTML / JSP<form action="${pageContext.request.contextPath}/myservlet" method="post">&nbsp; &nbsp; <input type="submit" name="button1" value="Button 1" /></form>web.xml<servlet>&nbsp; &nbsp; &nbsp; &nbsp; <display-name>Servlet Name</display-name>&nbsp; &nbsp; &nbsp; &nbsp; <servlet-name>myservlet</servlet-name>&nbsp; &nbsp; &nbsp; &nbsp; <servlet-class>package.SomeController</servlet-class></servlet><servlet-mapping>&nbsp; &nbsp; <servlet-name>myservlet</servlet-name>&nbsp; &nbsp; <url-pattern>/myservlet</url-pattern></servlet-mapping>Java SomeController.javapublic void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {&nbsp; &nbsp; &nbsp; &nbsp; System.out.println("Write your code below");}