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">

    <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);

    }

}

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">

    <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);

    }

}

Answer 2

<form method="post" action="servletName">   

     <input type="submit" id="btn1" name="btn1"/>

     <input type="submit" id="btn2" name="btn2"/>

</form>  

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">

    <input type="submit" name="button1" value="Button 1" />

</form>

web.xml

<servlet>

        <display-name>Servlet Name</display-name>

        <servlet-name>myservlet</servlet-name>

        <servlet-class>package.SomeController</servlet-class>

</servlet>

<servlet-mapping>

    <servlet-name>myservlet</servlet-name>

    <url-pattern>/myservlet</url-pattern>

</servlet-mapping>

Java SomeController.java

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        System.out.println("Write your code below");

}