我如何调用特定的Java方法上点击/ JSP中提交特定按钮的事件？ [英] How do I call a specific Java method on click/submit event of specific button in JSP?

问题描述

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。

In my JSP page I have three HTML buttons.

如果我点击按钮1 ，那么只有方法1 将被调用，如果我点击按钮2 则仅方法2 将执行，如果按钮3 ，那么只有 method3 ，等等。

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

只要给各个按钮元素的唯一名称。当pressed，按钮的名称可以作为一个请求参数一样，与输入元素通常的方式。

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

您只需要确保该按钮输入有键入=提交在＆LT;输入类型=提交＆GT; 和＆LT;按钮式=提交＆GT; ，从而不可以 TYPE =按钮只呈现一个死按钮，纯粹是为了的onclick 的东西，所有的。

You only need to make sure that the button inputs have type="submit" as in <input type="submit"> and <button type="submit"> and thus 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);
    }

}

另外，使用＆LT;按钮式=提交＆GT; 而不是＆LT;输入类型=提交＆GT; ，那么你可以给他们所有相同的名称，而是一种独特的价值。的值＆LT;按钮方式＆gt; 将不能作为标签，你可以指定自己为孩子

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="button1">Button 2</button>
    <button type="submit" name="button" value="button1">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);
    }

}

参见：

• Servlet回报＆QUOT; HTTP状态404所请求的资源（/ servlet的）不可用＆QUOT;


• How我通过点击JSP页面的超链接或按钮通过当前项目的Java方法？



See also:

• Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"
• How do I pass current item to Java method by clicking a hyperlink or button in JSP page?

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