如何在JSP中特定按钮的单击/提交事件上调用特定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:
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.
如果单击button1，将仅调用method1；如果单击button2，则将仅执行method2；如果单击button3，则将仅执行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.
我该如何实现?
推荐答案
只需为各个按钮元素指定一个唯一的名称.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.
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">且不 type="button"一样)，它们仅为onclick全部内容.
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="${pageContext.request.contextPath}/myservlet" method="post">
<input type="submit" name="button1" value="Button 1" />
<input type="submit" name="button2" value="Button 2" />
<input type="submit" name="button3" value="Button 3" />
</form>
使用
@WebServlet("/myservlet")
public class MyServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
MyClass myClass = new MyClass();
if (request.getParameter("button1") != null) {
myClass.method1();
} else if (request.getParameter("button2") != null) {
myClass.method2();
} else if (request.getParameter("button3") != null) {
myClass.method3();
} else {
// ???
}
request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);
}
}
或者，使用<button type="submit">而不是<input type="submit">，然后可以给它们取相同的名称，但使用唯一的值. <button>的值将不会用作标签，您只能将自己指定为孩子.
Alternatively, use <button type="submit"> instead of <input type="submit">, then you can give them all the same name, but an unique value. The value of the <button> won't be used as label, you can just specify that yourself as child.
例如
<form action="${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>
使用
@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);
}
}
