Question

我从主servlet调用另一个servlet，通过实现jsp会很容易，但我这个实验的目的是只使用servlet，请帮助

Answer 1

您不能在课程中多次覆盖某个方法，因此您无法多次覆盖doPost。

如果你的意思是超载它，那就没有充分的理由这样做。最后，Servlet容器只会调用其中一个方法。

如果要使用单个Servlet处理多种请求，可以发送一个参数来指示您将执行的操作。例如：

@WebServlet("/person")
public class PersonCRUDServlet extends HttpServlet {

    private static final String ADD = "add";
    private static final String DELETE = "delete";

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        String action = request.getParameter("action");
        //using if assuming you work with Java SE 6
        if (ADD.equals(action)) {
            add(request, response);
        } else
        if (DELETE.equals(action)) {
            delete(request, response);
        } else {
            //submitted action can't be interpreted
            //or no action was submitted
            errorForward(request, response);
        }
    }

    private void add(HttpServletRequest request, HttpServletResponse response) {
        //handle logic for add operation...
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) {
        //handle logic for delete operation...
    }

    private void errorForward(HttpServletRequest request, HttpServletResponse response) {
        //handle logic for delete operation...
    }
}

请注意，手动处理需要做很多工作（这就是Java Web MVC框架存在的原因）。你也可以参考

我可以多次覆盖servlet的doPost方法

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