Question

我开始学习Java网络，我需要一些有关为什么我的代码无法正常工作的见解当我尝试提交我的代码时，我注意到当我转到页面时应该进行更改的地方什么都不会显示。

我将显示一些代码

发布方法

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import numpy as np
from scipy.integrate import solve_ivp
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from animate_plot import animate

def upward_cannon(t, y):
    return [y[1], -0.5]

def hit_ground(t, y):
    return y[0]

def apex(t,y):
    return y[1]

hit_ground.terminal = True
hit_ground.direction = -1

t0 = 0

tf = 10

sol = solve_ivp(upward_cannon, t_span=[t0, tf], y0=[90, 10], t_eval=np.arange(t0,tf, 0.01), events=[hit_ground,apex],
                dense_output=True)

linesData = { 1: [[-0.0, 0.0],[0.0, 0.0]]}#,
            # 2: [[-0.5, 0],[0.5, 0.0]]}#, 3: [[-0.5, 0],[0.5, 0]]}

pointsofInterest = {}#3: [[0.5, 0.0]]}#, 2: [[180.0, 10]]}

model_markers = np.array([])

plot_title = 'Upward Particle'
plot_legend = ['Forward Dynamics']

q_rep = sol.y.T[:,0]

fig = plt.figure()

ax = fig.add_subplot(111)

xs = np.arange(t0, tf, 0.01)

for idx in range(0,q_rep.shape[0]):   #looping statement;declare the total number of frames
    y=q_rep[idx]       # traveling Sine wave
    ax.cla()
    ax.scatter(xs[idx],y, s=50)
    plt.ylim([-10, 190])
    plt.xlim([-100, 100])
    plt.pause(0.001)
plt.show()

获取方法

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

        String titulo = request.getParameter("titulo");
        String imagem = request.getParameter("imagem");
        String descricao = request.getParameter("descricao");
        String categoria = request.getParameter("categoria");

        Noticias noticia = new Noticias();



         System.out.println(titulo);
        noticia.setTitulo(titulo);
        System.out.println(descricao);
        noticia.setDescricao(descricao);
        System.out.println(categoria);
        noticia.setCategoria(categoria);
        System.out.println(categoria);
        noticia.setImagem(imagem);

        Noticias.dados.add(noticia);

        response.sendRedirect(categoria);
    }

输入

      @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

我的sysout不显示任何输出。而且它在页面上没有显示任何更改，我想帖子没有初始化

Answer 1

如果要提交表单，则必须在表单标签中提及方法和操作属性。

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

该servlet也应该出现在web.xml中。

您可以点击此链接https://www.journaldev.com/1877/servlet-tutorial-java

如何使用输入和过帐方法

1 个答案: