javaweb零碎知识3

// 假设您已经导入了 axios
import axios from 'axios';// 获取表单元素
const form = document.getElementById('myForm');// 为表单添加 submit 事件监听器
form.addEventListener('submit', function(e) {// 阻止表单的默认提交行为e.preventDefault();// 创建 FormData 对象并从表单中获取数据const formData = new FormData(form);// 使用 axios 发送 POST 请求axios.post('http://localhost:8080/untitled2_war_exploded/ser01', formData).then(response => {// 请求成功时执行的代码console.log('表单提交成功:', response.data);// 这里可以添加代码处理服务器的响应，例如显示一个成功消息或跳转到另一个页面alert('注册成功!');}).catch(error => {// 请求失败时执行的代码console.error('表单提交失败:', error);// 这里可以添加代码处理错误，例如显示一个错误消息alert('注册失败: ' + error.message);});
});

当我使用表单默认提交方式才能使用axios.post的提交方式，当我们提交表单的按钮设置submit时就代表使用表单的按钮进行提交

如果我们给提交表的时候是使用自己蛇者的按钮（并且绑定监听事件的时候就不能使用这种形式，只能采用）

下面这种形式

 axios({url:"http://localhost:8080/untitled2_war_exploded/ser01",method:"post",params:{username,email,password}}).then(response => {// 请求成功时执行的代码console.log('表单提交成功:', response.data);}).catch(error => {// 请求失败时执行的代码console.error('表单提交失败:', error);});

设置编码格式

 请求的设置格式

 req.setCharacterEncoding("UTF-8");

回应的设置格式

 resp.setContentType("text/html; charset=UTF-8");

package com.xxx.controller;import com.xxx.controller.Param;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;/*** @author 关岁安*/
public abstract class BaseServlet extends HttpServlet {@Overrideprotected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("UTF-8");String methodName = request.getParameter("method");if (methodName == null || methodName.isEmpty()) {//返回404错误response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Method parameter is missing or empty");return;}try {System.out.println("方法名字：" + methodName);Method method = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);System.out.println("看看这里被执行到这里没？");Parameter[] parameters = method.getParameters();Object[] args = new Object[parameters.length];for (int i = 0; i < parameters.length; i++) {if (parameters[i].isAnnotationPresent(Param.class)) {Param param = parameters[i].getAnnotation(Param.class);String value = request.getParameter(param.value());args[i] = value;} else if (parameters[i].getType() == HttpServletRequest.class) {args[i] = request;} else if (parameters[i].getType() == HttpServletResponse.class) {args[i] = response;}}method.setAccessible(true);method.invoke(this, args);} catch (NoSuchMethodException e) {//e.printStackTrace();//返回500错误//response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Internal Server Error");System.out.println("拼写错误、方法参数类型不匹配");}catch (InvocationTargetException | IllegalAccessException e){e.printStackTrace();System.out.println("没有足够的权限,包装异常");}}public abstract void register(@Param("username") String username, HttpServletRequest req, HttpServletResponse resp);}

package com.xxx.controller;import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;/*** @author 关岁安**/@WebServlet("/Register")
public  class RegisterController extends BaseServlet {@Overridepublic void register(@Param("username") String username, HttpServletRequest req, HttpServletResponse resp) {System.out.println("检测一下这个注册方法是否已经被执行");// 注册逻辑System.out.println("注册用户名: " + username  + "看看是否已经获取到请求");}
}

这里还有一个动态查询

重新实现了servlet那边的方法，按照发送的方式进行封装，如果是post方式就按照post来处理逻辑
如果是get请求就按照get方法来进行处理业务逻辑

这个相较于以前可以传送对象，和param数据，可接受的数据类型变得比以前更多

package com.xxx.controller;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xxx.annotation.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;/*** @author 关岁安*/
public abstract class BaseServlet extends HttpServlet {@Overrideprotected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.getQueryString();request.setCharacterEncoding("UTF-8");String uri = request.getRequestURI();System.out.println(uri);String methodName = new StringBuffer(uri.substring(uri.lastIndexOf("/") + 1)).toString();Method method = null;Method[] methods = this.getClass().getDeclaredMethods();for (Method method1 : methods) {if("POST".equals(request.getMethod())){if(method1.getAnnotation(POST.class).value().equals(methodName)){method = method1;Parameter[] parameters = method.getParameters();Object[] args = new Object[parameters.length];for (int i = 0; i < parameters.length; i++) {Annotation[] annotations = parameters[i].getAnnotations();for (Annotation annotation : annotations) {if(annotation instanceof Param){String name = ((Param) annotation).value();args[i] = request.getParameter(name);}else if(annotation instanceof Body){ObjectMapper objectMapper = new ObjectMapper();JsonNode jsonNode = objectMapper.readTree(request.getReader());Object object = objectMapper.treeToValue(jsonNode, parameters[i].getType());args[i] = object;}else {if(parameters[i].getType() == HttpServletRequest.class){args[i] = request;}else if(parameters[i].getType() == HttpServletResponse.class){args[i] = response;}}}}try {method.invoke(this,args);} catch (IllegalAccessException e) {throw new RuntimeException(e);} catch (InvocationTargetException e) {throw new RuntimeException(e);}}}else if("GET".equals(request.getMethod())){if(method1.getAnnotation(GET.class).value().equals(methodName)){method = method1;Parameter[] parameters = method.getParameters();Object[] args = new Object[parameters.length];for (int i = 0; i < parameters.length; i++) {Annotation[] annotations = parameters[i].getAnnotations();for (Annotation annotation : annotations) {if(annotation instanceof Param){String name = ((Param) annotation).value();args[i] = request.getParameter(name);}else if(annotation instanceof Body){ObjectMapper objectMapper = new ObjectMapper();JsonNode jsonNode = objectMapper.readTree(request.getReader());Object object = objectMapper.treeToValue(jsonNode, parameters[i].getType());args[i] = object;}else {if(parameters[i].getType() == HttpServletRequest.class){args[i] = request;}else if(parameters[i].getType() == HttpServletResponse.class){args[i] = response;}}}}try {method.invoke(this,args);} catch (IllegalAccessException e) {throw new RuntimeException(e);} catch (InvocationTargetException e) {throw new RuntimeException(e);}}}}}
}