java 20231023-javademo

package com.itcast.servlet; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Enumeration; import java.util.Map; @WebServlet("/requestDemo4") public class requestDemo4 extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // 第一个方法 getParameter System.out.println("用户名和密码："); String username = req.getParameter("username"); String password = req.getParameter("password"); System.out.println(username); System.out.println(password); // 第二个方法 getParameterValues System.out.println("所有的参数值："); String[] hobbies = req.getParameterValues("hobby"); for (String hobby : hobbies) { System.out.println(hobby); } // 第三个方法 getParameterNames System.out.println("所有的参数名："); Enumeration<String> names = req.getParameterNames(); // names.hasMoreElements() 如果名字中还有元素 while (names.hasMoreElements()){ System.out.println(names.nextElement()); } // 第四个方法 获取键值对 System.out.println("MAP集合"); Map<String, String[]> parameterMap = req.getParameterMap(); System.out.println(parameterMap); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doGet(req, resp); } }